You can choose from in-person surveys (one-on-one interviews carried out at high-traffic locations), telephone surveys (less expensive than one-to-one interviews), mail surveys (easy to reach a large audience) and online surveys (simple and inexpensive way to collect data, though not reliable).
A binary tree of depth d is an almost complete binary tree if: 1  Each leaf in the tree is either at level d or at level d â 1. 2  For any node nd in the tree with a right descendant at level d, all the left descendants of nd that are leaves are also at level d.
Introduction. An important special kind of binary tree is the binary search tree (BST). In a BST, each node stores some information including a unique key value and perhaps some associated data. A binary tree is a BST iff, for every node n, in the tree: 1  All keys in n 's left subtree are less than the key in n, and.he reason binary-search trees are important is that the following operations can be implemented efficiently using a BST: 1  insert a key value. 2  determine whether a key value is in the tree. 3  remove a key value from the tree.