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// C++ Program to convert a Binary Tree // to a Circular Doubly Linked List #include <iostream> using namespace std; // To represents a node of a Binary Tree struct Node { struct Node *left, *right; int data; }; // A function that appends rightList at the end // of leftList. Node* concatenate(Node* leftList, Node* rightList) { // If either of the list is empty // then return the other list if (leftList == NULL) return rightList; if (rightList == NULL) return leftList; // Store the last Node of left List Node* leftLast = leftList->left; // Store the last Node of right List Node* rightLast = rightList->left; // Connect the last node of Left List // with the first Node of the right List leftLast->right = rightList; rightList->left = leftLast; // Left of first node points to // the last node in the list leftList->left = rightLast; // Right of last node refers to the first // node of the List rightLast->right = leftList; return leftList; } // Function converts a tree to a circular Linked List // and then returns the head of the Linked List Node* bTreeToCList(Node* root) { if (root == NULL) return NULL; // Recursively convert left and right subtrees Node* left = bTreeToCList(root->left); Node* right = bTreeToCList(root->right); // Make a circular linked list of single node // (or root). To do so, make the right and // left pointers of this node point to itself root->left = root->right = root; // Step 1 (concatenate the left list with the list // with single node, i.e., current node) // Step 2 (concatenate the returned list with the // right List) return concatenate(concatenate(left, root), right); } // Display Circular Link List void displayCList(Node* head) { cout << "Circular Linked List is :\n"; Node* itr = head; do { cout << itr->data << " "; itr = itr->right; } while (head != itr); cout << "\n"; } // Create a new Node and return its address Node* newNode(int data) { Node* temp = new Node(); temp->data = data; temp->left = temp->right = NULL; return temp; } // Driver Program to test above function int main() { Node* root = newNode(10); root->left = newNode(12); root->right = newNode(15); root->left->left = newNode(25); root->left->right = newNode(30); root->right->left = newNode(36); Node* head = bTreeToCList(root); displayCList(head); return 0; } // This code is contributed by Aditya Kumar (adityakumar129)
logn
linear
// A C++ program for in-place conversion of Binary Tree to // CDLL #include <iostream> using namespace std; /* A binary tree node has - data , left and right pointers */ struct Node { int data; Node* left; Node* right; }; // A utility function that converts given binary tree to // a doubly linked list // root --> the root of the binary tree // head --> head of the created doubly linked list Node* BTree2DoublyLinkedList(Node* root, Node** head) { // Base case if (root == NULL) return root; // Initialize previously visited node as NULL. This is // static so that the same value is accessible in all // recursive calls static Node* prev = NULL; // Recursively convert left subtree BTree2DoublyLinkedList(root->left, head); // Now convert this node if (prev == NULL) *head = root; else { root->left = prev; prev->right = root; } prev = root; // Finally convert right subtree BTree2DoublyLinkedList(root->right, head); return prev; } // A simple recursive function to convert a given Binary // tree to Circular Doubly Linked List using a utility // function root --> Root of Binary Tree tail --> Pointer to // tail node of created circular doubly linked list Node* BTree2CircularDoublyLinkedList(Node* root) { Node* head = NULL; Node* tail = BTree2DoublyLinkedList(root, &head); // make the changes to convert a DLL to CDLL tail->right = head; head->left = tail; // return the head of the created CDLL return head; } /* Helper function that allocates a new node with the given data and NULL left and right pointers. */ Node* newNode(int data) { Node* new_node = new Node; new_node->data = data; new_node->left = new_node->right = NULL; return (new_node); } /* Function to print nodes in a given circular doubly linked * list */ void printList(Node* head) { if (head == NULL) return; Node* ptr = head; do { cout << ptr->data << " "; ptr = ptr->right; } while (ptr != head); } /* Driver program to test above functions*/ int main() { // Let us create the tree shown in above diagram Node* root = newNode(10); root->left = newNode(12); root->right = newNode(15); root->left->left = newNode(25); root->left->right = newNode(30); root->right->left = newNode(36); // Convert to DLL Node* head = BTree2CircularDoublyLinkedList(root); // Print the converted list printList(head); return 0; } // This code was contributed by Abhijeet // Kumar(abhijeet19403)
logn
linear
// C++ program to convert a ternary expression to // a tree. #include<bits/stdc++.h> using namespace std; // tree structure struct Node { char data; Node *left, *right; }; // function create a new node Node *newNode(char Data) { Node *new_node = new Node; new_node->data = Data; new_node->left = new_node->right = NULL; return new_node; } // Function to convert Ternary Expression to a Binary // Tree. It return the root of tree // Notice that we pass index i by reference because we // want to skip the characters in the subtree Node *convertExpression(string str, int & i) { // store current character of expression_string // [ 'a' to 'z'] Node * root =newNode(str[i]); //If it was last character return //Base Case if(i==str.length()-1) return root; // Move ahead in str i++; //If the next character is '?'.Then there will be subtree for the current node if(str[i]=='?') { //skip the '?' i++; // construct the left subtree // Notice after the below recursive call i will point to ':' // just before the right child of current node since we pass i by reference root->left = convertExpression(str,i); //skip the ':' character i++; //construct the right subtree root->right = convertExpression(str,i); return root; } //If the next character is not '?' no subtree just return it else return root; } // function print tree void printTree( Node *root) { if (!root) return ; cout << root->data <<" "; printTree(root->left); printTree(root->right); } // Driver program to test above function int main() { string expression = "a?b?c:d:e"; int i=0; Node *root = convertExpression(expression, i); printTree(root) ; return 0; }
linear
linear
// C++ program for Minimum swap required // to convert binary tree to binary search tree #include<bits/stdc++.h> using namespace std; // Inorder Traversal of Binary Tree void inorder(int a[], std::vector<int> &v, int n, int index) { // if index is greater or equal to vector size if(index >= n) return; inorder(a, v, n, 2 * index + 1); // push elements in vector v.push_back(a[index]); inorder(a, v, n, 2 * index + 2); } // Function to find minimum swaps to sort an array int minSwaps(std::vector<int> &v) { std::vector<pair<int,int> > t(v.size()); int ans = 0; for(int i = 0; i < v.size(); i++) t[i].first = v[i], t[i].second = i; sort(t.begin(), t.end()); for(int i = 0; i < t.size(); i++) { // second element is equal to i if(i == t[i].second) continue; else { // swapping of elements swap(t[i].first, t[t[i].second].first); swap(t[i].second, t[t[i].second].second); } // Second is not equal to i if(i != t[i].second) --i; ans++; } return ans; } // Driver code int main() { int a[] = { 5, 6, 7, 8, 9, 10, 11 }; int n = sizeof(a) / sizeof(a[0]); std::vector<int> v; inorder(a, v, n, 0); cout << minSwaps(v) << endl; } // This code is contributed by code_freak
linear
nlogn
/* Program to check children sum property */ #include <bits/stdc++.h> using namespace std; /* A binary tree node has data, left child and right child */ struct node { int data; struct node* left; struct node* right; }; /* returns 1 if children sum property holds for the given node and both of its children*/ int isSumProperty(struct node* node) { /* left_data is left child data and right_data is for right child data*/ int sum = 0; /* If node is NULL or it's a leaf node then return true */ if (node == NULL || (node->left == NULL && node->right == NULL)) return 1; else { /* If left child is not present then 0 is used as data of left child */ if (node->left != NULL) sum += node->left->data; /* If right child is not present then 0 is used as data of right child */ if (node->right != NULL) sum += node->right->data; /* if the node and both of its children satisfy the property return 1 else 0*/ return ((node->data == sum) && isSumProperty(node->left) && isSumProperty(node->right)); } } /* Helper function that allocates a new node with the given data and NULL left and right pointers. */ struct node* newNode(int data) { struct node* node = (struct node*)malloc(sizeof(struct node)); node->data = data; node->left = NULL; node->right = NULL; return (node); } // Driver Code int main() { struct node* root = newNode(10); root->left = newNode(8); root->right = newNode(2); root->left->left = newNode(3); root->left->right = newNode(5); root->right->right = newNode(2); // Function call if (isSumProperty(root)) cout << "The given tree satisfies " << "the children sum property "; else cout << "The given tree does not satisfy " << "the children sum property "; getchar(); return 0; } // This code is contributed by Akanksha Rai
logn
linear
// C++ program to check if two Nodes in a binary tree are // cousins #include <bits/stdc++.h> using namespace std; // A Binary Tree Node struct Node { int data; struct Node *left, *right; }; // A utility function to create a new Binary Tree Node struct Node* newNode(int item) { struct Node* temp = new Node; temp->data = item; temp->left = temp->right = NULL; return temp; } // Recursive function to check if two Nodes are siblings int isSibling(struct Node* root, struct Node* a, struct Node* b) { // Base case if (root == NULL) return 0; return ((root->left == a && root->right == b) || (root->left == b && root->right == a) || isSibling(root->left, a, b) || isSibling(root->right, a, b)); } // Recursive function to find level of Node 'ptr' in a // binary tree int level(struct Node* root, struct Node* ptr, int lev) { // base cases if (root == NULL) return 0; if (root == ptr) return lev; // Return level if Node is present in left subtree int l = level(root->left, ptr, lev + 1); if (l != 0) return l; // Else search in right subtree return level(root->right, ptr, lev + 1); } // Returns 1 if a and b are cousins, otherwise 0 int isCousin(struct Node* root, struct Node* a, struct Node* b) { // 1. The two Nodes should be on the same level in the // binary tree. // 2. The two Nodes should not be siblings (means that // they should // not have the same parent Node). if ((level(root, a, 1) == level(root, b, 1)) && !(isSibling(root, a, b))) return 1; else return 0; } // Driver Program to test above functions int main() { struct Node* root = newNode(1); root->left = newNode(2); root->right = newNode(3); root->left->left = newNode(4); root->left->right = newNode(5); root->left->right->right = newNode(15); root->right->left = newNode(6); root->right->right = newNode(7); root->right->left->right = newNode(8); struct Node *Node1, *Node2; Node1 = root->left->left; Node2 = root->right->right; if (isCousin(root, Node1, Node2)) printf("Yes\n"); else printf("No\n"); return 0; } // This code is contributed by ajaymakwana
linear
linear
// C++ program to check if all leaves // are at same level #include <bits/stdc++.h> using namespace std; // A binary tree node struct Node { int data; struct Node *left, *right; }; // A utility function to allocate // a new tree node struct Node* newNode(int data) { struct Node* node = (struct Node*) malloc(sizeof(struct Node)); node->data = data; node->left = node->right = NULL; return node; } /* Recursive function which checks whether all leaves are at same level */ bool checkUtil(struct Node *root, int level, int *leafLevel) { // Base case if (root == NULL) return true; // If a leaf node is encountered if (root->left == NULL && root->right == NULL) { // When a leaf node is found // first time if (*leafLevel == 0) { *leafLevel = level; // Set first found leaf's level return true; } // If this is not first leaf node, compare // its level with first leaf's level return (level == *leafLevel); } // If this node is not leaf, recursively // check left and right subtrees return checkUtil(root->left, level + 1, leafLevel) && checkUtil(root->right, level + 1, leafLevel); } /* The main function to check if all leafs are at same level. It mainly uses checkUtil() */ bool check(struct Node *root) { int level = 0, leafLevel = 0; return checkUtil(root, level, &leafLevel); } // Driver Code int main() { // Let us create tree shown in third example struct Node *root = newNode(12); root->left = newNode(5); root->left->left = newNode(3); root->left->right = newNode(9); root->left->left->left = newNode(1); root->left->right->left = newNode(1); if (check(root)) cout << "Leaves are at same level\n"; else cout << "Leaves are not at same level\n"; getchar(); return 0; } // This code is contributed // by Akanksha Rai
linear
linear
// C++ program to check if all leaf nodes are at // same level of binary tree #include <bits/stdc++.h> using namespace std; // tree node struct Node { int data; Node *left, *right; }; // returns a new tree Node Node* newNode(int data) { Node* temp = new Node(); temp->data = data; temp->left = temp->right = NULL; return temp; } // return true if all leaf nodes are // at same level, else false int checkLevelLeafNode(Node* root) { if (!root) return 1; // create a queue for level order traversal queue<Node*> q; q.push(root); int result = INT_MAX; int level = 0; // traverse until the queue is empty while (!q.empty()) { int size = q.size(); level += 1; // traverse for complete level while(size > 0){ Node* temp = q.front(); q.pop(); // check for left child if (temp->left) { q.push(temp->left); // if its leaf node if(!temp->left->right && !temp->left->left){ // if it's first leaf node, then update result if (result == INT_MAX) result = level; // if it's not first leaf node, then compare // the level with level of previous leaf node else if (result != level) return 0; } } // check for right child if (temp->right){ q.push(temp->right); // if it's leaf node if (!temp->right->left && !temp->right->right) // if it's first leaf node till now, // then update the result if (result == INT_MAX) result = level; // if it is not the first leaf node, // then compare the level with level // of previous leaf node else if(result != level) return 0; } size -= 1; } } return 1; } // driver program int main() { // construct a tree Node* root = newNode(1); root->left = newNode(2); root->right = newNode(3); root->left->right = newNode(4); root->right->left = newNode(5); root->right->right = newNode(6); int result = checkLevelLeafNode(root); if (result) cout << "All leaf nodes are at same level\n"; else cout << "Leaf nodes not at same level\n"; return 0; }
linear
linear
// C++ program to check if there exist an edge whose // removal creates two trees of same size #include<bits/stdc++.h> using namespace std; struct Node { int data; struct Node* left, *right; }; // utility function to create a new node struct Node* newNode(int x) { struct Node* temp = new Node; temp->data = x; temp->left = temp->right = NULL; return temp; }; // To calculate size of tree with given root int count(Node* root) { if (root==NULL) return 0; return count(root->left) + count(root->right) + 1; } // This function returns true if there is an edge // whose removal can divide the tree in two halves // n is size of tree bool checkRec(Node* root, int n) { // Base cases if (root ==NULL) return false; // Check for root if (count(root) == n-count(root)) return true; // Check for rest of the nodes return checkRec(root->left, n) || checkRec(root->right, n); } // This function mainly uses checkRec() bool check(Node *root) { // Count total nodes in given tree int n = count(root); // Now recursively check all nodes return checkRec(root, n); } // Driver code int main() { struct Node* root = newNode(5); root->left = newNode(1); root->right = newNode(6); root->left->left = newNode(3); root->right->left = newNode(7); root->right->right = newNode(4); check(root)? printf("YES") : printf("NO"); return 0; }
linear
quadratic
// C++ program to check if there exist an edge whose // removal creates two trees of same size #include<bits/stdc++.h> using namespace std; struct Node { int data; struct Node* left, *right; }; // utility function to create a new node struct Node* newNode(int x) { struct Node* temp = new Node; temp->data = x; temp->left = temp->right = NULL; return temp; }; // To calculate size of tree with given root int count(Node* root) { if (root==NULL) return 0; return count(root->left) + count(root->right) + 1; } // This function returns size of tree rooted with given // root. It also set "res" as true if there is an edge // whose removal divides tree in two halves. // n is size of tree int checkRec(Node* root, int n, bool &res) { // Base case if (root == NULL) return 0; // Compute sizes of left and right children int c = checkRec(root->left, n, res) + 1 + checkRec(root->right, n, res); // If required property is true for current node // set "res" as true if (c == n-c) res = true; // Return size return c; } // This function mainly uses checkRec() bool check(Node *root) { // Count total nodes in given tree int n = count(root); // Initialize result and recursively check all nodes bool res = false; checkRec(root, n, res); return res; } // Driver code int main() { struct Node* root = newNode(5); root->left = newNode(1); root->right = newNode(6); root->left->left = newNode(3); root->right->left = newNode(7); root->right->right = newNode(4); check(root)? printf("YES") : printf("NO"); return 0; }
linear
linear
/* C++ program to check if all three given traversals are of the same tree */ #include <bits/stdc++.h> using namespace std; // A Binary Tree Node struct Node { int data; struct Node *left, *right; }; // Utility function to create a new tree node Node* newNode(int data) { Node *temp = new Node; temp->data = data; temp->left = temp->right = NULL; return temp; } /* Function to find index of value in arr[start...end] The function assumes that value is present in in[] */ int search(int arr[], int strt, int end, int value) { for (int i = strt; i <= end; i++) { if(arr[i] == value) return i; } } /* Recursive function to construct binary tree of size len from Inorder traversal in[] and Preorder traversal pre[]. Initial values of inStrt and inEnd should be 0 and len -1. The function doesn't do any error checking for cases where inorder and preorder do not form a tree */ Node* buildTree(int in[], int pre[], int inStrt, int inEnd) { static int preIndex = 0; if(inStrt > inEnd) return NULL; /* Pick current node from Preorder traversal using preIndex and increment preIndex */ Node *tNode = newNode(pre[preIndex++]); /* If this node has no children then return */ if (inStrt == inEnd) return tNode; /* Else find the index of this node in Inorder traversal */ int inIndex = search(in, inStrt, inEnd, tNode->data); /* Using index in Inorder traversal, construct left and right subtress */ tNode->left = buildTree(in, pre, inStrt, inIndex-1); tNode->right = buildTree(in, pre, inIndex+1, inEnd); return tNode; } /* function to compare Postorder traversal on constructed tree and given Postorder */ int checkPostorder(Node* node, int postOrder[], int index) { if (node == NULL) return index; /* first recur on left child */ index = checkPostorder(node->left,postOrder,index); /* now recur on right child */ index = checkPostorder(node->right,postOrder,index); /* Compare if data at current index in both Postorder traversals are same */ if (node->data == postOrder[index]) index++; else return -1; return index; } // Driver program to test above functions int main() { int inOrder[] = {4, 2, 5, 1, 3}; int preOrder[] = {1, 2, 4, 5, 3}; int postOrder[] = {4, 5, 2, 3, 1}; int len = sizeof(inOrder)/sizeof(inOrder[0]); // build tree from given // Inorder and Preorder traversals Node *root = buildTree(inOrder, preOrder, 0, len - 1); // compare postorder traversal on constructed // tree with given Postorder traversal int index = checkPostorder(root,postOrder,0); // If both postorder traversals are same if (index == len) cout << "Yes"; else cout << "No"; return 0; }
linear
quadratic
#include <bits/stdc++.h> using namespace std; struct Node { int data; Node *left, *right; Node(int val) { data = val; left = right = NULL; } }; Node* buildTreeFromInorderPreorder( int inStart, int inEnd, int& preIndex, int preorder[], unordered_map<int, int>& inorderIndexMap, bool& notPossible) { if (inStart > inEnd) return NULL; // build the current Node int rootData = preorder[preIndex]; Node* root = new Node(rootData); preIndex++; // find the node in inorderIndexMap if (inorderIndexMap.find(rootData) == inorderIndexMap.end()) { notPossible = true; return root; } int inorderIndex = inorderIndexMap[rootData]; if (!(inStart <= inorderIndex && inorderIndex <= inEnd)) { notPossible = true; return root; } int leftInorderStart = inStart, leftInorderEnd = inorderIndex - 1, rightInorderStart = inorderIndex + 1, rightInorderEnd = inEnd; root->left = buildTreeFromInorderPreorder( leftInorderStart, leftInorderEnd, preIndex, preorder, inorderIndexMap, notPossible); if (notPossible) return root; root->right = buildTreeFromInorderPreorder( rightInorderStart, rightInorderEnd, preIndex, preorder, inorderIndexMap, notPossible); return root; } bool checkPostorderCorrect(Node* root, int& postIndex, int postorder[]) { if (!root) return true; if (!checkPostorderCorrect(root->left, postIndex, postorder)) return false; if (!checkPostorderCorrect(root->right, postIndex, postorder)) return false; return (root->data == postorder[postIndex++]); } void printPostorder(Node* root) { if (!root) return; printPostorder(root->left); printPostorder(root->right); cout << root->data << ", "; } void printInorder(Node* root) { if (!root) return; printInorder(root->left); cout << root->data << ", "; printInorder(root->right); } bool checktree(int preorder[], int inorder[], int postorder[], int N) { // Your code goes here if (N == 0) return true; unordered_map<int, int> inorderIndexMap; for (int i = 0; i < N; i++) inorderIndexMap[inorder[i]] = i; int preIndex = 0; // return checkInorderPreorder(0, N - 1, preIndex, // preorder, inorderIndexMap) && // checkInorderPostorder(0, N - 1, postIndex, postorder, // inorderIndexMap); bool notPossible = false; Node* root = buildTreeFromInorderPreorder( 0, N - 1, preIndex, preorder, inorderIndexMap, notPossible); if (notPossible) return false; int postIndex = 0; return checkPostorderCorrect(root, postIndex, postorder); } // Driver program to test above functions int main() { int inOrder[] = { 4, 2, 5, 1, 3 }; int preOrder[] = { 1, 2, 4, 5, 3 }; int postOrder[] = { 4, 5, 2, 3, 1 }; int len = sizeof(inOrder) / sizeof(inOrder[0]); // If both postorder traversals are same if (checktree(preOrder, inOrder, postOrder, len)) cout << "Yes"; else cout << "No"; return 0; }
linear
linear
// C++ code to check if leaf traversals // of two Binary Trees are same or not. #include <bits/stdc++.h> using namespace std; // Binary Tree Node struct Node { int data; Node* left; Node* right; }; // Returns new Node with data as // input to below function. Node* newNode(int d) { Node* temp = new Node; temp->data = d; temp->left = NULL; temp->right = NULL; return temp; } // checks if a given node is leaf or not. bool isLeaf(Node* root) { if (root == NULL) return false; if (!root->left && !root->right) return true; return false; } // iterative function. // returns true if leaf traversals // are same, else false. bool isSame(Node* root1, Node* root2) { stack<Node*> s1; stack<Node*> s2; // push root1 to empty stack s1. s1.push(root1); // push root2 to empty stack s2. s2.push(root2); // loop until either of stacks are non-empty. while (!s1.empty() || !s2.empty()) { // this means one of the stacks has // extra leaves, hence return false. if (s1.empty() || s2.empty()) return false; Node* temp1 = s1.top(); s1.pop(); while (temp1 != NULL && !isLeaf(temp1)) { // Push right child if exists if (temp1->right) s1.push(temp1->right); // Push left child if exists if (temp1->left) s1.push(temp1->left); // Note that right child(if exists) // is pushed before left child(if exists). temp1 = s1.top(); s1.pop(); } Node* temp2 = s2.top(); s2.pop(); while (temp2 != NULL && !isLeaf(temp2)) { // Push right child if exists if (temp2->right) s2.push(temp2->right); // Push left child if exists if (temp2->left) s2.push(temp2->left); temp2 = s2.top(); s2.pop(); } if (!temp1 && temp2 || temp1 && !temp2) return false; if (temp1 && temp2 && temp1->data!=temp2->data) { return false; } } // all leaves are matched return true; } // Driver Code int main() { Node* root1 = newNode(1); root1->left = newNode(2); root1->right = newNode(3); root1->left->left = newNode(4); root1->right->left = newNode(6); root1->right->right = newNode(7); Node* root2 = newNode(0); root2->left = newNode(1); root2->right = newNode(5); root2->left->right = newNode(4); root2->right->left = newNode(6); root2->right->right = newNode(7); if (isSame(root1, root2)) cout << "Same"; else cout << "Not Same"; return 0; } // This code is contributed // by AASTHA VARMA
nlogn
linear
// C++ program to check whether a given Binary Tree is full or not #include <bits/stdc++.h> using namespace std; /* Tree node structure */ struct Node { int key; struct Node *left, *right; }; /* Helper function that allocates a new node with the given key and NULL left and right pointer. */ struct Node *newNode(char k) { struct Node *node = new Node; node->key = k; node->right = node->left = NULL; return node; } /* This function tests if a binary tree is a full binary tree. */ bool isFullTree (struct Node* root) { // If empty tree if (root == NULL) return true; // If leaf node if (root->left == NULL && root->right == NULL) return true; // If both left and right are not NULL, and left & right subtrees // are full if ((root->left) && (root->right)) return (isFullTree(root->left) && isFullTree(root->right)); // We reach here when none of the above if conditions work return false; } // Driver Program int main() { struct Node* root = NULL; root = newNode(10); root->left = newNode(20); root->right = newNode(30); root->left->right = newNode(40); root->left->left = newNode(50); root->right->left = newNode(60); root->right->right = newNode(70); root->left->left->left = newNode(80); root->left->left->right = newNode(90); root->left->right->left = newNode(80); root->left->right->right = newNode(90); root->right->left->left = newNode(80); root->right->left->right = newNode(90); root->right->right->left = newNode(80); root->right->right->right = newNode(90); if (isFullTree(root)) cout << "The Binary Tree is full\n"; else cout << "The Binary Tree is not full\n"; return(0); } // This code is contributed by shubhamsingh10
linear
linear
// c++ program to check whether a given BT is full or not #include <bits/stdc++.h> using namespace std; // Tree node structure struct Node { int val; Node *left, *right; }; // fun that creates and returns a new node Node* newNode(int data) { Node* node = new Node(); node->val = data; node->left = node->right = NULL; return node; } // helper fun to check leafnode bool isleafnode(Node* root) { return !root->left && !root->right; } // fun checks whether the given BT is a full BT or not bool isFullTree(Node* root) { // if tree is empty if (!root) return true; queue<Node*> q; q.push(root); while (!q.empty()) { root = q.front(); q.pop(); // null indicates - not a full BT if (root == NULL) return false; // if its not a leafnode then the current node // should contain both left and right pointers. if (!isleafnode(root)) { q.push(root->left); q.push(root->right); } } return true; } int main() { Node* root = newNode(1); root->left = newNode(2); root->right = newNode(3); root->left->left = newNode(4); root->left->right = newNode(5); if (isFullTree(root)) cout << "The Binary Tree is full\n"; else cout << "The Binary Tree is not full\n"; return 0; } // This code is contributed by Modem Upendra.
linear
linear
// C++ implementation to check whether a binary // tree is a full binary tree or not #include <bits/stdc++.h> using namespace std; // structure of a node of binary tree struct Node { int data; Node *left, *right; }; // function to get a new node Node* getNode(int data) { // allocate space Node* newNode = (Node*)malloc(sizeof(Node)); // put in the data newNode->data = data; newNode->left = newNode->right = NULL; return newNode; } // function to check whether a binary tree // is a full binary tree or not bool isFullBinaryTree(Node* root) { // if tree is empty if (!root) return true; // queue used for level order traversal queue<Node*> q; // push 'root' to 'q' q.push(root); // traverse all the nodes of the binary tree // level by level until queue is empty while (!q.empty()) { // get the pointer to 'node' at front // of queue Node* node = q.front(); q.pop(); // if it is a leaf node then continue if (node->left == NULL && node->right == NULL) continue; // if either of the child is not null and the // other one is null, then binary tree is not // a full binary tee if (node->left == NULL || node->right == NULL) return false; // push left and right childs of 'node' // on to the queue 'q' q.push(node->left); q.push(node->right); } // binary tree is a full binary tee return true; } // Driver program to test above int main() { Node* root = getNode(1); root->left = getNode(2); root->right = getNode(3); root->left->left = getNode(4); root->left->right = getNode(5); if (isFullBinaryTree(root)) cout << "Yes"; else cout << "No"; return 0; }
constant
linear
// C++ program to check if a given binary tree is complete // or not #include <bits/stdc++.h> using namespace std; // A binary tree node has data, pointer to left child and a // pointer to right child struct node { int data; struct node* left; struct node* right; }; // Given a binary tree, return true if the tree is complete // else false bool isCompleteBT(node* root) { // Base Case: An empty tree is complete Binary Tree if (root == NULL) return true; // Create an empty queue // int rear, front; // node **queue = createQueue(&front, &rear); queue<node*> q; q.push(root); // Create a flag variable which will be set true when a // non full node is seen bool flag = false; // Do level order traversal using queue. // enQueue(queue, &rear, root); while (!q.empty()) { node* temp = q.front(); q.pop(); /* Check if left child is present*/ if (temp->left) { // If we have seen a non full node, and we see a // node with non-empty left child, then the // given tree is not a complete Binary Tree if (flag == true) return false; q.push(temp->left); // Enqueue Left Child } // If this a non-full node, set the flag as true else flag = true; /* Check if right child is present*/ if (temp->right) { // If we have seen a non full node, and we see a // node with non-empty right child, then the // given tree is not a complete Binary Tree if (flag == true) return false; q.push(temp->right); // Enqueue Right Child } // If this a non-full node, set the flag as true else flag = true; } // If we reach here, then the tree is complete Binary // Tree return true; } /* Helper function that allocates a new node with the given data and NULL left and right pointers. */ struct node* newNode(int data) { struct node* node = (struct node*)malloc(sizeof(struct node)); node->data = data; node->left = NULL; node->right = NULL; return (node); } /* Driver code*/ int main() { /* Let us construct the following Binary Tree which is not a complete Binary Tree 1 / \ 2 3 / \ / 4 5 6 */ node* root = newNode(1); root->left = newNode(2); root->right = newNode(3); root->left->left = newNode(4); root->left->right = newNode(5); root->right->left = newNode(6); if (isCompleteBT(root) == true) cout << "Complete Binary Tree"; else cout << "NOT Complete Binary Tree"; return 0; } // This code is contributed by Sania Kumari Gupta (kriSania804)
linear
linear
/* Program to check if a given Binary Tree is balanced like a Red-Black Tree */ #include <bits/stdc++.h> using namespace std; struct Node { int key; Node *left, *right; }; /* utility that allocates a new Node with the given key */ Node* newNode(int key) { Node* node = new Node; node->key = key; node->left = node->right = NULL; return (node); } // Returns returns tree if the Binary tree is balanced like a Red-Black // tree. This function also sets value in maxh and minh (passed by // reference). maxh and minh are set as maximum and minimum heights of root. bool isBalancedUtil(Node *root, int &maxh, int &minh) { // Base case if (root == NULL) { maxh = minh = 0; return true; } int lmxh, lmnh; // To store max and min heights of left subtree int rmxh, rmnh; // To store max and min heights of right subtree // Check if left subtree is balanced, also set lmxh and lmnh if (isBalancedUtil(root->left, lmxh, lmnh) == false) return false; // Check if right subtree is balanced, also set rmxh and rmnh if (isBalancedUtil(root->right, rmxh, rmnh) == false) return false; // Set the max and min heights of this node for the parent call maxh = max(lmxh, rmxh) + 1; minh = min(lmnh, rmnh) + 1; // See if this node is balanced if (maxh <= 2*minh) return true; return false; } // A wrapper over isBalancedUtil() bool isBalanced(Node *root) { int maxh, minh; return isBalancedUtil(root, maxh, minh); } /* Driver program to test above functions*/ int main() { Node * root = newNode(10); root->left = newNode(5); root->right = newNode(100); root->right->left = newNode(50); root->right->right = newNode(150); root->right->left->left = newNode(40); isBalanced(root)? cout << "Balanced" : cout << "Not Balanced"; return 0; }
linear
linear
// C++ program to check if two trees are mirror // of each other #include<bits/stdc++.h> using namespace std; /* A binary tree node has data, pointer to left child and a pointer to right child */ struct Node { int data; Node* left, *right; }; /* Given two trees, return true if they are mirror of each other */ /*As function has to return bool value instead integer value*/ bool areMirror(Node* a, Node* b) { /* Base case : Both empty */ if (a==NULL && b==NULL) return true; // If only one is empty if (a==NULL || b == NULL) return false; /* Both non-empty, compare them recursively Note that in recursive calls, we pass left of one tree and right of other tree */ return a->data == b->data && areMirror(a->left, b->right) && areMirror(a->right, b->left); } /* Helper function that allocates a new node */ Node* newNode(int data) { Node* node = new Node; node->data = data; node->left = node->right = NULL; return(node); } /* Driver program to test areMirror() */ int main() { Node *a = newNode(1); Node *b = newNode(1); a->left = newNode(2); a->right = newNode(3); a->left->left = newNode(4); a->left->right = newNode(5); b->left = newNode(3); b->right = newNode(2); b->right->left = newNode(5); b->right->right = newNode(4); areMirror(a, b)? cout << "Yes" : cout << "No"; return 0; }
logn
linear
// C++ implementation to check whether the two // binary trees are mirrors of each other or not #include <bits/stdc++.h> using namespace std; // structure of a node in binary tree struct Node { int data; struct Node *left, *right; }; // Utility function to create and return // a new node for a binary tree struct Node* newNode(int data) { struct Node *temp = new Node(); temp->data = data; temp->left = temp->right = NULL; return temp; } // function to check whether the two binary trees // are mirrors of each other or not string areMirrors(Node *root1, Node *root2) { stack<Node*> st1, st2; while (1) { // iterative inorder traversal of 1st tree and // reverse inorder traversal of 2nd tree while (root1 && root2) { // if the corresponding nodes in the two traversal // have different data values, then they are not // mirrors of each other. if (root1->data != root2->data) return "No"; st1.push(root1); st2.push(root2); root1 = root1->left; root2 = root2->right; } // if at any point one root becomes null and // the other root is not null, then they are // not mirrors. This condition verifies that // structures of tree are mirrors of each other. if (!(root1 == NULL && root2 == NULL)) return "No"; if (!st1.empty() && !st2.empty()) { root1 = st1.top(); root2 = st2.top(); st1.pop(); st2.pop(); /* we have visited the node and its left subtree. Now, it's right subtree's turn */ root1 = root1->right; /* we have visited the node and its right subtree. Now, it's left subtree's turn */ root2 = root2->left; } // both the trees have been completely traversed else break; } // trees are mirrors of each other return "Yes"; } // Driver program to test above int main() { // 1st binary tree formation Node *root1 = newNode(1); /* 1 */ root1->left = newNode(3); /* / \ */ root1->right = newNode(2); /* 3 2 */ root1->right->left = newNode(5); /* / \ */ root1->right->right = newNode(4); /* 5 4 */ // 2nd binary tree formation Node *root2 = newNode(1); /* 1 */ root2->left = newNode(2); /* / \ */ root2->right = newNode(3); /* 2 3 */ root2->left->left = newNode(4); /* / \ */ root2->left->right = newNode(5); /* 4 5 */ cout << areMirrors(root1, root2); return 0; }
linear
linear
// C++ program to check if a given Binary // Tree is symmetric or not #include<bits/stdc++.h> using namespace std; // A Binary Tree Node struct Node { int key; struct Node* left, *right; }; // Utility function to create new Node Node *newNode(int key) { Node *temp = new Node; temp->key = key; temp->left = temp->right = NULL; return (temp); } // Returns true if a tree is symmetric // i.e. mirror image of itself bool isSymmetric(struct Node* root) { if(root == NULL) return true; // If it is a single tree node, then // it is a symmetric tree. if(!root->left && !root->right) return true; queue <Node*> q; // Add root to queue two times so that // it can be checked if either one child // alone is NULL or not. q.push(root); q.push(root); // To store two nodes for checking their // symmetry. Node* leftNode, *rightNode; while(!q.empty()){ // Remove first two nodes to check // their symmetry. leftNode = q.front(); q.pop(); rightNode = q.front(); q.pop(); // if both left and right nodes // exist, but have different // values--> inequality, return false if(leftNode->key != rightNode->key){ return false; } // Push left child of left subtree node // and right child of right subtree // node in queue. if(leftNode->left && rightNode->right){ q.push(leftNode->left); q.push(rightNode->right); } // If only one child is present alone // and other is NULL, then tree // is not symmetric. else if (leftNode->left || rightNode->right) return false; // Push right child of left subtree node // and left child of right subtree node // in queue. if(leftNode->right && rightNode->left){ q.push(leftNode->right); q.push(rightNode->left); } // If only one child is present alone // and other is NULL, then tree // is not symmetric. else if(leftNode->right || rightNode->left) return false; } return true; } // Driver program int main() { // Let us construct the Tree shown in // the above figure Node *root = newNode(1); root->left = newNode(2); root->right = newNode(2); root->left->left = newNode(3); root->left->right = newNode(4); root->right->left = newNode(4); root->right->right = newNode(3); if(isSymmetric(root)) cout << "The given tree is Symmetric"; else cout << "The given tree is not Symmetric"; return 0; } // This code is contributed by Nikhil jindal.
logn
linear
#include <bits/stdc++.h> using namespace std; /* A binary tree node has key, pointer to left child and a pointer to right child */ struct Node { int key; struct Node *left, *right; }; /* To create a newNode of tree and return pointer */ struct Node* newNode(int key) { Node* temp = new Node; temp->key = key; temp->left = temp->right = NULL; return (temp); } // Takes two parameters - same initially and // calls recursively void printMiddleLevelUtil(Node* a, Node* b) { // Base case e if (a == NULL || b == NULL) return; // Fast pointer has reached the leaf so print // value at slow pointer if ((b->left == NULL) && (b->right == NULL)) { cout << a->key << " "; return; } // Recursive call // root.left.left and root.left.right will // print same value // root.right.left and root.right.right // will print same value // So we use any one of the condition if (b->left->left) { printMiddleLevelUtil(a->left, b->left->left); printMiddleLevelUtil(a->right, b->left->left); } else { printMiddleLevelUtil(a->left, b->left); printMiddleLevelUtil(a->right, b->left); } } // Main printing method that take a Tree as input void printMiddleLevel(Node* node) { printMiddleLevelUtil(node, node); } // Driver program to test above functions int main() { Node* n1 = newNode(1); Node* n2 = newNode(2); Node* n3 = newNode(3); Node* n4 = newNode(4); Node* n5 = newNode(5); Node* n6 = newNode(6); Node* n7 = newNode(7); n2->left = n4; n2->right = n5; n3->left = n6; n3->right = n7; n1->left = n2; n1->right = n3; printMiddleLevel(n1); } // This code is contributed by Prasad Kshirsagar
logn
linear
// C++ program to Print root to leaf path WITHOUT // using recursion #include <bits/stdc++.h> using namespace std; /* A binary tree */ struct Node { int data; struct Node *left, *right; }; /* Helper function that allocates a new node with the given data and NULL left and right pointers.*/ Node* newNode(int data) { Node* node = new Node; node->data = data; node->left = node->right = NULL; return node; } /* Function to print root to leaf path for a leaf using parent nodes stored in map */ void printTopToBottomPath(Node* curr, map<Node*, Node*> parent) { stack<Node*> stk; // start from leaf node and keep on pushing // nodes into stack till root node is reached while (curr) { stk.push(curr); curr = parent[curr]; } // Start popping nodes from stack and print them while (!stk.empty()) { curr = stk.top(); stk.pop(); cout << curr->data << " "; } cout << endl; } /* An iterative function to do preorder traversal of binary tree and print root to leaf path without using recursion */ void printRootToLeaf(Node* root) { // Corner Case if (root == NULL) return; // Create an empty stack and push root to it stack<Node*> nodeStack; nodeStack.push(root); // Create a map to store parent pointers of binary // tree nodes map<Node*, Node*> parent; // parent of root is NULL parent[root] = NULL; /* Pop all items one by one. Do following for every popped item a) push its right child and set its parent pointer b) push its left child and set its parent pointer Note that right child is pushed first so that left is processed first */ while (!nodeStack.empty()) { // Pop the top item from stack Node* current = nodeStack.top(); nodeStack.pop(); // If leaf node encountered, print Top To // Bottom path if (!(current->left) && !(current->right)) printTopToBottomPath(current, parent); // Push right & left children of the popped node // to stack. Also set their parent pointer in // the map if (current->right) { parent[current->right] = current; nodeStack.push(current->right); } if (current->left) { parent[current->left] = current; nodeStack.push(current->left); } } } // Driver program to test above functions int main() { /* Constructed binary tree is 10 / \ 8 2 / \ / 3 5 2 */ Node* root = newNode(10); root->left = newNode(8); root->right = newNode(2); root->left->left = newNode(3); root->left->right = newNode(5); root->right->left = newNode(2); printRootToLeaf(root); return 0; }
linear
nlogn
// C++ program to print root to leaf path without using // recursion #include <bits/stdc++.h> using namespace std; // A binary tree node structure struct Node { int data; Node *left, *right; }; // fun to create a new node Node* newNode(int data) { Node* temp = new Node(); temp->data = data; temp->left = temp->right = NULL; return temp; } // fun to check leaf node bool isleafnode(Node* root) { return !root->left && !root->right; } // fun to print root to leaf paths without using parent // pointers void printRootToLeaf(Node* root) { // base case if (!root) return; string path = ""; // create an empty stack to store a pair of tree nodes // and its path from root node. stack<pair<Node*, string> > s; // push the root node s.push({ root, path }); // loop untill stack becomes empty while (!s.empty()) { auto it = s.top(); s.pop(); root = it.first; path = it.second; // convert the curr root value to string string curr = to_string(root->data) + " "; // add the current node to the existing path path += curr; // print the path if a node is encountered if (isleafnode(root)) cout << path << endl; if (root->right) s.push({ root->right, path }); if (root->left) s.push({ root->left, path }); } } int main() { // create a tree Node* root = newNode(10); root->left = newNode(8); root->right = newNode(2); root->left->left = newNode(3); root->left->right = newNode(5); root->right->left = newNode(2); printRootToLeaf(root); return 0; } // This code is contributed by Modem Upendra
linear
linear
// C++ program to print all root to leaf paths // with there relative position #include<bits/stdc++.h> using namespace std; #define MAX_PATH_SIZE 1000 // tree structure struct Node { char data; Node *left, *right; }; // function create new node Node * newNode(char data) { struct Node *temp = new Node; temp->data = data; temp->left = temp->right = NULL; return temp; } // store path information struct PATH { int Hd; // horizontal distance of node from root. char key; // store key }; // Prints given root to leaf path with underscores void printPath(vector < PATH > path, int size) { // Find the minimum horizontal distance value // in current root to leaf path int minimum_Hd = INT_MAX; PATH p; // find minimum horizontal distance for (int it=0; it<size; it++) { p = path[it]; minimum_Hd = min(minimum_Hd, p.Hd); } // print the root to leaf path with "_" // that indicate the related position for (int it=0; it < size; it++) { // current tree node p = path[it]; int noOfUnderScores = abs(p.Hd - minimum_Hd); // print underscore for (int i = 0; i < noOfUnderScores; i++) cout << "_ "; // print current key cout << p.key << endl; } cout << "==============================" << endl; } // a utility function print all path from root to leaf // working of this function is similar to function of // "Print_vertical_order" : Print paths of binary tree // in vertical order // https://www.geeksforgeeks.org/print-binary-tree-vertical-order-set-2/ void printAllPathsUtil(Node *root, vector < PATH > &AllPath, int HD, int order ) { // base case if(root == NULL) return; // leaf node if (root->left == NULL && root->right == NULL) { // add leaf node and then print path AllPath[order] = (PATH { HD, root->data }); printPath(AllPath, order+1); return; } // store current path information AllPath[order] = (PATH { HD, root->data }); // call left sub_tree printAllPathsUtil(root->left, AllPath, HD-1, order+1); //call left sub_tree printAllPathsUtil(root->right, AllPath, HD+1, order+1); } void printAllPaths(Node *root) { // base case if (root == NULL) return; vector<PATH> Allpaths(MAX_PATH_SIZE); printAllPathsUtil(root, Allpaths, 0, 0); } // Driver program to test above function int main() { Node *root = newNode('A'); root->left = newNode('B'); root->right = newNode('C'); root->left->left = newNode('D'); root->left->right = newNode('E'); root->right->left = newNode('F'); root->right->right = newNode('G'); printAllPaths(root); return 0; }
logn
constant
// Recursive C++ program to print odd level nodes #include <bits/stdc++.h> using namespace std; struct Node { int data; Node* left, *right; }; void printOddNodes(Node *root, bool isOdd = true) { // If empty tree if (root == NULL) return; // If current node is of odd level if (isOdd) cout << root->data << " " ; // Recur for children with isOdd // switched. printOddNodes(root->left, !isOdd); printOddNodes(root->right, !isOdd); } // Utility method to create a node struct Node* newNode(int data) { struct Node* node = new Node; node->data = data; node->left = node->right = NULL; return (node); } // Driver code int main() { struct Node* root = newNode(1); root->left = newNode(2); root->right = newNode(3); root->left->left = newNode(4); root->left->right = newNode(5); printOddNodes(root); return 0; }
linear
linear
// Iterative C++ program to print odd level nodes #include <bits/stdc++.h> using namespace std; struct Node { int data; Node* left, *right; }; // Iterative method to do level order traversal line by line void printOddNodes(Node *root) { // Base Case if (root == NULL) return; // Create an empty queue for level // order traversal queue<Node *> q; // Enqueue root and initialize level as odd q.push(root); bool isOdd = true; while (1) { // nodeCount (queue size) indicates // number of nodes at current level. int nodeCount = q.size(); if (nodeCount == 0) break; // Dequeue all nodes of current level // and Enqueue all nodes of next level while (nodeCount > 0) { Node *node = q.front(); if (isOdd) cout << node->data << " "; q.pop(); if (node->left != NULL) q.push(node->left); if (node->right != NULL) q.push(node->right); nodeCount--; } isOdd = !isOdd; } } // Utility method to create a node struct Node* newNode(int data) { struct Node* node = new Node; node->data = data; node->left = node->right = NULL; return (node); } // Driver code int main() { struct Node* root = newNode(1); root->left = newNode(2); root->right = newNode(3); root->left->left = newNode(4); root->left->right = newNode(5); printOddNodes(root); return 0; }
linear
linear
// A C++ program to find the all full nodes in // a given binary tree #include <bits/stdc++.h> using namespace std; struct Node { int data; struct Node *left, *right; }; Node *newNode(int data) { Node *temp = new Node; temp->data = data; temp->left = temp->right = NULL; return temp; } // Traverses given tree in Inorder fashion and // prints all nodes that have both children as // non-empty. void findFullNode(Node *root) { if (root != NULL) { findFullNode(root->left); if (root->left != NULL && root->right != NULL) cout << root->data << " "; findFullNode(root->right); } } // Driver program to test above function int main() { Node* root = newNode(1); root->left = newNode(2); root->right = newNode(3); root->left->left = newNode(4); root->right->left = newNode(5); root->right->right = newNode(6); root->right->left->right = newNode(7); root->right->right->right = newNode(8); root->right->left->right->left = newNode(9); findFullNode(root); return 0; }
linear
linear
#include <bits/stdc++.h> #include <iostream> using namespace std; struct Node { int key; struct Node *left, *right; }; // Utility function to create a new node Node* newNode(int key) { Node* temp = new Node; temp->key = key; temp->left = temp->right = NULL; return (temp); } /*Function to find sum of all elements*/ int sumBT(Node* root) { //sum variable to track the sum of //all variables. int sum = 0; queue<Node*> q; //Pushing the first level. q.push(root); //Pushing elements at each level from //the tree. while (!q.empty()) { Node* temp = q.front(); q.pop(); //After popping each element from queue //add its data to the sum variable. sum += temp->key; if (temp->left) { q.push(temp->left); } if (temp->right) { q.push(temp->right); } } return sum; } // Driver program int main() { // Let us create Binary Tree shown in above example Node* root = newNode(1); root->left = newNode(2); root->right = newNode(3); root->left->left = newNode(4); root->left->right = newNode(5); root->right->left = newNode(6); root->right->right = newNode(7); root->right->left->right = newNode(8); cout << "Sum of all elements in the binary tree is: " << sumBT(root); } //This code is contributed by Sarthak Delori
linear
linear
// C++ implementation to find the sum of all // the parent nodes having child node x #include <bits/stdc++.h> using namespace std; // Node of a binary tree struct Node { int data; Node *left, *right; }; // function to get a new node Node* getNode(int data) { // allocate memory for the node Node *newNode = (Node*)malloc(sizeof(Node)); // put in the data newNode->data = data; newNode->left = newNode->right = NULL; return newNode; } // function to find the sum of all the // parent nodes having child node x void sumOfParentOfX(Node* root, int& sum, int x) { // if root == NULL if (!root) return; // if left or right child of root is 'x', then // add the root's data to 'sum' if ((root->left && root->left->data == x) || (root->right && root->right->data == x)) sum += root->data; // recursively find the required parent nodes // in the left and right subtree sumOfParentOfX(root->left, sum, x); sumOfParentOfX(root->right, sum, x); } // utility function to find the sum of all // the parent nodes having child node x int sumOfParentOfXUtil(Node* root, int x) { int sum = 0; sumOfParentOfX(root, sum, x); // required sum of parent nodes return sum; } // Driver program to test above int main() { // binary tree formation Node *root = getNode(4); /* 4 */ root->left = getNode(2); /* / \ */ root->right = getNode(5); /* 2 5 */ root->left->left = getNode(7); /* / \ / \ */ root->left->right = getNode(2); /* 7 2 2 3 */ root->right->left = getNode(2); root->right->right = getNode(3); int x = 2; cout << "Sum = " << sumOfParentOfXUtil(root, x); return 0; }
linear
linear
// CPP program to find total sum // of right leaf nodes #include <bits/stdc++.h> using namespace std; // struct node of binary tree struct Node { int data; Node *left, *right; }; // return new node Node* addNode(int data) { Node* temp = new Node(); temp->data = data; temp->left = temp->right = NULL; return temp; } // utility function to calculate sum // of right leaf nodes void rightLeafSum(Node* root, int& sum) { if (!root) return; // check if the right child of root // is leaf node if (root->right) if (root->right->left == NULL && root->right->right == NULL) sum += root->right->data; rightLeafSum(root->left, sum); rightLeafSum(root->right, sum); } // driver program int main() { // construct binary tree Node* root = addNode(1); root->left = addNode(2); root->left->left = addNode(4); root->left->right = addNode(5); root->left->left->right = addNode(2); root->right = addNode(3); root->right->right = addNode(8); root->right->right->left = addNode(6); root->right->right->right = addNode(7); // variable to store sum of right // leaves int sum = 0; rightLeafSum(root, sum); cout << sum << endl; return 0; }
logn
linear
// C++ program to find total sum of right leaf nodes. #include <bits/stdc++.h> using namespace std; // struct node of Binary Tree struct Node { int data; Node *left, *right; }; // fun to create and return a new node Node* addNode(int data) { Node* temp = new Node(); temp->data = data; temp->left = temp->right = NULL; return temp; } // fun to calculate sum of right leaf nodes int rightLeafSum(Node* root, bool isrightleaf) { // base case if (!root) return 0; // if it is a leaf node and right node, the return // root's data. if (!root->left && !root->right && isrightleaf) return root->data; // recur of left subtree and right subtree and do the // summation simultaniously. return rightLeafSum(root->left, false) + rightLeafSum(root->right, true); } int main() { // create a tree Node* root = addNode(1); root->left = addNode(2); root->left->left = addNode(4); root->left->right = addNode(5); root->left->left->right = addNode(2); root->right = addNode(3); root->right->right = addNode(8); root->right->right->left = addNode(6); root->right->right->right = addNode(7); cout << rightLeafSum(root, false); return 0; } // This code is contributed by Modem Upendra
logn
linear
// CPP program to find total sum // of right leaf nodes #include <bits/stdc++.h> using namespace std; // struct node of binary tree struct Node { int data; Node *left, *right; }; // return new node Node* addNode(int data) { Node* temp = new Node(); temp->data = data; temp->left = temp->right = NULL; return temp; } // utility function to calculate sum // of right leaf nodes iteratively int rightLeafSum(Node* root) { // declaring sum to store sum of right leaves int sum = 0; // queue of Node* type queue<Node*> q; q.push(root); while (!q.empty()) { Node* curr = q.front(); q.pop(); // check for left node if (curr->left) { q.push(curr->left); } // check for right node if (curr->right) { // check for right leaf node if (curr->right->right == NULL and curr->right->left == NULL) { // incrementing sum for found right leaf // node sum += curr->right->data; } q.push(curr->right); } } return sum; } // driver program int main() { // construct binary tree Node* root = addNode(1); root->left = addNode(2); root->left->left = addNode(4); root->left->right = addNode(5); root->left->left->right = addNode(2); root->right = addNode(3); root->right->right = addNode(8); root->right->right->left = addNode(6); root->right->right->right = addNode(7); int sum = rightLeafSum(root); cout << sum << endl; return 0; }
np
linear
#include <bits/stdc++.h> using namespace std; //Building a tree node having left and right pointers set to null initially struct Node { Node* left; Node* right; int data; //constructor to set the data of the newly created tree node Node(int element){ data = element; this->left = nullptr; this->right = nullptr; } }; int longestPathLeaf(Node* root){ /* structure to store current Node,it's level and sum in the path*/ struct Element{ Node* data; int level; int sum; }; /* maxSumLevel stores maximum sum so far in the path maxLevel stores maximum level so far */ int maxSumLevel = root->data,maxLevel = 0; /* queue to implement level order traversal */ list<Element> que; Element e; /* Each element variable stores the current Node, it's level, sum in the path */ e.data = root; e.level = 0; e.sum = root->data; /* push the root element*/ que.push_back(e); /* do level order traversal on the tree*/ while(!que.empty()){ Element front = que.front(); Node* curr = front.data; que.pop_front(); /* if the level of current front element is greater than the maxLevel so far then update maxSum*/ if(front.level > maxLevel){ maxSumLevel = front.sum; maxLevel = front.level; } /* if another path competes then update if the sum is greater than the previous path of same height*/ else if(front.level == maxLevel && front.sum > maxSumLevel) maxSumLevel = front.sum; /* push the left element if exists*/ if(curr->left){ e.data = curr->left; e.sum = e.data->data; e.sum += front.sum; e.level = front.level+1; que.push_back(e); } /*push the right element if exists*/ if(curr->right){ e.data = curr->right; e.sum = e.data->data; e.sum += front.sum; e.level = front.level+1; que.push_back(e); } } /*return the answer*/ return maxSumLevel; } //Helper function int main() { Node* root = new Node(4); root->left = new Node(2); root->right = new Node(5); root->left->left = new Node(7); root->left->right = new Node(1); root->right->left = new Node(2); root->right->right = new Node(3); root->left->right->left = new Node(6); cout << longestPathLeaf(root) << "\n"; return 0; }
linear
linear
// C++ program to find maximum path //sum between two leaves of a binary tree #include <bits/stdc++.h> using namespace std; // A binary tree node struct Node { int data; struct Node* left, *right; }; // Utility function to allocate memory for a new node struct Node* newNode(int data) { struct Node* node = new(struct Node); node->data = data; node->left = node->right = NULL; return (node); } // Utility function to find maximum of two integers int max(int a, int b) { return (a >= b)? a: b; } // A utility function to find the maximum sum between any // two leaves.This function calculates two values: // 1) Maximum path sum between two leaves which is stored // in res. // 2) The maximum root to leaf path sum which is returned. // If one side of root is empty, then it returns INT_MIN int maxPathSumUtil(struct Node *root, int &res) { // Base cases if (root==NULL) return 0; if (!root->left && !root->right) return root->data; // Find maximum sum in left and right subtree. Also // find maximum root to leaf sums in left and right // subtrees and store them in ls and rs int ls = maxPathSumUtil(root->left, res); int rs = maxPathSumUtil(root->right, res); // If both left and right children exist if (root->left && root->right) { // Update result if needed res = max(res, ls + rs + root->data); // Return maximum possible value for root being // on one side return max(ls, rs) + root->data; } // If any of the two children is empty, return // root sum for root being on one side return (!root->left)? rs + root->data: ls + root->data; } // The main function which returns sum of the maximum // sum path between two leaves. This function mainly // uses maxPathSumUtil() int maxPathSum(struct Node *root) { int res = INT_MIN; int val = maxPathSumUtil(root, res); //--- for test case --- // 7 // / \ // Null -3 // (case - 1) // value of res will be INT_MIN but the answer is 4 , which is returned by the // function maxPathSumUtil(). if(root->left && root->right) return res; return max(res, val); } // Driver Code int main() { struct Node *root = newNode(-15); root->left = newNode(5); root->right = newNode(6); root->left->left = newNode(-8); root->left->right = newNode(1); root->left->left->left = newNode(2); root->left->left->right = newNode(6); root->right->left = newNode(3); root->right->right = newNode(9); root->right->right->right= newNode(0); root->right->right->right->left= newNode(4); root->right->right->right->right= newNode(-1); root->right->right->right->right->left= newNode(10); cout << "Max pathSum of the given binary tree is " << maxPathSum(root); return 0; }
linear
linear
// C++ program to print all paths with sum k. #include <bits/stdc++.h> using namespace std; // utility function to print contents of // a vector from index i to it's end void printVector(const vector<int>& v, int i) { for (int j = i; j < v.size(); j++) cout << v[j] << " "; cout << endl; } // binary tree node struct Node { int data; Node *left, *right; Node(int x) { data = x; left = right = NULL; } }; // This function prints all paths that have sum k void printKPathUtil(Node* root, vector<int>& path, int k) { // empty node if (!root) return; // add current node to the path path.push_back(root->data); // check if there's any k sum path // in the left sub-tree. printKPathUtil(root->left, path, k); // check if there's any k sum path // in the right sub-tree. printKPathUtil(root->right, path, k); // check if there's any k sum path that // terminates at this node // Traverse the entire path as // there can be negative elements too int f = 0; for (int j = path.size() - 1; j >= 0; j--) { f += path[j]; // If path sum is k, print the path if (f == k) printVector(path, j); } // Remove the current element from the path path.pop_back(); } // A wrapper over printKPathUtil() void printKPath(Node* root, int k) { vector<int> path; printKPathUtil(root, path, k); } // Driver code int main() { Node* root = new Node(1); root->left = new Node(3); root->left->left = new Node(2); root->left->right = new Node(1); root->left->right->left = new Node(1); root->right = new Node(-1); root->right->left = new Node(4); root->right->left->left = new Node(1); root->right->left->right = new Node(2); root->right->right = new Node(5); root->right->right->right = new Node(2); int k = 5; printKPath(root, k); return 0; }
logn
linear
// C++ program to find if there is a subtree with // given sum #include<bits/stdc++.h> using namespace std; /* A binary tree node has data, pointer to left child and a pointer to right child */ struct Node { int data; struct Node* left, *right; }; /* utility that allocates a new node with the given data and NULL left and right pointers. */ struct Node* newnode(int data) { struct Node* node = new Node; node->data = data; node->left = node->right = NULL; return (node); } // function to check if there exist any subtree with given sum // cur_sum --> sum of current subtree from ptr as root // sum_left --> sum of left subtree from ptr as root // sum_right --> sum of right subtree from ptr as root bool sumSubtreeUtil(struct Node *ptr, int *cur_sum, int sum) { // base condition if (ptr == NULL) { *cur_sum = 0; return false; } // Here first we go to left sub-tree, then right subtree // then first we calculate sum of all nodes of subtree // having ptr as root and assign it as cur_sum // cur_sum = sum_left + sum_right + ptr->data // after that we check if cur_sum == sum int sum_left = 0, sum_right = 0; return ( sumSubtreeUtil(ptr->left, ∑_left, sum) || sumSubtreeUtil(ptr->right, ∑_right, sum) || ((*cur_sum = sum_left + sum_right + ptr->data) == sum)); } // Wrapper over sumSubtreeUtil() bool sumSubtree(struct Node *root, int sum) { // Initialize sum of subtree with root int cur_sum = 0; return sumSubtreeUtil(root, &cur_sum, sum); } // driver program to run the case int main() { struct Node *root = newnode(8); root->left = newnode(5); root->right = newnode(4); root->left->left = newnode(9); root->left->right = newnode(7); root->left->right->left = newnode(1); root->left->right->right = newnode(12); root->left->right->right->right = newnode(2); root->right->right = newnode(11); root->right->right->left = newnode(3); int sum = 22; if (sumSubtree(root, sum)) cout << "Yes"; else cout << "No"; return 0; }
logn
linear
// C++ implementation to count subtrees that // sum up to a given value x #include <bits/stdc++.h> using namespace std; // structure of a node of binary tree struct Node { int data; Node *left, *right; }; // function to get a new node Node* getNode(int data) { // allocate space Node* newNode = (Node*)malloc(sizeof(Node)); // put in the data newNode->data = data; newNode->left = newNode->right = NULL; return newNode; } // function to count subtrees that // sum up to a given value x int countSubtreesWithSumX(Node* root, int& count, int x) { // if tree is empty if (!root) return 0; // sum of nodes in the left subtree int ls = countSubtreesWithSumX(root->left, count, x); // sum of nodes in the right subtree int rs = countSubtreesWithSumX(root->right, count, x); // sum of nodes in the subtree rooted // with 'root->data' int sum = ls + rs + root->data; // if true if (sum == x) count++; // return subtree's nodes sum return sum; } // utility function to count subtrees that // sum up to a given value x int countSubtreesWithSumXUtil(Node* root, int x) { // if tree is empty if (!root) return 0; int count = 0; // sum of nodes in the left subtree int ls = countSubtreesWithSumX(root->left, count, x); // sum of nodes in the right subtree int rs = countSubtreesWithSumX(root->right, count, x); // if tree's nodes sum == x if ((ls + rs + root->data) == x) count++; // required count of subtrees return count; } // Driver program to test above int main() { /* binary tree creation 5 / \ -10 3 / \ / \ 9 8 -4 7 */ Node* root = getNode(5); root->left = getNode(-10); root->right = getNode(3); root->left->left = getNode(9); root->left->right = getNode(8); root->right->left = getNode(-4); root->right->right = getNode(7); int x = 7; cout << "Count = " << countSubtreesWithSumXUtil(root, x); return 0; }
logn
linear
// C++ program to find if // there is a subtree with // given sum #include <bits/stdc++.h> using namespace std; // Structure of a node of binary tree struct Node { int data; Node *left, *right; }; // Function to get a new node Node* getNode(int data) { // Allocate space Node* newNode = (Node*)malloc(sizeof(Node)); // Put in the data newNode->data = data; newNode->left = newNode->right = NULL; return newNode; } // Utility function to count subtrees that // sum up to a given value x int countSubtreesWithSumXUtil(Node* root, int x) { static int count = 0; static Node* ptr = root; int l = 0, r = 0; if (root == NULL) return 0; l += countSubtreesWithSumXUtil(root->left, x); r += countSubtreesWithSumXUtil(root->right, x); if (l + r + root->data == x) count++; if (ptr != root) return l + root->data + r; return count; } // Driver code int main() { /* binary tree creation 5 / \ -10 3 / \ / \ 9 8 -4 7 */ Node* root = getNode(5); root->left = getNode(-10); root->right = getNode(3); root->left->left = getNode(9); root->left->right = getNode(8); root->right->left = getNode(-4); root->right->right = getNode(7); int x = 7; cout << "Count = " << countSubtreesWithSumXUtil(root, x); return 0; } // This code is contributed by Sadik Ali
logn
linear
// C++ implementation to find maximum spiral sum #include <bits/stdc++.h> using namespace std; // structure of a node of binary tree struct Node { int data; Node *left, *right; }; // A utility function to create a new node Node* newNode(int data) { // allocate space Node* node = new Node; // put in the data node->data = data; node->left = node->right = NULL; return node; } // function to find the maximum sum contiguous subarray. // implements kadane's algorithm int maxSum(vector<int> arr, int n) { // to store the maximum value that is ending // up to the current index int max_ending_here = INT_MIN; // to store the maximum value encountered so far int max_so_far = INT_MIN; // traverse the array elements for (int i = 0; i < n; i++) { // if max_ending_here < 0, then it could // not possibly contribute to the maximum // sum further if (max_ending_here < 0) max_ending_here = arr[i]; // else add the value arr[i] to max_ending_here else max_ending_here += arr[i]; // update max_so_far max_so_far = max(max_so_far, max_ending_here); } // required maximum sum contiguous subarray value return max_so_far; } // function to find maximum spiral sum int maxSpiralSum(Node* root) { // if tree is empty if (root == NULL) return 0; // Create two stacks to store alternate levels stack<Node*> s1; // For levels from right to left stack<Node*> s2; // For levels from left to right // vector to store spiral order traversal // of the binary tree vector<int> arr; // Push first level to first stack 's1' s1.push(root); // traversing tree in spiral form until // there are elements in any one of the // stacks while (!s1.empty() || !s2.empty()) { // traverse current level from s1 and // push nodes of next level to s2 while (!s1.empty()) { Node* temp = s1.top(); s1.pop(); // push temp-data to 'arr' arr.push_back(temp->data); // Note that right is pushed before left if (temp->right) s2.push(temp->right); if (temp->left) s2.push(temp->left); } // traverse current level from s2 and // push nodes of next level to s1 while (!s2.empty()) { Node* temp = s2.top(); s2.pop(); // push temp-data to 'arr' arr.push_back(temp->data); // Note that left is pushed before right if (temp->left) s1.push(temp->left); if (temp->right) s1.push(temp->right); } } // required maximum spiral sum return maxSum(arr, arr.size()); } // Driver program to test above int main() { Node* root = newNode(-2); root->left = newNode(-3); root->right = newNode(4); root->left->left = newNode(5); root->left->right = newNode(1); root->right->left = newNode(-2); root->right->right = newNode(-1); root->left->left->left = newNode(-3); root->right->right->right = newNode(2); cout << "Maximum Spiral Sum = " << maxSpiralSum(root); return 0; }
linear
linear
// C++ implementation to find the sum of // leaf nodes at minimum level #include <bits/stdc++.h> using namespace std; // structure of a node of binary tree struct Node { int data; Node *left, *right; }; // function to get a new node Node* getNode(int data) { // allocate space Node* newNode = (Node*)malloc(sizeof(Node)); // put in the data newNode->data = data; newNode->left = newNode->right = NULL; return newNode; } // function to find the sum of // leaf nodes at minimum level int sumOfLeafNodesAtMinLevel(Node* root) { // if tree is empty if (!root) return 0; // if there is only one node if (!root->left && !root->right) return root->data; // queue used for level order traversal queue<Node*> q; int sum = 0; bool f = 0; // push root node in the queue 'q' q.push(root); while (f == 0) { // count number of nodes in the // current level int nc = q.size(); // traverse the current level nodes while (nc--) { // get front element from 'q' Node* top = q.front(); q.pop(); // if it is a leaf node if (!top->left && !top->right) { // accumulate data to 'sum' sum += top->data; // set flag 'f' to 1, to signify // minimum level for leaf nodes // has been encountered f = 1; } else { // if top's left and right child // exists, then push them to 'q' if (top->left) q.push(top->left); if (top->right) q.push(top->right); } } } // required sum return sum; } // Driver program to test above int main() { // binary tree creation Node* root = getNode(1); root->left = getNode(2); root->right = getNode(3); root->left->left = getNode(4); root->left->right = getNode(5); root->right->left = getNode(6); root->right->right = getNode(7); root->left->right->left = getNode(8); root->right->left->right = getNode(9); cout << "Sum = " << sumOfLeafNodesAtMinLevel(root); return 0; }
linear
linear
#include <bits/stdc++.h> using namespace std; struct Node { int data; Node *left, *right; }; // function to get a new node Node* getNode(int data) { // allocate space Node* newNode = (Node*)malloc(sizeof(Node)); // put in the data newNode->data = data; newNode->left = newNode->right = NULL; return newNode; } map <int, vector <int>> mp; void solve(Node* root, int level) { if(root == NULL) return; if(root->left == NULL && root->right == NULL) mp[level].push_back(root->data); solve(root->left, level+1); solve(root->right, level+1); } int minLeafSum(Node *root) { solve(root, 0); int sum = 0; for(auto i:mp) { for(auto j:i.second) { sum += j; } return sum; } } int main() { // binary tree creation Node* root = getNode(1); root->left = getNode(2); root->right = getNode(3); root->left->left = getNode(4); root->left->right = getNode(5); root->right->left = getNode(6); root->right->right = getNode(7); cout << "Sum = "<< minLeafSum(root); return 0; }
linear
linear
#include <bits/stdc++.h> using namespace std; #define bool int /* A binary tree node has data, pointer to left child and a pointer to right child */ class node { public: int data; node* left; node* right; }; /* Given a tree and a sum, return true if there is a path from the root down to a leaf, such that adding up all the values along the path equals the given sum. Strategy: subtract the node value from the sum when recurring down, and check to see if the sum is 0 when you when you reach the leaf node. */ bool hasPathSum(node* Node, int sum) { if (Node == NULL) return 0; bool ans = 0; int subSum = sum - Node->data; /* If we reach a leaf node and sum becomes 0 then return * true*/ if (subSum == 0 && Node->left == NULL && Node->right == NULL) return 1; /* otherwise check both subtrees */ if (Node->left) ans = ans || hasPathSum(Node->left, subSum); if (Node->right) ans = ans || hasPathSum(Node->right, subSum); return ans; } /* UTILITY FUNCTIONS */ /* Helper function that allocates a new node with the given data and NULL left and right pointers. */ node* newnode(int data) { node* Node = new node(); Node->data = data; Node->left = NULL; Node->right = NULL; return (Node); } // Driver's Code int main() { int sum = 21; /* Constructed binary tree is 10 / \ 8 2 / \ / 3 5 2 */ node* root = newnode(10); root->left = newnode(8); root->right = newnode(2); root->left->left = newnode(3); root->left->right = newnode(5); root->right->left = newnode(2); // Function call if (hasPathSum(root, sum)) cout << "There is a root-to-leaf path with sum " << sum; else cout << "There is no root-to-leaf path with sum " << sum; return 0; } // This code is contributed by rathbhupendra
logn
linear
// C++ program to find sum of all paths from root to leaves // A Binary tree node #include <bits/stdc++.h> using namespace std; // A Binary tree node class Node { public: int data; Node *left, *right; // Constructor to create a new node Node(int val) { data = val; left = right = NULL; } }; void treePathsSumUtil(Node* root, vector<string> currPath, vector<vector<string>> &allPath) { // Base Case if (root == NULL) return; // append the root data in string format in currPath currPath.push_back((to_string)(root->data)); // if we found a leaf node we copy the currPath to allPath if (root->left == NULL && root->right == NULL) allPath.push_back(currPath); // traverse in the left subtree treePathsSumUtil(root->left, currPath, allPath); // traverse in the right subtree treePathsSumUtil(root->right, currPath, allPath); // remove the current element from the path currPath.pop_back(); } int treePathsSum(Node* root) { // store all the root to leaf path in allPath vector<vector<string>> allPath; vector<string> v; treePathsSumUtil(root, v, allPath); // store the sum int s = 0; for(auto pathNumber : allPath) { string k=""; // join the pathNumbers to convert them // into the number to calculate sum for(auto x: pathNumber) k = k+x; s += stoi(k); } return s; } // Driver code int main() { Node *root = new Node(6); root->left = new Node(3); root->right = new Node(5); root->left->left = new Node(2); root->left->right = new Node(5); root->right->right = new Node(4); root->left->right->left = new Node(7); root->left->right->right = new Node(4); cout<<"Sum of all paths is "<<treePathsSum(root); return 0; } // This code is contributed by Abhijeet Kumar(abhijeet19403)
linear
quadratic
// Find root of tree where children // sum for every node id is given. #include<bits/stdc++.h> using namespace std; int findRoot(pair<int, int> arr[], int n) { // Every node appears once as an id, and // every node except for the root appears // once in a sum. So if we subtract all // the sums from all the ids, we're left // with the root id. int root = 0; for (int i=0; i<n; i++) root += (arr[i].first - arr[i].second); return root; } // Driver code int main() { pair<int, int> arr[] = {{1, 5}, {2, 0}, {3, 0}, {4, 0}, {5, 5}, {6, 5}}; int n = sizeof(arr)/sizeof(arr[0]); printf("%d\n", findRoot(arr, n)); return 0; }
constant
linear
// C++ implementation to replace each node // in binary tree with the sum of its inorder // predecessor and successor #include <bits/stdc++.h> using namespace std; // node of a binary tree struct Node { int data; struct Node* left, *right; }; // function to get a new node of a binary tree struct Node* getNode(int data) { // allocate node struct Node* new_node = (struct Node*)malloc(sizeof(struct Node)); // put in the data; new_node->data = data; new_node->left = new_node->right = NULL; return new_node; } // function to store the inorder traversal // of the binary tree in 'arr' void storeInorderTraversal(struct Node* root, vector<int>& arr) { // if root is NULL if (!root) return; // first recur on left child storeInorderTraversal(root->left, arr); // then store the root's data in 'arr' arr.push_back(root->data); // now recur on right child storeInorderTraversal(root->right, arr); } // function to replace each node with the sum of its // inorder predecessor and successor void replaceNodeWithSum(struct Node* root, vector<int> arr, int* i) { // if root is NULL if (!root) return; // first recur on left child replaceNodeWithSum(root->left, arr, i); // replace node's data with the sum of its // inorder predecessor and successor root->data = arr[*i - 1] + arr[*i + 1]; // move 'i' to point to the next 'arr' element ++*i; // now recur on right child replaceNodeWithSum(root->right, arr, i); } // Utility function to replace each node in binary // tree with the sum of its inorder predecessor // and successor void replaceNodeWithSumUtil(struct Node* root) { // if tree is empty if (!root) return; vector<int> arr; // store the value of inorder predecessor // for the leftmost leaf arr.push_back(0); // store the inorder traversal of the tree in 'arr' storeInorderTraversal(root, arr); // store the value of inorder successor // for the rightmost leaf arr.push_back(0); // replace each node with the required sum int i = 1; replaceNodeWithSum(root, arr, &i); } // function to print the preorder traversal // of a binary tree void preorderTraversal(struct Node* root) { // if root is NULL if (!root) return; // first print the data of node cout << root->data << " "; // then recur on left subtree preorderTraversal(root->left); // now recur on right subtree preorderTraversal(root->right); } // Driver program to test above int main() { // binary tree formation struct Node* root = getNode(1); /* 1 */ root->left = getNode(2); /* / \ */ root->right = getNode(3); /* 2 3 */ root->left->left = getNode(4); /* / \ / \ */ root->left->right = getNode(5); /* 4 5 6 7 */ root->right->left = getNode(6); root->right->right = getNode(7); cout << "Preorder Traversal before tree modification:n"; preorderTraversal(root); replaceNodeWithSumUtil(root); cout << "\nPreorder Traversal after tree modification:n"; preorderTraversal(root); return 0; }
linear
linear
// C++ implementation to replace each node // in binary tree with the sum of its inorder // predecessor and successor #include <bits/stdc++.h> using namespace std; // node of a binary tree struct Node { int data; struct Node* left, *right; }; // function to get a new node of a binary tree struct Node* getNode(int data) { // allocate node struct Node* new_node = (struct Node*)malloc(sizeof(struct Node)); // put in the data; new_node->data = data; new_node->left = new_node->right = NULL; return new_node; } // function to print the preorder traversal // of a binary tree void preorderTraversal(struct Node* root) { // if root is NULL if (!root) return; // first print the data of node cout << root->data << " "; // then recur on left subtree preorderTraversal(root->left); // now recur on right subtree preorderTraversal(root->right); } void inOrderTraverse(struct Node* root, struct Node* &prev, int &prevVal) { if(root == NULL) return; inOrderTraverse(root->left, prev, prevVal); if(prev == NULL) { prev = root; prevVal = 0; } else { int temp = prev->data; prev->data = prevVal + root->data; prev = root; prevVal = temp; } inOrderTraverse(root->right, prev, prevVal); } // Driver program to test above int main() { // binary tree formation struct Node* root = getNode(1); /* 1 */ root->left = getNode(2); /* / \ */ root->right = getNode(3); /* 2 3 */ root->left->left = getNode(4); /* / \ / \ */ root->left->right = getNode(5); /* 4 5 6 7 */ root->right->left = getNode(6); root->right->right = getNode(7); cout << "Preorder Traversal before tree modification:\n"; preorderTraversal(root); struct Node* prev = NULL; int prevVal = -1; inOrderTraverse(root, prev, prevVal); // update righmost node. prev->data = prevVal; cout << "\nPreorder Traversal after tree modification:\n"; preorderTraversal(root); return 0; }
linear
linear
// C++ Program for Lowest Common Ancestor // in a Binary Tree // A O(n) solution to find LCA // of two given values n1 and n2 #include <bits/stdc++.h> using namespace std; // A Binary Tree node struct Node { int key; struct Node *left, *right; }; // Utility function creates a new binary tree node with // given key Node* newNode(int k) { Node* temp = new Node; temp->key = k; temp->left = temp->right = NULL; return temp; } // Finds the path from root node to given root of the tree, // Stores the path in a vector path[], returns true if path // exists otherwise false bool findPath(Node* root, vector<int>& path, int k) { // base case if (root == NULL) return false; // Store this node in path vector. The node will be // removed if not in path from root to k path.push_back(root->key); // See if the k is same as root's key if (root->key == k) return true; // Check if k is found in left or right sub-tree if ((root->left && findPath(root->left, path, k)) || (root->right && findPath(root->right, path, k))) return true; // If not present in subtree rooted with root, remove // root from path[] and return false path.pop_back(); return false; } // Returns LCA if node n1, n2 are present in the given // binary tree, otherwise return -1 int findLCA(Node* root, int n1, int n2) { // to store paths to n1 and n2 from the root vector<int> path1, path2; // Find paths from root to n1 and root to n2. If either // n1 or n2 is not present, return -1 if (!findPath(root, path1, n1) || !findPath(root, path2, n2)) return -1; /* Compare the paths to get the first different value */ int i; for (i = 0; i < path1.size() && i < path2.size(); i++) if (path1[i] != path2[i]) break; return path1[i - 1]; } // Driver program to test above functions int main() { // Let us create the Binary Tree shown in above diagram. Node* root = newNode(1); root->left = newNode(2); root->right = newNode(3); root->left->left = newNode(4); root->left->right = newNode(5); root->right->left = newNode(6); root->right->right = newNode(7); cout << "LCA(4, 5) = " << findLCA(root, 4, 5); cout << "\nLCA(4, 6) = " << findLCA(root, 4, 6); cout << "\nLCA(3, 4) = " << findLCA(root, 3, 4); cout << "\nLCA(2, 4) = " << findLCA(root, 2, 4); return 0; }
linear
linear
/* C++ Program to find LCA of n1 and n2 using one traversal * of Binary Tree */ #include <bits/stdc++.h> using namespace std; // A Binary Tree Node struct Node { struct Node *left, *right; int key; }; // Utility function to create a new tree Node Node* newNode(int key) { Node* temp = new Node; temp->key = key; temp->left = temp->right = NULL; return temp; } // This function returns pointer to LCA of two given values // n1 and n2. This function assumes that n1 and n2 are // present in Binary Tree struct Node* findLCA(struct Node* root, int n1, int n2) { // Base case if (root == NULL) return NULL; // If either n1 or n2 matches with root's key, report // the presence by returning root (Note that if a key is // ancestor of other, then the ancestor key becomes LCA if (root->key == n1 || root->key == n2) return root; // Look for keys in left and right subtrees Node* left_lca = findLCA(root->left, n1, n2); Node* right_lca = findLCA(root->right, n1, n2); // If both of the above calls return Non-NULL, then one // key is present in once subtree and other is present // in other, So this node is the LCA if (left_lca && right_lca) return root; // Otherwise check if left subtree or right subtree is // LCA return (left_lca != NULL) ? left_lca : right_lca; } // Driver program to test above functions int main() { // Let us create binary tree given in the above example Node* root = newNode(1); root->left = newNode(2); root->right = newNode(3); root->left->left = newNode(4); root->left->right = newNode(5); root->right->left = newNode(6); root->right->right = newNode(7); cout << "LCA(4, 5) = " << findLCA(root, 4, 5)->key; cout << "\nLCA(4, 6) = " << findLCA(root, 4, 6)->key; cout << "\nLCA(3, 4) = " << findLCA(root, 3, 4)->key; cout << "\nLCA(2, 4) = " << findLCA(root, 2, 4)->key; return 0; } // This code is contributed by Aditya Kumar (adityakumar129)
logn
linear
/* C++ program to find LCA of n1 and n2 using one traversal of Binary Tree. It handles all cases even when n1 or n2 is not there in Binary Tree */ #include <iostream> using namespace std; // A Binary Tree Node struct Node { struct Node *left, *right; int key; }; // Utility function to create a new tree Node Node* newNode(int key) { Node* temp = new Node; temp->key = key; temp->left = temp->right = NULL; return temp; } // This function returns pointer to LCA of two given // valuesn1 and n2. struct Node* findLCAUtil(struct Node* root, int n1, int n2) { // Base case if (root == NULL) return NULL; // If either n1 or n2 matches with root's key, report // the presence by returning root if (root->key == n1 || root->key == n2) return root; // Look for keys in left and right subtrees Node* left_lca = findLCAUtil(root->left, n1, n2); Node* right_lca = findLCAUtil(root->right, n1, n2); // If both of the above calls return Non-NULL nodes, // then one key is present in once subtree and other is // present in other, So this node is the LCA if (left_lca and right_lca) return root; // Otherwise check if left subtree or right subtree is // LCA return (left_lca != NULL) ? left_lca : right_lca; } // Returns true if key k is present in tree rooted with root bool find(Node* root, int k) { // Base Case if (root == NULL) return false; // If key is present at root, or in left subtree or // right subtree, return true; if (root->key == k || find(root->left, k) || find(root->right, k)) return true; // Else return false return false; } // This function returns LCA of n1 and n2 only if both n1 // and n2 are present in tree, otherwise returns NULL; Node* findLCA(Node* root, int n1, int n2) { // Return LCA only if both n1 and n2 are present in tree if (find(root, n1) and find(root, n2)) return findLCAUtil(root, n1, n2); // Else return NULL return NULL; } // Driver program to test above functions int main() { // Let us create a binary tree given in the above // example Node* root = newNode(1); root->left = newNode(2); root->right = newNode(3); root->left->left = newNode(4); root->left->right = newNode(5); root->right->left = newNode(6); root->right->right = newNode(7); Node* lca = findLCA(root, 4, 5); if (lca != NULL) cout << "LCA(4, 5) = " << lca->key; else cout << "Keys are not present "; lca = findLCA(root, 4, 10); if (lca != NULL) cout << "\nLCA(4, 10) = " << lca->key; else cout << "\nKeys are not present "; return 0; } // This code is contributed by Kshitij Dwivedi // (kshitijdwivedi28)
logn
linear
// C++ program to find maximum difference between node // and its ancestor #include <bits/stdc++.h> using namespace std; /* A binary tree node has key, pointer to left child and a pointer to right child */ struct Node { int key; struct Node *left, *right; }; /* To create a newNode of tree and return pointer */ struct Node* newNode(int key) { Node* temp = new Node; temp->key = key; temp->left = temp->right = NULL; return (temp); } /* Recursive function to calculate maximum ancestor-node difference in binary tree. It updates value at 'res' to store the result. The returned value of this function is minimum value in subtree rooted with 't' */ int maxDiffUtil(Node* t, int* res) { /* Returning Maximum int value if node is not there (one child case) */ if (t == NULL) return INT_MAX; /* If leaf node then just return node's value */ if (t->left == NULL && t->right == NULL) return t->key; /* Recursively calling left and right subtree for minimum value */ int val = min(maxDiffUtil(t->left, res), maxDiffUtil(t->right, res)); /* Updating res if (node value - minimum value from subtree) is bigger than res */ *res = max(*res, t->key - val); /* Returning minimum value got so far */ return min(val, t->key); } /* This function mainly calls maxDiffUtil() */ int maxDiff(Node* root) { // Initialising result with minimum int value int res = INT_MIN; maxDiffUtil(root, &res); return res; } /* Helper function to print inorder traversal of binary tree */ void inorder(Node* root) { if (root) { inorder(root->left); cout << root->key << " "; inorder(root->right); } } // Driver program to test above functions int main() { // Making above given diagram's binary tree Node* root; root = newNode(8); root->left = newNode(3); root->left->left = newNode(1); root->left->right = newNode(6); root->left->right->left = newNode(4); root->left->right->right = newNode(7); root->right = newNode(10); root->right->right = newNode(14); root->right->right->left = newNode(13); cout << maxDiff(root); }
linear
linear
// C++ program to count number of ways to color // a N node skewed tree with k colors such that // parent and children have different colors. #include <bits/stdc++.h> using namespace std; // fast_way is recursive // method to calculate power int fastPow(int N, int K) { if (K == 0) return 1; int temp = fastPow(N, K / 2); if (K % 2 == 0) return temp * temp; else return N * temp * temp; } int countWays(int N, int K) { return K * fastPow(K - 1, N - 1); } // driver program int main() { int N = 3, K = 3; cout << countWays(N, K); return 0; }
constant
logn
// C++ program to print size of tree in iterative #include<iostream> #include<queue> using namespace std; struct Node { int data; Node *left, *right; }; // A utility function to // create a new Binary Tree Node Node *newNode(int data) { Node *temp = new Node; temp->data = data; temp->left = NULL; temp->right = NULL; return temp; } // return size of tree int sizeoftree(Node *root) { // if tree is empty it will // return 0 if(root == NULL) return 0; // Using level order Traversal. queue<Node *> q; int count = 1; q.push(root); while(!q.empty()) { Node *temp = q.front(); if(temp->left) { // Enqueue left child q.push(temp->left); // Increment count count++; } if(temp->right) { // Enqueue right child q.push(temp->right); // Increment count count++; } q.pop(); } return count; } // Driver Code int main() { Node *root = newNode(1); root->left = newNode(2); root->right = newNode(3); root->left->left = newNode(4); root->left->right = newNode(5); cout << "Size of the tree is " << sizeoftree(root) << endl; return 0; } // This code is contributed by SHAKEELMOHAMMAD
np
linear
// C++ program to find height of tree #include <bits/stdc++.h> using namespace std; /* A binary tree node has data, pointer to left child and a pointer to right child */ class node { public: int data; node* left; node* right; }; /* Compute the "maxDepth" of a tree -- the number of nodes along the longest path from the root node down to the farthest leaf node.*/ int maxDepth(node* node) { if (node == NULL) return 0; else { /* compute the depth of each subtree */ int lDepth = maxDepth(node->left); int rDepth = maxDepth(node->right); /* use the larger one */ if (lDepth > rDepth) return (lDepth + 1); else return (rDepth + 1); } } /* Helper function that allocates a new node with the given data and NULL left and right pointers. */ node* newNode(int data) { node* Node = new node(); Node->data = data; Node->left = NULL; Node->right = NULL; return (Node); } // Driver code int main() { node* root = newNode(1); root->left = newNode(2); root->right = newNode(3); root->left->left = newNode(4); root->left->right = newNode(5); cout << "Height of tree is " << maxDepth(root); return 0; } // This code is contributed by Amit Srivastav
linear
linear
#include <bits/stdc++.h> #include <iostream> using namespace std; // A Tree node struct Node { int key; struct Node *left, *right; }; // Utility function to create a new node Node* newNode(int key) { Node* temp = new Node; temp->key = key; temp->left = temp->right = NULL; return (temp); } /*Function to find the height(depth) of the tree*/ int height(struct Node* root) { // Initialising a variable to count the // height of tree int depth = 0; queue<Node*> q; // Pushing first level element along with NULL q.push(root); q.push(NULL); while (!q.empty()) { Node* temp = q.front(); q.pop(); // When NULL encountered, increment the value if (temp == NULL) { depth++; } // If NULL not encountered, keep moving if (temp != NULL) { if (temp->left) { q.push(temp->left); } if (temp->right) { q.push(temp->right); } } // If queue still have elements left, // push NULL again to the queue. else if (!q.empty()) { q.push(NULL); } } return depth; } // Driver program int main() { // Let us create Binary Tree shown in above example Node* root = newNode(1); root->left = newNode(2); root->right = newNode(3); root->left->left = newNode(4); root->left->right = newNode(5); cout << "Height(Depth) of tree is: " << height(root); }
linear
linear
// C++ program for above approach #include <bits/stdc++.h> using namespace std; // A Tree node struct Node { int key; struct Node *left, *right; }; // Utility function to create a new node Node* newNode(int key) { Node* temp = new Node; temp->key = key; temp->left = temp->right = NULL; return (temp); } /*Function to find the height(depth) of the tree*/ int height(Node* root) { // Initialising a variable to count the // height of tree queue<Node*> q; q.push(root); int height = 0; while (!q.empty()) { int size = q.size(); for (int i = 0; i < size; i++) { Node* temp = q.front(); q.pop(); if (temp->left != NULL) { q.push(temp->left); } if (temp->right != NULL) { q.push(temp->right); } } height++; } return height; } // Driver program int main() { // Let us create Binary Tree shown in above example Node* root = newNode(1); root->left = newNode(2); root->right = newNode(3); root->left->left = newNode(4); root->left->right = newNode(5); cout << "Height(Depth) of tree is: " << height(root); } // This code is contributed by Abhijeet Kumar(abhijeet19403)
linear
linear
#include <iostream> #include <queue> using namespace std; // This approach counts the number of nodes from root to the // leaf to calculate the height of the tree. // Defining the structure of a Node. class Node { public: int data; Node* left; Node* right; }; // Helper function to create a newnode. // Input: Data for the newnode. // Return: Address of the newly created node. Node* createNode(int data) { Node* newnode = new Node(); newnode->data = data; newnode->left = NULL; newnode->right = NULL; return newnode; } // Function to calculate the height of given Binary Tree. // Input: Address of the root node of Binary Tree. // Return: Height of Binary Tree as a integer. This includes // the number of nodes from root to the leaf. int calculateHeight(Node* root) { queue<Node*> nodesInLevel; int height = 0; int nodeCount = 0; // Calculate number of nodes in a level. Node* currentNode; // Pointer to store the address of a // node in the current level. if (root == NULL) { return 0; } nodesInLevel.push(root); while (!nodesInLevel.empty()) { // This while loop runs for every level and // increases the height by 1 in each iteration. If // the queue is empty then it implies that the last // level of tree has been parsed. height++; // Create another while loop which will insert all // the child nodes of the current level in the // queue. nodeCount = nodesInLevel.size(); while (nodeCount--) { currentNode = nodesInLevel.front(); // Check if the current nodes has left child and // insert it in the queue. if (currentNode->left != NULL) { nodesInLevel.push(currentNode->left); } // Check if the current nodes has right child // and insert it in the queue. if (currentNode->right != NULL) { nodesInLevel.push(currentNode->right); } // Once the children of the current node are // inserted. Delete the current node. nodesInLevel.pop(); } } return height; } // Driver Function. int main() { // Creating a binary tree. Node* root = NULL; root = createNode(1); root->left = createNode(2); root->left->left = createNode(4); root->left->right = createNode(5); root->right = createNode(3); cout << "The height of the binary tree using iterative " "method is: " << calculateHeight(root) << "."; return 0; }
linear
linear
// CPP program to find height of complete // binary tree from total nodes. #include <bits/stdc++.h> using namespace std; int height(int N) { return floor(log2(N)); } // driver node int main() { int N = 2; cout << height(N); return 0; }
constant
constant
/* Program to find height of the tree considering only even level leaves. */ #include <bits/stdc++.h> using namespace std; /* A binary tree node has data, pointer to left child and a pointer to right child */ struct Node { int data; struct Node* left; struct Node* right; }; int heightOfTreeUtil(Node* root, bool isEven) { // Base Case if (!root) return 0; if (!root->left && !root->right) { if (isEven) return 1; else return 0; } /*left stores the result of left subtree, and right stores the result of right subtree*/ int left = heightOfTreeUtil(root->left, !isEven); int right = heightOfTreeUtil(root->right, !isEven); /*If both left and right returns 0, it means there is no valid path till leaf node*/ if (left == 0 && right == 0) return 0; return (1 + max(left, right)); } /* Helper function that allocates a new node with the given data and NULL left and right pointers. */ struct Node* newNode(int data) { struct Node* node = (struct Node*)malloc(sizeof(struct Node)); node->data = data; node->left = NULL; node->right = NULL; return (node); } int heightOfTree(Node* root) { return heightOfTreeUtil(root, false); } /* Driver program to test above functions*/ int main() { // Let us create binary tree shown in above diagram struct Node* root = newNode(1); root->left = newNode(2); root->right = newNode(3); root->left->left = newNode(4); root->left->right = newNode(5); root->left->right->left = newNode(6); cout << "Height of tree is " << heightOfTree(root); return 0; }
linear
linear
/* CPP program to check if a tree is height-balanced or not */ #include <bits/stdc++.h> using namespace std; /* A binary tree node has data, pointer to left child and a pointer to right child */ class Node { public: int data; Node* left; Node* right; Node(int d) { int data = d; left = right = NULL; } }; // Function to calculate the height of a tree int height(Node* node) { // base case tree is empty if (node == NULL) return 0; // If tree is not empty then // height = 1 + max of left height // and right heights return 1 + max(height(node->left), height(node->right)); } // Returns true if binary tree // with root as root is height-balanced bool isBalanced(Node* root) { // for height of left subtree int lh; // for height of right subtree int rh; // If tree is empty then return true if (root == NULL) return 1; // Get the height of left and right sub trees lh = height(root->left); rh = height(root->right); if (abs(lh - rh) <= 1 && isBalanced(root->left) && isBalanced(root->right)) return 1; // If we reach here then tree is not height-balanced return 0; } // Driver code int main() { Node* root = new Node(1); root->left = new Node(2); root->right = new Node(3); root->left->left = new Node(4); root->left->right = new Node(5); root->left->left->left = new Node(8); if (isBalanced(root)) cout << "Tree is balanced"; else cout << "Tree is not balanced"; return 0; } // This code is contributed by rathbhupendra
linear
quadratic
// Recursive optimized C program to find the diameter of a // Binary Tree #include <bits/stdc++.h> using namespace std; // A binary tree node has data, pointer to left child // and a pointer to right child struct node { int data; struct node *left, *right; }; // function to create a new node of tree and returns pointer struct node* newNode(int data); // returns max of two integers int max(int a, int b) { return (a > b) ? a : b; } // function to Compute height of a tree. int height(struct node* node); // Function to get diameter of a binary tree int diameter(struct node* tree) { // base case where tree is empty if (tree == NULL) return 0; // get the height of left and right sub-trees int lheight = height(tree->left); int rheight = height(tree->right); // get the diameter of left and right sub-trees int ldiameter = diameter(tree->left); int rdiameter = diameter(tree->right); // Return max of following three // 1) Diameter of left subtree // 2) Diameter of right subtree // 3) Height of left subtree + height of right subtree + // 1 return max(lheight + rheight + 1, max(ldiameter, rdiameter)); } // UTILITY FUNCTIONS TO TEST diameter() FUNCTION // The function Compute the "height" of a tree. Height is // the number f nodes along the longest path from the root // node down to the farthest leaf node. int height(struct node* node) { // base case tree is empty if (node == NULL) return 0; // If tree is not empty then height = 1 + max of left // height and right heights return 1 + max(height(node->left), height(node->right)); } // Helper function that allocates a new node with the // given data and NULL left and right pointers. struct node* newNode(int data) { struct node* node = (struct node*)malloc(sizeof(struct node)); node->data = data; node->left = NULL; node->right = NULL; return (node); } // Driver Code int main() { /* Constructed binary tree is 1 / \ 2 3 / \ 4 5 */ struct node* root = newNode(1); root->left = newNode(2); root->right = newNode(3); root->left->left = newNode(4); root->left->right = newNode(5); // Function Call cout << "Diameter of the given binary tree is " << diameter(root); return 0; } // This code is contributed by shivanisinghss2110
linear
quadratic
// Recursive optimized C++ program to find the diameter of a // Binary Tree #include <bits/stdc++.h> using namespace std; // A binary tree node has data, pointer to left child // and a pointer to right child struct node { int data; struct node *left, *right; }; // function to create a new node of tree and returns pointer struct node* newNode(int data); int diameterOpt(struct node* root, int* height) { // lh --> Height of left subtree // rh --> Height of right subtree int lh = 0, rh = 0; // ldiameter --> diameter of left subtree // rdiameter --> Diameter of right subtree int ldiameter = 0, rdiameter = 0; if (root == NULL) { *height = 0; return 0; // diameter is also 0 } // Get the heights of left and right subtrees in lh and // rh And store the returned values in ldiameter and // ldiameter ldiameter = diameterOpt(root->left, &lh); rdiameter = diameterOpt(root->right, &rh); // Height of current node is max of heights of left and // right subtrees plus 1 *height = max(lh, rh) + 1; return max(lh + rh + 1, max(ldiameter, rdiameter)); } // Helper function that allocates a new node with the // given data and NULL left and right pointers. struct node* newNode(int data) { struct node* node = (struct node*)malloc(sizeof(struct node)); node->data = data; node->left = NULL; node->right = NULL; return (node); } // Driver Code int main() { /* Constructed binary tree is 1 / \ 2 3 / \ 4 5 */ struct node* root = newNode(1); root->left = newNode(2); root->right = newNode(3); root->left->left = newNode(4); root->left->right = newNode(5); int height = 0; // Function Call cout << "Diameter of the given binary tree is " << diameterOpt(root, &height); return 0; } // This code is contributed by probinsah.
linear
linear
// Simple C++ program to find diameter // of a binary tree. #include <bits/stdc++.h> using namespace std; /* Tree node structure used in the program */ struct Node { int data; Node* left, *right; }; /* Function to find height of a tree */ int height(Node* root, int& ans) { if (root == NULL) return 0; int left_height = height(root->left, ans); int right_height = height(root->right, ans); // update the answer, because diameter of a // tree is nothing but maximum value of // (left_height + right_height + 1) for each node ans = max(ans, 1 + left_height + right_height); return 1 + max(left_height, right_height); } /* Computes the diameter of binary tree with given root. */ int diameter(Node* root) { if (root == NULL) return 0; int ans = INT_MIN; // This will store the final answer height(root, ans); return ans; } struct Node* newNode(int data) { struct Node* node = new Node; node->data = data; node->left = node->right = NULL; return (node); } // Driver code int main() { struct Node* root = newNode(1); root->left = newNode(2); root->right = newNode(3); root->left->left = newNode(4); root->left->right = newNode(5); printf("Diameter is %d\n", diameter(root)); return 0; }
logn
linear
// CPP program to find deepest right leaf // node of binary tree #include <bits/stdc++.h> using namespace std; // tree node struct Node { int data; Node *left, *right; }; // returns a new tree Node Node* newNode(int data) { Node* temp = new Node(); temp->data = data; temp->left = temp->right = NULL; return temp; } // return the deepest right leaf node // of binary tree Node* getDeepestRightLeafNode(Node* root) { if (!root) return NULL; // create a queue for level order traversal queue<Node*> q; q.push(root); Node* result = NULL; // traverse until the queue is empty while (!q.empty()) { Node* temp = q.front(); q.pop(); if (temp->left) { q.push(temp->left); } // Since we go level by level, the last // stored right leaf node is deepest one if (temp->right) { q.push(temp->right); if (!temp->right->left && !temp->right->right) result = temp->right; } } return result; } // driver program int main() { // construct a tree Node* root = newNode(1); root->left = newNode(2); root->right = newNode(3); root->left->right = newNode(4); root->right->left = newNode(5); root->right->right = newNode(6); root->right->left->right = newNode(7); root->right->right->right = newNode(8); root->right->left->right->left = newNode(9); root->right->right->right->right = newNode(10); Node* result = getDeepestRightLeafNode(root); if (result) cout << "Deepest Right Leaf Node :: " << result->data << endl; else cout << "No result, right leaf not found\n"; return 0; }
linear
linear
// A C++ program to find value of the deepest node // in a given binary tree #include <bits/stdc++.h> using namespace std; // A tree node struct Node { int data; struct Node *left, *right; }; // Utility function to create a new node Node *newNode(int data) { Node *temp = new Node; temp->data = data; temp->left = temp->right = NULL; return temp; } // maxLevel : keeps track of maximum level seen so far. // res : Value of deepest node so far. // level : Level of root void find(Node *root, int level, int &maxLevel, int &res) { if (root != NULL) { find(root->left, ++level, maxLevel, res); // Update level and rescue if (level > maxLevel) { res = root->data; maxLevel = level; } find(root->right, level, maxLevel, res); } } // Returns value of deepest node int deepestNode(Node *root) { // Initialize result and max level int res = -1; int maxLevel = -1; // Updates value "res" and "maxLevel" // Note that res and maxLen are passed // by reference. find(root, 0, maxLevel, res); return res; } // Driver program int main() { Node* root = newNode(1); root->left = newNode(2); root->right = newNode(3); root->left->left = newNode(4); root->right->left = newNode(5); root->right->right = newNode(6); root->right->left->right = newNode(7); root->right->right->right = newNode(8); root->right->left->right->left = newNode(9); cout << deepestNode(root); return 0; }
linear
linear
// A C++ program to find value of the // deepest node in a given binary tree #include <bits/stdc++.h> using namespace std; // A tree node with constructor class Node { public: int data; Node *left, *right; // constructor Node(int key) { data = key; left = NULL; right = NULL; } }; // Function to return the deepest node Node* deepestNode(Node* root) { Node* tmp = NULL; if (root == NULL) return NULL; // Creating a Queue queue<Node*> q; q.push(root); // Iterates until queue become empty while (q.size() > 0) { tmp = q.front(); q.pop(); if (tmp->left != NULL) q.push(tmp->left); if (tmp->right != NULL) q.push(tmp->right); } return tmp; } int main() { Node* root = new Node(1); root->left = new Node(2); root->right = new Node(3); root->left->left = new Node(4); root->right->left = new Node(5); root->right->right = new Node(6); root->right->left->right = new Node(7); root->right->right->right = new Node(8); root->right->left->right->left = new Node(9); Node* deepNode = deepestNode(root); cout << (deepNode->data); return 0; }
linear
linear
// CPP program to find deepest left leaf // node of binary tree #include <bits/stdc++.h> using namespace std; // tree node struct Node { int data; Node *left, *right; }; // returns a new tree Node Node* newNode(int data) { Node* temp = new Node(); temp->data = data; temp->left = temp->right = NULL; return temp; } // return the deepest left leaf node // of binary tree Node* getDeepestLeftLeafNode(Node* root) { if (!root) return NULL; // create a queue for level order traversal queue<Node*> q; q.push(root); Node* result = NULL; // traverse until the queue is empty while (!q.empty()) { Node* temp = q.front(); q.pop(); // Since we go level by level, the last // stored left leaf node is deepest one, if (temp->left) { q.push(temp->left); if (!temp->left->left && !temp->left->right) result = temp->left; } if (temp->right) q.push(temp->right); } return result; } // driver program int main() { // construct a tree Node* root = newNode(1); root->left = newNode(2); root->right = newNode(3); root->left->left = newNode(4); root->right->left = newNode(5); root->right->right = newNode(6); root->right->left->right = newNode(7); root->right->right->right = newNode(8); root->right->left->right->left = newNode(9); root->right->right->right->right = newNode(10); Node* result = getDeepestLeftLeafNode(root); if (result) cout << "Deepest Left Leaf Node :: " << result->data << endl; else cout << "No result, left leaf not found\n"; return 0; }
linear
linear
// C++ program to calculate width of binary tree #include <bits/stdc++.h> using namespace std; /* A binary tree node has data, pointer to left child and a pointer to right child */ class node { public: int data; node* left; node* right; node (int d){ this->data = d; this->left = this->right = NULL; } }; /*Function prototypes*/ int getWidth(node* root, int level); int height(node* node); /* Function to get the maximum width of a binary tree*/ int getMaxWidth(node* root) { int maxWidth = 0; int width; int h = height(root); int i; /* Get width of each level and compare the width with maximum width so far */ for (i = 1; i <= h; i++) { width = getWidth(root, i); if (width > maxWidth) maxWidth = width; } return maxWidth; } /* Get width of a given level */ int getWidth(node* root, int level) { if (root == NULL) return 0; if (level == 1) return 1; else if (level > 1) return getWidth(root->left, level - 1) + getWidth(root->right, level - 1); } /* UTILITY FUNCTIONS */ /* Compute the "height" of a tree -- the number of nodes along the longest path from the root node down to the farthest leaf node.*/ int height(node* node) { if (node == NULL) return 0; else { /* compute the height of each subtree */ int lHeight = height(node->left); int rHeight = height(node->right); /* use the larger one */ return (lHeight > rHeight) ? (lHeight + 1) : (rHeight + 1); } } /* Driver code*/ int main() { node* root = new node(1); root->left = new node(2); root->right = new node(3); root->left->left = new node(4); root->left->right = new node(5); root->right->right = new node(8); root->right->right->left = new node(6); root->right->right->right = new node(7); /* Constructed binary tree is: 1 / \ 2 3 / \ \ 4 5 8 / \ 6 7 */ // Function call cout << "Maximum width is " << getMaxWidth(root) << endl; return 0; } // This code is contributed by rathbhupendra
constant
quadratic
// A queue based C++ program to find maximum width // of a Binary Tree #include <bits/stdc++.h> using namespace std; /* A binary tree node has data, pointer to left child and a pointer to right child */ struct Node { int data; struct Node* left; struct Node* right; Node(int d) { this->data = d; this->left = this->right = NULL; } }; // Function to find the maximum width of the tree // using level order traversal int maxWidth(struct Node* root) { // Base case if (root == NULL) return 0; // Initialize result int result = 0; // Do Level order traversal keeping track of number // of nodes at every level. queue<Node*> q; q.push(root); while (!q.empty()) { // Get the size of queue when the level order // traversal for one level finishes int count = q.size(); // Update the maximum node count value result = max(count, result); // Iterate for all the nodes in the queue currently while (count--) { // Dequeue an node from queue Node* temp = q.front(); q.pop(); // Enqueue left and right children of // dequeued node if (temp->left != NULL) q.push(temp->left); if (temp->right != NULL) q.push(temp->right); } } return result; } // Driver code int main() { struct Node* root = new Node(1); root->left = new Node(2); root->right = new Node(3); root->left->left = new Node(4); root->left->right = new Node(5); root->right->right = new Node(8); root->right->right->left = new Node(6); root->right->right->right = new Node(7); /* Constructed Binary tree is: 1 / \ 2 3 / \ \ 4 5 8 / \ 6 7 */ // Function call cout << "Maximum width is " << maxWidth(root) << endl; return 0; } // This code is contributed by Nikhil Kumar // Singh(nickzuck_007)
np
linear
// C++ program to calculate width of binary tree #include <bits/stdc++.h> using namespace std; /* A binary tree node has data, pointer to left child and a pointer to right child */ class node { public: int data; node* left; node* right; node(int d) { this->data = d; this->left = this->right = NULL; } }; // A utility function to get // height of a binary tree int height(node* node); // A utility function that returns // maximum value in arr[] of size n int getMax(int arr[], int n); // A function that fills count array // with count of nodes at every // level of given binary tree void getMaxWidthRecur(node* root, int count[], int level); /* Function to get the maximum width of a binary tree*/ int getMaxWidth(node* root) { int width; int h = height(root); // Create an array that will // store count of nodes at each level int* count = new int[h]; int level = 0; // Fill the count array using preorder traversal getMaxWidthRecur(root, count, level); // Return the maximum value from count array return getMax(count, h); } // A function that fills count array // with count of nodes at every // level of given binary tree void getMaxWidthRecur(node* root, int count[], int level) { if (root) { count[level]++; getMaxWidthRecur(root->left, count, level + 1); getMaxWidthRecur(root->right, count, level + 1); } } /* UTILITY FUNCTIONS */ /* Compute the "height" of a tree -- the number of nodes along the longest path from the root node down to the farthest leaf node.*/ int height(node* node) { if (node == NULL) return 0; else { /* compute the height of each subtree */ int lHeight = height(node->left); int rHeight = height(node->right); /* use the larger one */ return (lHeight > rHeight) ? (lHeight + 1) : (rHeight + 1); } } // Return the maximum value from count array int getMax(int arr[], int n) { int max = arr[0]; int i; for (i = 0; i < n; i++) { if (arr[i] > max) max = arr[i]; } return max; } /* Driver code*/ int main() { node* root = new node(1); root->left = new node(2); root->right = new node(3); root->left->left = new node(4); root->left->right = new node(5); root->right->right = new node(8); root->right->right->left = new node(6); root->right->right->right = new node(7); cout << "Maximum width is " << getMaxWidth(root) << endl; return 0; } // This is code is contributed by rathbhupendra
logn
linear
// CPP program to print vertical width // of a tree #include <bits/stdc++.h> using namespace std; // A Binary Tree Node struct Node { int data; struct Node *left, *right; }; // get vertical width void lengthUtil(Node* root, int& maximum, int& minimum, int curr = 0) { if (root == NULL) return; // traverse left lengthUtil(root->left, maximum, minimum, curr - 1); // if curr is decrease then get // value in minimum if (minimum > curr) minimum = curr; // if curr is increase then get // value in maximum if (maximum < curr) maximum = curr; // traverse right lengthUtil(root->right, maximum, minimum, curr + 1); } int getLength(Node* root) { int maximum = 0, minimum = 0; lengthUtil(root, maximum, minimum, 0); // 1 is added to include root in the width return (abs(minimum) + maximum) + 1; } // Utility function to create a new tree node Node* newNode(int data) { Node* curr = new Node; curr->data = data; curr->left = curr->right = NULL; return curr; } // Driver program to test above functions int main() { Node* root = newNode(7); root->left = newNode(6); root->right = newNode(5); root->left->left = newNode(4); root->left->right = newNode(3); root->right->left = newNode(2); root->right->right = newNode(1); cout << getLength(root) << "\n"; return 0; }
logn
linear
// C++ program to find Vertical Height of a tree #include <bits/stdc++.h> #include <iostream> using namespace std; struct Node { int data; struct Node* left; struct Node* right; Node(int x) { data = x; left = right = NULL; } }; int verticalWidth(Node* root) { // Code here if (root == NULL) return 0; int maxLevel = 0, minLevel = 0; queue<pair<Node*, int> > q; q.push({ root, 0 }); // we take root as 0 // Level order traversal code while (q.empty() != true) { Node* cur = q.front().first; int count = q.front().second; q.pop(); if (cur->left) { minLevel = min(minLevel, count - 1); // as we go left, // level is decreased q.push({ cur->left, count - 1 }); } if (cur->right) { maxLevel = max(maxLevel, count + 1); // as we go right, // level is increased q.push({ cur->right, count + 1 }); } } return maxLevel + abs(minLevel) + 1; // +1 for the root node, we gave it a value // of zero } int main() { // making the tree Node* root = new Node(7); root->left = new Node(6); root->right = new Node(5); root->left->left = new Node(4); root->left->right = new Node(3); root->right->left = new Node(2); root->right->right = new Node(1); cout << "Vertical width is : " << verticalWidth(root) << endl; return 0; } // code contributed by Anshit Bansal
linear
linear
// CPP code to find vertical // width of a binary tree #include <bits/stdc++.h> using namespace std; // Tree class class Node { public : int data; Node *left, *right; // Constructor Node(int data_new) { data = data_new; left = right = NULL; } }; // Function to fill hd in set. void fillSet(Node* root, unordered_set<int>& s, int hd) { if (!root) return; fillSet(root->left, s, hd - 1); s.insert(hd); fillSet(root->right, s, hd + 1); } int verticalWidth(Node* root) { unordered_set<int> s; // Third parameter is horizontal // distance fillSet(root, s, 0); return s.size(); } int main() { Node* root = NULL; // Creating the above tree root = new Node(1); root->left = new Node(2); root->right = new Node(3); root->left->left = new Node(4); root->left->right = new Node(5); root->right->left = new Node(6); root->right->right = new Node(7); root->right->left->right = new Node(8); root->right->right->right = new Node(9); cout << verticalWidth(root) << "\n"; return 0; }
linear
linear
// CPP program to determine whether // vertical level l of binary tree // is sorted or not. #include <bits/stdc++.h> using namespace std; // Structure of a tree node. struct Node { int key; Node *left, *right; }; // Function to create new tree node. Node* newNode(int key) { Node* temp = new Node; temp->key = key; temp->left = temp->right = NULL; return temp; } // Helper function to determine if // vertical level l of given binary // tree is sorted or not. bool isSorted(Node* root, int level) { // If root is null, then the answer is an // empty subset and an empty subset is // always considered to be sorted. if (root == NULL) return true; // Variable to store previous // value in vertical level l. int prevVal = INT_MIN; // Variable to store current level // while traversing tree vertically. int currLevel; // Variable to store current node // while traversing tree vertically. Node* currNode; // Declare queue to do vertical order // traversal. A pair is used as element // of queue. The first element in pair // represents the node and the second // element represents vertical level // of that node. queue<pair<Node*, int> > q; // Insert root in queue. Vertical level // of root is 0. q.push(make_pair(root, 0)); // Do vertical order traversal until // all the nodes are not visited. while (!q.empty()) { currNode = q.front().first; currLevel = q.front().second; q.pop(); // Check if level of node extracted from // queue is required level or not. If it // is the required level then check if // previous value in that level is less // than or equal to value of node. if (currLevel == level) { if (prevVal <= currNode->key) prevVal = currNode->key; else return false; } // If left child is not NULL then push it // in queue with level reduced by 1. if (currNode->left) q.push(make_pair(currNode->left, currLevel - 1)); // If right child is not NULL then push it // in queue with level increased by 1. if (currNode->right) q.push(make_pair(currNode->right, currLevel + 1)); } // If the level asked is not present in the // given binary tree, that means that level // will contain an empty subset. Therefore answer // will be true. return true; } // Driver program int main() { /* 1 / \ 2 5 / \ 7 4 / 6 */ Node* root = newNode(1); root->left = newNode(2); root->right = newNode(5); root->left->left = newNode(7); root->left->right = newNode(4); root->left->right->left = newNode(6); int level = -1; if (isSorted(root, level) == true) cout << "Yes"; else cout << "No"; return 0; }
linear
linear
// CPP program to determine whether // binary tree is level sorted or not. #include <bits/stdc++.h> using namespace std; // Structure of a tree node. struct Node { int key; Node *left, *right; }; // Function to create new tree node. Node* newNode(int key) { Node* temp = new Node; temp->key = key; temp->left = temp->right = NULL; return temp; } // Function to determine if // given binary tree is level sorted // or not. int isSorted(Node* root) { // to store maximum value of previous // level. int prevMax = INT_MIN; // to store minimum value of current // level. int minval; // to store maximum value of current // level. int maxval; // to store number of nodes in current // level. int levelSize; // queue to perform level order traversal. queue<Node*> q; q.push(root); while (!q.empty()) { // find number of nodes in current // level. levelSize = q.size(); minval = INT_MAX; maxval = INT_MIN; // traverse current level and find // minimum and maximum value of // this level. while (levelSize > 0) { root = q.front(); q.pop(); levelSize--; minval = min(minval, root->key); maxval = max(maxval, root->key); if (root->left) q.push(root->left); if (root->right) q.push(root->right); } // if minimum value of this level // is not greater than maximum // value of previous level then // given tree is not level sorted. if (minval <= prevMax) return 0; // maximum value of this level is // previous maximum value for // next level. prevMax = maxval; } return 1; } // Driver program int main() { /* 1 / 4 \ 6 / \ 8 9 / \ 12 10 */ Node* root = newNode(1); root->left = newNode(4); root->left->right = newNode(6); root->left->right->left = newNode(8); root->left->right->right = newNode(9); root->left->right->left->left = newNode(12); root->left->right->right->right = newNode(10); if (isSorted(root)) cout << "Sorted"; else cout << "Not sorted"; return 0; }
linear
linear
// C++ Program to print Bottom View of Binary Tree #include<bits/stdc++.h> using namespace std; // Tree node class struct Node { int data; //data of the node int hd; //horizontal distance of the node Node *left, *right; //left and right references // Constructor of tree node Node(int key) { data = key; hd = INT_MAX; left = right = NULL; } }; // Method that prints the bottom view. void bottomView(Node *root) { if (root == NULL) return; // Initialize a variable 'hd' with 0 // for the root element. int hd = 0; // TreeMap which stores key value pair // sorted on key value map<int, int> m; // Queue to store tree nodes in level // order traversal queue<Node *> q; // Assign initialized horizontal distance // value to root node and add it to the queue. root->hd = hd; q.push(root); // In STL, push() is used enqueue an item // Loop until the queue is empty (standard // level order loop) while (!q.empty()) { Node *temp = q.front(); q.pop(); // In STL, pop() is used dequeue an item // Extract the horizontal distance value // from the dequeued tree node. hd = temp->hd; // Put the dequeued tree node to TreeMap // having key as horizontal distance. Every // time we find a node having same horizontal // distance we need to replace the data in // the map. m[hd] = temp->data; // If the dequeued node has a left child, add // it to the queue with a horizontal distance hd-1. if (temp->left != NULL) { temp->left->hd = hd-1; q.push(temp->left); } // If the dequeued node has a right child, add // it to the queue with a horizontal distance // hd+1. if (temp->right != NULL) { temp->right->hd = hd+1; q.push(temp->right); } } // Traverse the map elements using the iterator. for (auto i = m.begin(); i != m.end(); ++i) cout << i->second << " "; } // Driver Code int main() { Node *root = new Node(20); root->left = new Node(8); root->right = new Node(22); root->left->left = new Node(5); root->left->right = new Node(3); root->right->left = new Node(4); root->right->right = new Node(25); root->left->right->left = new Node(10); root->left->right->right = new Node(14); cout << "Bottom view of the given binary tree :\n"; bottomView(root); return 0; }
linear
nlogn
// C++ Program to print Bottom View of Binary Tree #include <bits/stdc++.h> #include <map> using namespace std; // Tree node class struct Node { // data of the node int data; // horizontal distance of the node int hd; //left and right references Node * left, * right; // Constructor of tree node Node(int key) { data = key; hd = INT_MAX; left = right = NULL; } }; void printBottomViewUtil(Node * root, int curr, int hd, map <int, pair <int, int>> & m) { // Base case if (root == NULL) return; // If node for a particular // horizontal distance is not // present, add to the map. if (m.find(hd) == m.end()) { m[hd] = make_pair(root -> data, curr); } // Compare height for already // present node at similar horizontal // distance else { pair < int, int > p = m[hd]; if (p.second <= curr) { m[hd].second = curr; m[hd].first = root -> data; } } // Recur for left subtree printBottomViewUtil(root -> left, curr + 1, hd - 1, m); // Recur for right subtree printBottomViewUtil(root -> right, curr + 1, hd + 1, m); } void printBottomView(Node * root) { // Map to store Horizontal Distance, // Height and Data. map < int, pair < int, int > > m; printBottomViewUtil(root, 0, 0, m); // Prints the values stored by printBottomViewUtil() map < int, pair < int, int > > ::iterator it; for (it = m.begin(); it != m.end(); ++it) { pair < int, int > p = it -> second; cout << p.first << " "; } } int main() { Node * root = new Node(20); root -> left = new Node(8); root -> right = new Node(22); root -> left -> left = new Node(5); root -> left -> right = new Node(3); root -> right -> left = new Node(4); root -> right -> right = new Node(25); root -> left -> right -> left = new Node(10); root -> left -> right -> right = new Node(14); cout << "Bottom view of the given binary tree :\n"; printBottomView(root); return 0; }
linear
nlogn
#include <bits/stdc++.h> using namespace std; // Tree node class struct Node { // data of the node int data; // horizontal distance of the node int hd; //left and right references Node * left, * right; // Constructor of tree node Node(int key) { data = key; hd = INT_MAX; left = right = NULL; } }; void printBottomView(Node * root) { if(!root) return ;//if root is NULL unordered_map<int,int> hash; // <vertical_index , root->data> int leftmost = 0; // to store the leftmost index so that we move from left to right queue<pair<Node*,int>> q; // pair<Node*,vertical Index> for level order traversal. q.push({root,0}); // push the root and 0 vertial index while(!q.empty()){ auto top = q.front(); // store q.front() in top variable q.pop(); Node *temp = top.first; // store the Node in temp for left and right nodes int ind = top.second; // store the vertical index of current node hash[ind] = temp->data; // store the latest vertical_index(key) -> root->data(value) leftmost = min(ind,leftmost); // have the leftmost vertical index if(temp->left){ q.push({temp->left,ind-1});}// check if any node of left then go in negative direction if(temp->right){ q.push({temp->right,ind+1});} //check if any node of left then go in positive direction } //teverse each value in hash from leftmost to positive side till key is available while(hash.find(leftmost)!=hash.end()){ cout<<hash[leftmost++]<<" "; } } int main() { Node * root = new Node(20); root -> left = new Node(8); root -> right = new Node(22); root -> left -> left = new Node(5); root -> left -> right = new Node(3); root -> right -> left = new Node(4); root -> right -> right = new Node(25); root -> left -> right -> left = new Node(10); root -> left -> right -> right = new Node(14); cout << "Bottom view of the given binary tree :\n"; printBottomView(root); return 0; }
linear
linear
// C++ program to count half nodes in a Binary Tree #include <bits/stdc++.h> using namespace std; // A binary tree Node has data, pointer to left // child and a pointer to right child struct Node { int data; struct Node* left, *right; }; // Function to get the count of half Nodes in // a binary tree unsigned int gethalfCount(struct Node* node) { // If tree is empty if (!node) return 0; int count = 0; // Initialize count of half nodes // Do level order traversal starting from root queue<Node *> q; q.push(node); while (!q.empty()) { struct Node *temp = q.front(); q.pop(); if (!temp->left && temp->right || temp->left && !temp->right) count++; if (temp->left != NULL) q.push(temp->left); if (temp->right != NULL) q.push(temp->right); } return count; } /* Helper function that allocates a new Node with the given data and NULL left and right pointers. */ struct Node* newNode(int data) { struct Node* node = new Node; node->data = data; node->left = node->right = NULL; return (node); } // Driver program int main(void) { /* 2 / \ 7 5 \ \ 6 9 / \ / 1 11 4 Let us create Binary Tree shown in above example */ struct Node *root = newNode(2); root->left = newNode(7); root->right = newNode(5); root->left->right = newNode(6); root->left->right->left = newNode(1); root->left->right->right = newNode(11); root->right->right = newNode(9); root->right->right->left = newNode(4); cout << gethalfCount(root); return 0; }
linear
linear
// C++ program to count half nodes in a Binary Tree #include <bits/stdc++.h> using namespace std; // A binary tree Node has data, pointer to left // child and a pointer to right child struct Node { int data; struct Node* left, *right; }; // Function to get the count of half Nodes in // a binary tree unsigned int gethalfCount(struct Node* root) { if (root == NULL) return 0; int res = 0; if ((root->left == NULL && root->right != NULL) || (root->left != NULL && root->right == NULL)) res++; res += (gethalfCount(root->left) + gethalfCount(root->right)); return res; } /* Helper function that allocates a new Node with the given data and NULL left and right pointers. */ struct Node* newNode(int data) { struct Node* node = new Node; node->data = data; node->left = node->right = NULL; return (node); } // Driver program int main(void) { /* 2 / \ 7 5 \ \ 6 9 / \ / 1 11 4 Let us create Binary Tree shown in above example */ struct Node *root = newNode(2); root->left = newNode(7); root->right = newNode(5); root->left->right = newNode(6); root->left->right->left = newNode(1); root->left->right->right = newNode(11); root->right->right = newNode(9); root->right->right->left = newNode(4); cout << gethalfCount(root); return 0; }
linear
linear
// C++ program to count // full nodes in a Binary Tree #include <bits/stdc++.h> using namespace std; // A binary tree Node has data, pointer to left // child and a pointer to right child struct Node { int data; struct Node* left, *right; }; // Function to get the count of full Nodes in // a binary tree unsigned int getfullCount(struct Node* node) { // If tree is empty if (!node) return 0; queue<Node *> q; // Do level order traversal starting from root int count = 0; // Initialize count of full nodes q.push(node); while (!q.empty()) { struct Node *temp = q.front(); q.pop(); if (temp->left && temp->right) count++; if (temp->left != NULL) q.push(temp->left); if (temp->right != NULL) q.push(temp->right); } return count; } /* Helper function that allocates a new Node with the given data and NULL left and right pointers. */ struct Node* newNode(int data) { struct Node* node = new Node; node->data = data; node->left = node->right = NULL; return (node); } // Driver program int main(void) { /* 2 / \ 7 5 \ \ 6 9 / \ / 1 11 4 Let us create Binary Tree as shown */ struct Node *root = newNode(2); root->left = newNode(7); root->right = newNode(5); root->left->right = newNode(6); root->left->right->left = newNode(1); root->left->right->right = newNode(11); root->right->right = newNode(9); root->right->right->left = newNode(4); cout << getfullCount(root); return 0; }
linear
linear
// C++ program to count full nodes in a Binary Tree #include <bits/stdc++.h> using namespace std; // A binary tree Node has data, pointer to left // child and a pointer to right child struct Node { int data; struct Node* left, *right; }; // Function to get the count of full Nodes in // a binary tree unsigned int getfullCount(struct Node* root) { if (root == NULL) return 0; int res = 0; if (root->left && root->right) res++; res += (getfullCount(root->left) + getfullCount(root->right)); return res; } /* Helper function that allocates a new Node with the given data and NULL left and right pointers. */ struct Node* newNode(int data) { struct Node* node = new Node; node->data = data; node->left = node->right = NULL; return (node); } // Driver program int main(void) { /* 2 / \ 7 5 \ \ 6 9 / \ / 1 11 4 Let us create Binary Tree as shown */ struct Node *root = newNode(2); root->left = newNode(7); root->right = newNode(5); root->left->right = newNode(6); root->left->right->left = newNode(1); root->left->right->right = newNode(11); root->right->right = newNode(9); root->right->right->left = newNode(4); cout << getfullCount(root); return 0; }
linear
linear
// Connect nodes at same level using level order // traversal. #include <bits/stdc++.h> using namespace std; struct Node { int data; struct Node* left, *right, *nextRight; }; // Sets nextRight of all nodes of a tree void connect(struct Node* root) { queue<Node*> q; q.push(root); // null marker to represent end of current level q.push(NULL); // Do Level order of tree using NULL markers while (!q.empty()) { Node *p = q.front(); q.pop(); if (p != NULL) { // next element in queue represents next // node at current Level p->nextRight = q.front(); // push left and right children of current // node if (p->left) q.push(p->left); if (p->right) q.push(p->right); } // if queue is not empty, push NULL to mark // nodes at this level are visited else if (!q.empty()) q.push(NULL); } } /* UTILITY FUNCTIONS */ /* Helper function that allocates a new node with the given data and NULL left and right pointers. */ struct Node* newnode(int data) { struct Node* node = (struct Node*) malloc(sizeof(struct Node)); node->data = data; node->left = node->right = node->nextRight = NULL; return (node); } /* Driver program to test above functions*/ int main() { /* Constructed binary tree is 10 / \ 8 2 / \ 3 90 */ struct Node* root = newnode(10); root->left = newnode(8); root->right = newnode(2); root->left->left = newnode(3); root->right->right = newnode(90); // Populates nextRight pointer in all nodes connect(root); // Let us check the values of nextRight pointers printf("Following are populated nextRight pointers in \n" "the tree (-1 is printed if there is no nextRight) \n"); printf("nextRight of %d is %d \n", root->data, root->nextRight ? root->nextRight->data : -1); printf("nextRight of %d is %d \n", root->left->data, root->left->nextRight ? root->left->nextRight->data : -1); printf("nextRight of %d is %d \n", root->right->data, root->right->nextRight ? root->right->nextRight->data : -1); printf("nextRight of %d is %d \n", root->left->left->data, root->left->left->nextRight ? root->left->left->nextRight->data : -1); printf("nextRight of %d is %d \n", root->right->right->data, root->right->right->nextRight ? root->right->right->nextRight->data : -1); return 0; }
linear
linear
// Iterative CPP program to connect // nodes at same level using // constant extra space #include<bits/stdc++.h> #include<bits/stdc++.h> using namespace std; class node { public: int data; node* left; node* right; node *nextRight; /* Constructor that allocates a new node with the given data and NULL left and right pointers. */ node(int data) { this->data = data; this->left = NULL; this->right = NULL; this->nextRight = NULL; } }; /* This function returns the leftmost child of nodes at the same level as p. This function is used to getNExt right of p's right child If right child of is NULL then this can also be used for the left child */ node *getNextRight(node *p) { node *temp = p->nextRight; /* Traverse nodes at p's level and find and return the first node's first child */ while (temp != NULL) { if (temp->left != NULL) return temp->left; if (temp->right != NULL) return temp->right; temp = temp->nextRight; } // If all the nodes at p's level // are leaf nodes then return NULL return NULL; } /* Sets nextRight of all nodes of a tree with root as p */ void connectRecur(node* p) { node *temp; if (!p) return; // Set nextRight for root p->nextRight = NULL; // set nextRight of all levels one by one while (p != NULL) { node *q = p; /* Connect all children nodes of p and children nodes of all other nodes at same level as p */ while (q != NULL) { // Set the nextRight pointer // for p's left child if (q->left) { // If q has right child, then // right child is nextRight of // p and we also need to set // nextRight of right child if (q->right) q->left->nextRight = q->right; else q->left->nextRight = getNextRight(q); } if (q->right) q->right->nextRight = getNextRight(q); // Set nextRight for other // nodes in pre order fashion q = q->nextRight; } // start from the first // node of next level if (p->left) p = p->left; else if (p->right) p = p->right; else p = getNextRight(p); } } /* Driver code*/ int main() { /* Constructed binary tree is 10 / \ 8 2 / \ 3 90 */ node *root = new node(10); root->left = new node(8); root->right = new node(2); root->left->left = new node(3); root->right->right = new node(90); // Populates nextRight pointer in all nodes connectRecur(root); // Let us check the values of nextRight pointers cout << "Following are populated nextRight pointers in the tree" " (-1 is printed if there is no nextRight) \n"; cout << "nextRight of " << root->data << " is " << (root->nextRight? root->nextRight->data: -1) <<endl; cout << "nextRight of " << root->left->data << " is " << (root->left->nextRight? root->left->nextRight->data: -1) << endl; cout << "nextRight of " << root->right->data << " is " << (root->right->nextRight? root->right->nextRight->data: -1) << endl; cout << "nextRight of " << root->left->left->data<< " is " << (root->left->left->nextRight? root->left->left->nextRight->data: -1) << endl; cout << "nextRight of " << root->right->right->data << " is " << (root->right->right->nextRight? root->right->right->nextRight->data: -1) << endl; return 0; } // This code is contributed by rathbhupendra
constant
linear
/* Iterative program to connect all the adjacent nodes at * the same level in a binary tree*/ #include <iostream> #include <queue> using namespace std; // A Binary Tree Node class node { public: int data; node* left; node* right; node* nextRight; /* Constructor that allocates a new node with the given data and NULL left and right pointers. */ node(int data) { this->data = data; this->left = NULL; this->right = NULL; this->nextRight = NULL; } }; // setting right pointer to next right node /* 10 ----------> NULL / \ 8 --->2 --------> NULL / 3 ----------------> NULL */ void connect(node* root) { // Base condition if (root == NULL) return; // Create an empty queue like level order traversal queue<node*> q; q.push(root); while (!q.empty()) { // size indicates no. of nodes at current level int size = q.size(); // for keeping track of previous node node* prev = NULL; while (size--) { node* temp = q.front(); q.pop(); if (temp->left) q.push(temp->left); if (temp->right) q.push(temp->right); if (prev != NULL) prev->nextRight = temp; prev = temp; } prev->nextRight = NULL; } } int main() { /* Constructed binary tree is 10 / \ 8 2 / 3 */ // Let us create binary tree shown above node* root = new node(10); root->left = new node(8); root->right = new node(2); root->left->left = new node(3); connect(root); // Let us check the values // of nextRight pointers cout << "Following are populated nextRight pointers in " "the tree" " (-1 is printed if there is no nextRight)\n"; cout << "nextRight of " << root->data << " is " << (root->nextRight ? root->nextRight->data : -1) << endl; cout << "nextRight of " << root->left->data << " is " << (root->left->nextRight ? root->left->nextRight->data : -1) << endl; cout << "nextRight of " << root->right->data << " is " << (root->right->nextRight ? root->right->nextRight->data : -1) << endl; cout << "nextRight of " << root->left->left->data << " is " << (root->left->left->nextRight ? root->left->left->nextRight->data : -1) << endl; return 0; } // this code is contributed by Kapil Poonia
linear
linear
// C++ implementation to find the level // having maximum number of Nodes #include <bits/stdc++.h> using namespace std; /* A binary tree Node has data, pointer to left child and a pointer to right child */ struct Node { int data; struct Node* left; struct Node* right; }; /* Helper function that allocates a new node with the given data and NULL left and right pointers. */ struct Node* newNode(int data) { struct Node* node = new Node; node->data = data; node->left = NULL; node->right = NULL; return(node); } // function to find the level // having maximum number of Nodes int maxNodeLevel(Node *root) { if (root == NULL) return -1; queue<Node *> q; q.push(root); // Current level int level = 0; // Maximum Nodes at same level int max = INT_MIN; // Level having maximum Nodes int level_no = 0; while (1) { // Count Nodes in a level int NodeCount = q.size(); if (NodeCount == 0) break; // If it is maximum till now // Update level_no to current level if (NodeCount > max) { max = NodeCount; level_no = level; } // Pop complete current level while (NodeCount > 0) { Node *Node = q.front(); q.pop(); if (Node->left != NULL) q.push(Node->left); if (Node->right != NULL) q.push(Node->right); NodeCount--; } // Increment for next level level++; } return level_no; } // Driver program to test above int main() { // binary tree formation struct Node *root = newNode(2); /* 2 */ root->left = newNode(1); /* / \ */ root->right = newNode(3); /* 1 3 */ root->left->left = newNode(4); /* / \ \ */ root->left->right = newNode(6); /* 4 6 8 */ root->right->right = newNode(8); /* / */ root->left->right->left = newNode(5);/* 5 */ printf("Level having maximum number of Nodes : %d", maxNodeLevel(root)); return 0; }
linear
linear
// C++ code for the above approach #include <bits/stdc++.h> using namespace std; // A binary tree node has data, pointer to // left child and a pointer to right child struct Node { int val; struct Node *left, *right; }; // Initialising a map with key as levels of the tree map<int, pair<double, double> > mp; void avg(Node* r, int l) { // If the node is NULL if (r == NULL) return; // Add the current value to the sum of this level mp[l].first += r->val; // Increase the number of elements in the current level mp[l].second++; // Traverse left avg(r->left, l + 1); // Traverse right avg(r->right, l + 1); } void averageOfLevels(Node* root) { avg(root, 0); // Travaersing for levels in map for (auto i : mp) { // Printing average of all levels cout << (i.second.first / i.second.second) << ' '; } } // Function to create a new node Node* newNode(int data) { Node* temp = new Node; temp->val = data; temp->left = temp->right = NULL; return temp; } int main() { /* Let us construct a Binary Tree 4 / \ 2 9 / \ \ 3 5 7 */ Node* root = NULL; root = newNode(4); root->left = newNode(2); root->right = newNode(9); root->left->left = newNode(3); root->left->right = newNode(8); root->right->right = newNode(7); // Function Call averageOfLevels(root); } // This Code has been contributed by Alok Khansali
logn
nlogn
// C++ implementation to print largest // value in each level of Binary Tree #include <bits/stdc++.h> using namespace std; // structure of a node of binary tree struct Node { int data; Node *left, *right; }; // function to get a new node Node* newNode(int data) { // allocate space Node* temp = new Node; // put in the data temp->data = data; temp->left = temp->right = NULL; return temp; } // function to print largest value // in each level of Binary Tree void largestValueInEachLevel(Node* root) { // if tree is empty if (!root) return; queue<Node*> q; int nc, max; // push root to the queue 'q' q.push(root); while (1) { // node count for the current level nc = q.size(); // if true then all the nodes of // the tree have been traversed if (nc == 0) break; // maximum element for the current // level max = INT_MIN; while (nc--) { // get the front element from 'q' Node* front = q.front(); // remove front element from 'q' q.pop(); // if true, then update 'max' if (max < front->data) max = front->data; // if left child exists if (front->left) q.push(front->left); // if right child exists if (front->right) q.push(front->right); } // print maximum element of // current level cout << max << " "; } } // Driver code int main() { /* Construct a Binary Tree 4 / \ 9 2 / \ \ 3 5 7 */ Node* root = NULL; root = newNode(4); root->left = newNode(9); root->right = newNode(2); root->left->left = newNode(3); root->left->right = newNode(5); root->right->right = newNode(7); // Function call largestValueInEachLevel(root); return 0; }
constant
linear
// C++ program to Get Level of a node in a Binary Tree #include <bits/stdc++.h> using namespace std; /* A tree node structure */ struct node { int data; struct node* left; struct node* right; }; // Helper function for getLevel(). It returns level of the // data if data is present in tree, otherwise returns 0. int getLevelUtil(struct node* node, int data, int level) { if (node == NULL) return 0; if (node->data == data) return level; int downlevel = getLevelUtil(node->left, data, level + 1); if (downlevel != 0) return downlevel; downlevel = getLevelUtil(node->right, data, level + 1); return downlevel; } /* Returns level of given data value */ int getLevel(struct node* node, int data) { return getLevelUtil(node, data, 1); } // Utility function to create a new Binary Tree node struct node* newNode(int data) { struct node* temp = new struct node; temp->data = data; temp->left = NULL; temp->right = NULL; return temp; } // Driver Code int main() { struct node* root = new struct node; int x; // Constructing tree given in the above figure root = newNode(3); root->left = newNode(2); root->right = newNode(5); root->left->left = newNode(1); root->left->right = newNode(4); for (x = 1; x <= 5; x++) { int level = getLevel(root, x); if (level) cout << "Level of " << x << " is " << level << endl; else cout << x << "is not present in tree" << endl; } getchar(); return 0; } // This code is contributed by Aditya Kumar (adityakumar129)
linear
linear
// C++ program to print level in which X is present in // binary tree using STL #include <bits/stdc++.h> using namespace std; // A Binary Tree Node struct Node { int data; struct Node *left, *right; }; int printLevel(Node* root, int X) { Node* node; // Base Case if (root == NULL) return 0; // Create an empty queue for level order traversal queue<Node*> q; // Create a var represent current level of tree int currLevel = 1; // Enqueue Root q.push(root); while (q.empty() == false) { int size = q.size(); while (size--) { node = q.front(); if (node->data == X) return currLevel; q.pop(); /* Enqueue left child */ if (node->left != NULL) q.push(node->left); /*Enqueue right child */ if (node->right != NULL) q.push(node->right); } currLevel++; } return 0; } // Utility function to create a new tree node Node* newNode(int data) { Node* temp = new Node; temp->data = data; temp->left = temp->right = NULL; return temp; } // Driver program to test above functions int main() { // Let us create binary tree shown in above diagram Node* root = newNode(1); root->left = newNode(2); root->right = newNode(3); root->left->left = newNode(4); root->left->right = newNode(5); root->right->left = newNode(7); root->right->right = newNode(6); cout << printLevel(root, 6); return 0; } // This code is contributed by Aditya Kumar (adityakumar129)
linear
linear
// CPP program to print level of given node // in binary tree iterative approach /* Example binary tree root is at level 1 20 / \ 10 30 / \ / \ 5 15 25 40 / 12 */ #include <bits/stdc++.h> using namespace std; // node of binary tree struct node { int data; node* left; node* right; }; // utility function to create // a new node node* getnode(int data) { node* newnode = new node(); newnode->data = data; newnode->left = NULL; newnode->right = NULL; } // utility function to return level of given node int getlevel(node* root, int data) { queue<node*> q; int level = 1; q.push(root); // extra NULL is pushed to keep track // of all the nodes to be pushed before // level is incremented by 1 q.push(NULL); while (!q.empty()) { node* temp = q.front(); q.pop(); if (temp == NULL) { if (q.front() != NULL) { q.push(NULL); } level += 1; } else { if (temp->data == data) { return level; } if (temp->left) { q.push(temp->left); } if (temp->right) { q.push(temp->right); } } } return 0; } int main() { // create a binary tree node* root = getnode(20); root->left = getnode(10); root->right = getnode(30); root->left->left = getnode(5); root->left->right = getnode(15); root->left->right->left = getnode(12); root->right->left = getnode(25); root->right->right = getnode(40); // return level of node int level = getlevel(root, 30); (level != 0) ? (cout << "level of node 30 is " << level << endl) : (cout << "node 30 not found" << endl); level = getlevel(root, 12); (level != 0) ? (cout << "level of node 12 is " << level << endl) : (cout << "node 12 not found" << endl); level = getlevel(root, 25); (level != 0) ? (cout << "level of node 25 is " << level << endl) : (cout << "node 25 not found" << endl); level = getlevel(root, 27); (level != 0) ? (cout << "level of node 27 is " << level << endl) : (cout << "node 27 not found" << endl); return 0; }
linear
linear
// C++ program to remove all half nodes #include <bits/stdc++.h> using namespace std; struct node { int data; struct node* left, *right; }; struct node* newNode(int data) { node* nod = new node(); nod->data = data; nod->left = nod->right = NULL; return(nod); } void printInoder(struct node*root) { if (root != NULL) { printInoder(root->left); cout<< root->data << " "; printInoder(root->right); } } // Removes all nodes with only one child and returns // new root (note that root may change) struct node* RemoveHalfNodes(struct node* root) { if (root==NULL) return NULL; root->left = RemoveHalfNodes(root->left); root->right = RemoveHalfNodes(root->right); if (root->left==NULL && root->right==NULL) return root; /* if current nodes is a half node with left child NULL left, then it's right child is returned and replaces it in the given tree */ if (root->left==NULL) { struct node *new_root = root->right; free(root); // To avoid memory leak return new_root; } /* if current nodes is a half node with right child NULL right, then it's right child is returned and replaces it in the given tree */ if (root->right==NULL) { struct node *new_root = root->left; free(root); // To avoid memory leak return new_root; } return root; } // Driver program int main(void) { struct node*NewRoot=NULL; struct node *root = newNode(2); root->left = newNode(7); root->right = newNode(5); root->left->right = newNode(6); root->left->right->left=newNode(1); root->left->right->right=newNode(11); root->right->right=newNode(9); root->right->right->left=newNode(4); cout<<"Inorder traversal of given tree \n"; printInoder(root); NewRoot = RemoveHalfNodes(root); cout<<"\nInorder traversal of the modified tree \n"; printInoder(NewRoot); return 0; }
constant
linear
/* C++ program to pairwise swap leaf nodes from left to right */ #include <bits/stdc++.h> using namespace std; // A Binary Tree Node struct Node { int data; struct Node *left, *right; }; // function to swap two Node void Swap(Node **a, Node **b) { Node * temp = *a; *a = *b; *b = temp; } // two pointers to keep track of // first and second nodes in a pair Node **firstPtr; Node **secondPtr; // function to pairwise swap leaf // nodes from left to right void pairwiseSwap(Node **root, int &count) { // if node is null, return if (!(*root)) return; // if node is leaf node, increment count if(!(*root)->left&&!(*root)->right) { // initialize second pointer // by current node secondPtr = root; // increment count count++; // if count is even, swap first // and second pointers if (count%2 == 0) Swap(firstPtr, secondPtr); else // if count is odd, initialize // first pointer by second pointer firstPtr = secondPtr; } // if left child exists, check for leaf // recursively if ((*root)->left) pairwiseSwap(&(*root)->left, count); // if right child exists, check for leaf // recursively if ((*root)->right) pairwiseSwap(&(*root)->right, count); } // Utility function to create a new tree node Node* newNode(int data) { Node *temp = new Node; temp->data = data; temp->left = temp->right = NULL; return temp; } // function to print inorder traversal // of binary tree void printInorder(Node* node) { if (node == NULL) return; /* first recur on left child */ printInorder(node->left); /* then print the data of node */ printf("%d ", node->data); /* now recur on right child */ printInorder(node->right); } // Driver program to test above functions int main() { // Let us create binary tree shown in // above diagram Node *root = newNode(1); root->left = newNode(2); root->right = newNode(3); root->left->left = newNode(4); root->right->left = newNode(5); root->right->right = newNode(8); root->right->left->left = newNode(6); root->right->left->right = newNode(7); root->right->right->left = newNode(9); root->right->right->right = newNode(10); // print inorder traversal before swapping cout << "Inorder traversal before swap:\n"; printInorder(root); cout << "\n"; // variable to keep track // of leafs traversed int c = 0; // Pairwise swap of leaf nodes pairwiseSwap(&root, c); // print inorder traversal after swapping cout << "Inorder traversal after swap:\n"; printInorder(root); cout << "\n"; return 0; }
linear
linear
// C++ program to find the length of longest // path with same values in a binary tree. #include <bits/stdc++.h> using namespace std; /* A binary tree node has data, pointer to left child and a pointer to right child */ struct Node { int val; struct Node *left, *right; }; /* Function to print the longest path of same values */ int length(Node *node, int *ans) { if (!node) return 0; // Recursive calls to check for subtrees int left = length(node->left, ans); int right = length(node->right, ans); // Variables to store maximum lengths in two directions int Leftmax = 0, Rightmax = 0; // If curr node and it's left child has same value if (node->left && node->left->val == node->val) Leftmax += left + 1; // If curr node and it's right child has same value if (node->right && node->right->val == node->val) Rightmax += right + 1; *ans = max(*ans, Leftmax + Rightmax); return max(Leftmax, Rightmax); } /* Driver function to find length of longest same value path*/ int longestSameValuePath(Node *root) { int ans = 0; length(root, &ans); return ans; } /* Helper function that allocates a new node with the given data and NULL left and right pointers. */ Node *newNode(int data) { Node *temp = new Node; temp->val = data; temp->left = temp->right = NULL; return temp; } // Driver code int main() { /* Let us construct a Binary Tree 4 / \ 4 4 / \ \ 4 9 5 */ Node *root = NULL; root = newNode(4); root->left = newNode(4); root->right = newNode(4); root->left->left = newNode(4); root->left->right = newNode(9); root->right->right = newNode(5); cout << longestSameValuePath(root); return 0; }
logn
linear
// C++ program to find distance of a given // node from root. #include <bits/stdc++.h> using namespace std; // A Binary Tree Node struct Node { int data; Node *left, *right; }; // A utility function to create a new Binary // Tree Node Node *newNode(int item) { Node *temp = new Node; temp->data = item; temp->left = temp->right = NULL; return temp; } // Returns -1 if x doesn't exist in tree. Else // returns distance of x from root int findDistance(Node *root, int x) { // Base case if (root == NULL) return -1; // Initialize distance int dist = -1; // Check if x is present at root or in left // subtree or right subtree. if ((root->data == x) || (dist = findDistance(root->left, x)) >= 0 || (dist = findDistance(root->right, x)) >= 0) return dist + 1; return dist; } // Driver Program to test above functions int main() { Node *root = newNode(5); root->left = newNode(10); root->right = newNode(15); root->left->left = newNode(20); root->left->right = newNode(25); root->left->right->right = newNode(45); root->right->left = newNode(30); root->right->right = newNode(35); cout << findDistance(root, 45); return 0; }
constant
linear
// C program to print right sibling of a node #include <bits/stdc++.h> // A Binary Tree Node struct Node { int data; Node *left, *right, *parent; }; // A utility function to create a new Binary // Tree Node Node* newNode(int item, Node* parent) { Node* temp = new Node; temp->data = item; temp->left = temp->right = NULL; temp->parent = parent; return temp; } // Method to find right sibling Node* findRightSibling(Node* node, int level) { if (node == NULL || node->parent == NULL) return NULL; // GET Parent pointer whose right child is not // a parent or itself of this node. There might // be case when parent has no right child, but, // current node is left child of the parent // (second condition is for that). while (node->parent->right == node || (node->parent->right == NULL && node->parent->left == node)) { if (node->parent == NULL || node->parent->parent == NULL) return NULL; node = node->parent; level--; } // Move to the required child, where right sibling // can be present node = node->parent->right; if (node == NULL) return NULL; // find right sibling in the given subtree(from current // node), when level will be 0 while (level < 0) { // Iterate through subtree if (node->left != NULL) node = node->left; else if (node->right != NULL) node = node->right; else // if no child are there, we cannot have right // sibling in this path break; level++; } if (level == 0) return node; // This is the case when we reach 9 node in the tree, // where we need to again recursively find the right // sibling return findRightSibling(node, level); } // Driver Program to test above functions int main() { Node* root = newNode(1, NULL); root->left = newNode(2, root); root->right = newNode(3, root); root->left->left = newNode(4, root->left); root->left->right = newNode(6, root->left); root->left->left->left = newNode(7, root->left->left); root->left->left->left->left = newNode(10, root->left->left->left); root->left->right->right = newNode(9, root->left->right); root->right->right = newNode(5, root->right); root->right->right->right = newNode(8, root->right->right); root->right->right->right->right = newNode(12, root->right->right->right); // passing 10 Node* res = findRightSibling(root->left->left->left->left, 0); if (res == NULL) printf("No right sibling"); else printf("%d", res->data); return 0; }
constant
linear
/* C++ program to find next right of a given key using preorder traversal */ #include <bits/stdc++.h> using namespace std; // A Binary Tree Node struct Node { struct Node *left, *right; int key; }; // Utility function to create a new tree node Node* newNode(int key) { Node* temp = new Node; temp->key = key; temp->left = temp->right = NULL; return temp; } // Function to find next node for given node // in same level in a binary tree by using // pre-order traversal Node* nextRightNode(Node* root, int k, int level, int& value_level) { // return null if tree is empty if (root == NULL) return NULL; // if desired node is found, set value_level // to current level if (root->key == k) { value_level = level; return NULL; } // if value_level is already set, then current // node is the next right node else if (value_level) { if (level == value_level) return root; } // recurse for left subtree by increasing level by 1 Node* leftNode = nextRightNode(root->left, k, level + 1, value_level); // if node is found in left subtree, return it if (leftNode) return leftNode; // recurse for right subtree by increasing level by 1 return nextRightNode(root->right, k, level + 1, value_level); } // Function to find next node of given node in the // same level in given binary tree Node* nextRightNodeUtil(Node* root, int k) { int value_level = 0; return nextRightNode(root, k, 1, value_level); } // A utility function to test above functions void test(Node* root, int k) { Node* nr = nextRightNodeUtil(root, k); if (nr != NULL) cout << "Next Right of " << k << " is " << nr->key << endl; else cout << "No next right node found for " << k << endl; } // Driver program to test above functions int main() { // Let us create binary tree given in the // above example Node* root = newNode(10); root->left = newNode(2); root->right = newNode(6); root->right->right = newNode(5); root->left->left = newNode(8); root->left->right = newNode(4); test(root, 10); test(root, 2); test(root, 6); test(root, 5); test(root, 8); test(root, 4); return 0; }
constant
linear
// CPP Program to find Tilt of Binary Tree #include <bits/stdc++.h> using namespace std; /* A binary tree node has data, pointer to left child and a pointer to right child */ struct Node { int val; struct Node *left, *right; }; /* Recursive function to calculate Tilt of whole tree */ int traverse(Node* root, int* tilt) { if (!root) return 0; // Compute tilts of left and right subtrees // and find sums of left and right subtrees int left = traverse(root->left, tilt); int right = traverse(root->right, tilt); // Add current tilt to overall *tilt += abs(left - right); // Returns sum of nodes under current tree return left + right + root->val; } /* Driver function to print Tilt of whole tree */ int Tilt(Node* root) { int tilt = 0; traverse(root, &tilt); return tilt; } /* Helper function that allocates a new node with the given data and NULL left and right pointers. */ Node* newNode(int data) { Node* temp = new Node; temp->val = data; temp->left = temp->right = NULL; return temp; } // Driver code int main() { /* Let us construct a Binary Tree 4 / \ 2 9 / \ \ 3 5 7 */ Node* root = NULL; root = newNode(4); root->left = newNode(2); root->right = newNode(9); root->left->left = newNode(3); root->left->right = newNode(8); root->right->right = newNode(7); cout << "The Tilt of whole tree is " << Tilt(root); return 0; }
linear
linear
// C++ program to find averages of all levels // in a binary tree. #include <bits/stdc++.h> using namespace std; /* A binary tree node has data, pointer to left child and a pointer to right child */ struct Node { int data; struct Node* left, *right; }; string inorder(Node* node, unordered_map<string, int>& m) { if (!node) return ""; string str = "("; str += inorder(node->left, m); str += to_string(node->data); str += inorder(node->right, m); str += ")"; // Subtree already present (Note that we use // unordered_map instead of unordered_set // because we want to print multiple duplicates // only once, consider example of 4 in above // subtree, it should be printed only once. if (m[str] == 1) cout << node->data << " "; m[str]++; return str; } // Wrapper over inorder() void printAllDups(Node* root) { unordered_map<string, int> m; inorder(root, m); } /* Helper function that allocates a new node with the given data and NULL left and right pointers. */ Node* newNode(int data) { Node* temp = new Node; temp->data = data; temp->left = temp->right = NULL; return temp; } // Driver code int main() { Node* root = NULL; root = newNode(1); root->left = newNode(2); root->right = newNode(3); root->left->left = newNode(4); root->right->left = newNode(2); root->right->left->left = newNode(4); root->right->right = newNode(4); printAllDups(root); return 0; }
quadratic
quadratic
// CPP program to find largest three elements in // a binary tree. #include <bits/stdc++.h> using namespace std; struct Node { int data; struct Node *left; struct Node *right; }; /* Helper function that allocates a new Node with the given data and NULL left and right pointers. */ struct Node *newNode(int data) { struct Node *node = new Node; node->data = data; node->left = NULL; node->right = NULL; return (node); } // function to find three largest element void threelargest(Node *root, int &first, int &second, int &third) { if (root == NULL) return; // if data is greater than first large number // update the top three list if (root->data > first) { third = second; second = first; first = root->data; } // if data is greater than second large number // and not equal to first update the bottom // two list else if (root->data > second && root->data != first) { third = second; second = root->data; } // if data is greater than third large number // and not equal to first & second update the // third highest list else if (root->data > third && root->data != first && root->data != second) third = root->data; threelargest(root->left, first, second, third); threelargest(root->right, first, second, third); } // driver function int main() { struct Node *root = newNode(1); root->left = newNode(2); root->right = newNode(3); root->left->left = newNode(4); root->left->right = newNode(5); root->right->left = newNode(4); root->right->right = newNode(5); int first = 0, second = 0, third = 0; threelargest(root, first, second, third); cout << "three largest elements are " << first << " " << second << " " << third; return 0; }
constant
linear