Course Schedule IV
<p>There are a total of <code>numCourses</code> courses you have to take, labeled from <code>0</code> to <code>numCourses - 1</code>. You are given an array <code>prerequisites</code> where <code>prerequisites[i] = [a<sub>i</sub>, b<sub>i</sub>]</code> indicates that you <strong>must</strong> take course <code>a<sub>i</sub></code> first if you want to take course <code>b<sub>i</sub></code>.</p>

<ul>
	<li>For example, the pair <code>[0, 1]</code> indicates that you have to take course <code>0</code> before you can take course <code>1</code>.</li>
</ul>

<p>Prerequisites can also be <strong>indirect</strong>. If course <code>a</code> is a prerequisite of course <code>b</code>, and course <code>b</code> is a prerequisite of course <code>c</code>, then course <code>a</code> is a prerequisite of course <code>c</code>.</p>

<p>You are also given an array <code>queries</code> where <code>queries[j] = [u<sub>j</sub>, v<sub>j</sub>]</code>. For the <code>j<sup>th</sup></code> query, you should answer whether course <code>u<sub>j</sub></code> is a prerequisite of course <code>v<sub>j</sub></code> or not.</p>

<p>Return <i>a boolean array </i><code>answer</code><i>, where </i><code>answer[j]</code><i> is the answer to the </i><code>j<sup>th</sup></code><i> query.</i></p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2021/05/01/courses4-1-graph.jpg" style="width: 222px; height: 62px;" />
<pre>
<strong>Input:</strong> numCourses = 2, prerequisites = [[1,0]], queries = [[0,1],[1,0]]
<strong>Output:</strong> [false,true]
<strong>Explanation:</strong> The pair [1, 0] indicates that you have to take course 1 before you can take course 0.
Course 0 is not a prerequisite of course 1, but the opposite is true.
</pre>

<p><strong class="example">Example 2:</strong></p>

<pre>
<strong>Input:</strong> numCourses = 2, prerequisites = [], queries = [[1,0],[0,1]]
<strong>Output:</strong> [false,false]
<strong>Explanation:</strong> There are no prerequisites, and each course is independent.
</pre>

<p><strong class="example">Example 3:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2021/05/01/courses4-3-graph.jpg" style="width: 222px; height: 222px;" />
<pre>
<strong>Input:</strong> numCourses = 3, prerequisites = [[1,2],[1,0],[2,0]], queries = [[1,0],[1,2]]
<strong>Output:</strong> [true,true]
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>2 &lt;= numCourses &lt;= 100</code></li>
	<li><code>0 &lt;= prerequisites.length &lt;= (numCourses * (numCourses - 1) / 2)</code></li>
	<li><code>prerequisites[i].length == 2</code></li>
	<li><code>0 &lt;= a<sub>i</sub>, b<sub>i</sub> &lt;= numCourses - 1</code></li>
	<li><code>a<sub>i</sub> != b<sub>i</sub></code></li>
	<li>All the pairs <code>[a<sub>i</sub>, b<sub>i</sub>]</code> are <strong>unique</strong>.</li>
	<li>The prerequisites graph has no cycles.</li>
	<li><code>1 &lt;= queries.length &lt;= 10<sup>4</sup></code></li>
	<li><code>0 &lt;= u<sub>i</sub>, v<sub>i</sub> &lt;= numCourses - 1</code></li>
	<li><code>u<sub>i</sub> != v<sub>i</sub></code></li>
</ul>

[]
[]
[{"value": "cpp", "text": "C++", "defaultCode": "class Solution {\npublic:\n    vector<bool> checkIfPrerequisite(int numCourses, vector<vector<int>>& prerequisites, vector<vector<int>>& queries) {\n        \n    }\n};"}, {"value": "java", "text": "Java", "defaultCode": "class Solution {\n    public List<Boolean> checkIfPrerequisite(int numCourses, int[][] prerequisites, int[][] queries) {\n        \n    }\n}"}, {"value": "python", "text": "Python", "defaultCode": "class Solution(object):\n    def checkIfPrerequisite(self, numCourses, prerequisites, queries):\n        \"\"\"\n        :type numCourses: int\n        :type prerequisites: List[List[int]]\n        :type queries: List[List[int]]\n        :rtype: List[bool]\n        \"\"\"\n        "}, {"value": "python3", "text": "Python3", "defaultCode": "class Solution:\n    def checkIfPrerequisite(self, numCourses: int, prerequisites: List[List[int]], queries: List[List[int]]) -> List[bool]:\n        "}, {"value": "c", "text": "C", "defaultCode": "/**\n * Note: The returned array must be malloced, assume caller calls free().\n */\nbool* checkIfPrerequisite(int numCourses, int** prerequisites, int prerequisitesSize, int* prerequisitesColSize, int** queries, int queriesSize, int* queriesColSize, int* returnSize) {\n    \n}"}, {"value": "csharp", "text": "C#", "defaultCode": "public class Solution {\n    public IList<bool> CheckIfPrerequisite(int numCourses, int[][] prerequisites, int[][] queries) {\n        \n    }\n}"}, {"value": "javascript", "text": "JavaScript", "defaultCode": "/**\n * @param {number} numCourses\n * @param {number[][]} prerequisites\n * @param {number[][]} queries\n * @return {boolean[]}\n */\nvar checkIfPrerequisite = function(numCourses, prerequisites, queries) {\n    \n};"}, {"value": "typescript", "text": "TypeScript", "defaultCode": "function checkIfPrerequisite(numCourses: number, prerequisites: number[][], queries: number[][]): boolean[] {\n    \n};"}, {"value": "php", "text": "PHP", "defaultCode": "class Solution {\n\n    /**\n     * @param Integer $numCourses\n     * @param Integer[][] $prerequisites\n     * @param Integer[][] $queries\n     * @return Boolean[]\n     */\n    function checkIfPrerequisite($numCourses, $prerequisites, $queries) {\n        \n    }\n}"}, {"value": "swift", "text": "Swift", "defaultCode": "class Solution {\n    func checkIfPrerequisite(_ numCourses: Int, _ prerequisites: [[Int]], _ queries: [[Int]]) -> [Bool] {\n        \n    }\n}"}, {"value": "kotlin", "text": "Kotlin", "defaultCode": "class Solution {\n    fun checkIfPrerequisite(numCourses: Int, prerequisites: Array<IntArray>, queries: Array<IntArray>): List<Boolean> {\n        \n    }\n}"}, {"value": "dart", "text": "Dart", "defaultCode": "class Solution {\n  List<bool> checkIfPrerequisite(int numCourses, List<List<int>> prerequisites, List<List<int>> queries) {\n    \n  }\n}"}, {"value": "golang", "text": "Go", "defaultCode": "func checkIfPrerequisite(numCourses int, prerequisites [][]int, queries [][]int) []bool {\n    \n}"}, {"value": "ruby", "text": "Ruby", "defaultCode": "# @param {Integer} num_courses\n# @param {Integer[][]} prerequisites\n# @param {Integer[][]} queries\n# @return {Boolean[]}\ndef check_if_prerequisite(num_courses, prerequisites, queries)\n    \nend"}, {"value": "scala", "text": "Scala", "defaultCode": "object Solution {\n    def checkIfPrerequisite(numCourses: Int, prerequisites: Array[Array[Int]], queries: Array[Array[Int]]): List[Boolean] = {\n        \n    }\n}"}, {"value": "rust", "text": "Rust", "defaultCode": "impl Solution {\n    pub fn check_if_prerequisite(num_courses: i32, prerequisites: Vec<Vec<i32>>, queries: Vec<Vec<i32>>) -> Vec<bool> {\n        \n    }\n}"}, {"value": "racket", "text": "Racket", "defaultCode": "(define/contract (check-if-prerequisite numCourses prerequisites queries)\n  (-> exact-integer? (listof (listof exact-integer?)) (listof (listof exact-integer?)) (listof boolean?))\n  )"}, {"value": "erlang", "text": "Erlang", "defaultCode": "-spec check_if_prerequisite(NumCourses :: integer(), Prerequisites :: [[integer()]], Queries :: [[integer()]]) -> [boolean()].\ncheck_if_prerequisite(NumCourses, Prerequisites, Queries) ->\n  ."}, {"value": "elixir", "text": "Elixir", "defaultCode": "defmodule Solution do\n  @spec check_if_prerequisite(num_courses :: integer, prerequisites :: [[integer]], queries :: [[integer]]) :: [boolean]\n  def check_if_prerequisite(num_courses, prerequisites, queries) do\n    \n  end\nend"}]
{
  "name": "checkIfPrerequisite",
  "params": [
    {
      "name": "numCourses",
      "type": "integer"
    },
    {
      "type": "integer[][]",
      "name": "prerequisites"
    },
    {
      "type": "integer[][]",
      "name": "queries"
    }
  ],
  "return": {
    "type": "list<boolean>"
  }
}
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Using compile arguments: <code>--enable-preview --release 21</code></p>\r\n\r\n<p>Most standard library headers are already included automatically for your convenience.</p>\r\n<p>Includes <code>Pair</code> class from https://docs.oracle.com/javase/8/javafx/api/javafx/util/Pair.html.</p>"], "python": ["Python", "<p><code>Python 2.7.18</code>.</p>\r\n\r\n<p>Most libraries are already imported automatically for your convenience, such as <a href=\"https://docs.python.org/2/library/array.html\" target=\"_blank\">array</a>, <a href=\"https://docs.python.org/2/library/bisect.html\" target=\"_blank\">bisect</a>, <a href=\"https://docs.python.org/2/library/collections.html\" target=\"_blank\">collections</a>. If you need more libraries, you can import it yourself.</p>\r\n\r\n<p>For Map/TreeMap data structure, you may use <a href=\"http://www.grantjenks.com/docs/sortedcontainers/\" target=\"_blank\">sortedcontainers</a> library.</p>\r\n\r\n<p>Note that Python 2.7 <a href=\"https://www.python.org/dev/peps/pep-0373/\" target=\"_blank\">is not maintained anymore</a>. For the latest Python, please choose Python3 instead.</p>"], "c": ["C", "<p>Compiled with <code>gcc 14</code> using the gnu11 standard.</p>\r\n\r\n<p>Your code is compiled with level one optimization (<code>-O2</code>). <a href=\"https://github.com/google/sanitizers/wiki/AddressSanitizer\" target=\"_blank\">AddressSanitizer</a> is also enabled to help detect out-of-bounds and use-after-free bugs.</p>\r\n\r\n<p>Most standard library headers are already included automatically for your convenience.</p>\r\n\r\n<p>For hash table operations, you may use <a href=\"https://troydhanson.github.io/uthash/\" target=\"_blank\">uthash</a>. \"uthash.h\" is included by default. Below are some examples:</p>\r\n\r\n<p><b>1. Adding an item to a hash.</b>\r\n<pre>\r\nstruct hash_entry {\r\n    int id;            /* we'll use this field as the key */\r\n    char name[10];\r\n    UT_hash_handle hh; /* makes this structure hashable */\r\n};\r\n\r\nstruct hash_entry *users = NULL;\r\n\r\nvoid add_user(struct hash_entry *s) {\r\n    HASH_ADD_INT(users, id, s);\r\n}\r\n</pre>\r\n</p>\r\n\r\n<p><b>2. Looking up an item in a hash:</b>\r\n<pre>\r\nstruct hash_entry *find_user(int user_id) {\r\n    struct hash_entry *s;\r\n    HASH_FIND_INT(users, &user_id, s);\r\n    return s;\r\n}\r\n</pre>\r\n</p>\r\n\r\n<p><b>3. Deleting an item in a hash:</b>\r\n<pre>\r\nvoid delete_user(struct hash_entry *user) {\r\n    HASH_DEL(users, user);  \r\n}\r\n</pre>\r\n</p>"], "csharp": ["C#", "<p><a href=\"https://learn.microsoft.com/en-us/dotnet/csharp/whats-new/csharp-13\" target=\"_blank\">C# 13</a> with .NET 9 runtime</p>"], "javascript": ["JavaScript", "<p><code>Node.js 22.14.0</code>.</p>\r\n\r\n<p>Your code is run with <code>--harmony</code> flag, enabling <a href=\"http://node.green/\" target=\"_blank\">new ES6 features</a>.</p>\r\n\r\n<p><a href=\"https://lodash.com\" target=\"_blank\">lodash.js</a> library is included by default.</p>\r\n\r\n<p>For Priority Queue / Queue data structures, you may use 6.3.2 version of <a href=\"https://github.com/datastructures-js/priority-queue/tree/v6.3.2\" target=\"_blank\">datastructures-js/priority-queue</a> and 4.2.3 version of <a href=\"https://github.com/datastructures-js/queue/tree/v4.2.3\" target=\"_blank\">datastructures-js/queue</a> and 1.0.4 version of <a href=\"https://github.com/datastructures-js/deque/tree/v1.0.4\" target=\"_blank\">datastructures-js/deque</a>.</p>"], "ruby": ["Ruby", "<p><code>Ruby 3.2</code></p>\r\n\r\n<p>Some common data structure implementations are provided in the Algorithms module: https://www.rubydoc.info/github/kanwei/algorithms/Algorithms</p>"], "swift": ["Swift", "<p><code>Swift 6.0</code>.</p>\r\n\r\n<p>You may use the following packages:<br/>\r\n<a href=\"https://github.com/apple/swift-algorithms/tree/1.2.0\" target=\"_blank\">swift-algorithms 1.2.0</a><br/>\r\n<a href=\"https://github.com/apple/swift-collections/tree/1.1.4\" target=\"_blank\">swift-collections 1.1.4</a><br/>\r\n<a href=\"https://github.com/apple/swift-numerics/tree/1.0.2\" target=\"_blank\">swift-numerics 1.0.2</a></p>"], "golang": ["Go", "<p><code>Go 1.23</code></p>\r\n<p>Support <a href=\"https://pkg.go.dev/github.com/emirpasic/gods@v1.18.1\" target=\"_blank\">https://pkg.go.dev/github.com/emirpasic/gods@v1.18.1</a> and <a href=\"https://pkg.go.dev/github.com/emirpasic/gods/v2@v2.0.0-alpha\" target=\"_blank\">https://pkg.go.dev/github.com/emirpasic/gods/v2@v2.0.0-alpha</a> library.</p>"], "python3": ["Python3", "<p><code>Python 3.11</code>.</p>\r\n\r\n<p>Most libraries are already imported automatically for your convenience, such as <a href=\"https://docs.python.org/3/library/array.html\" target=\"_blank\">array</a>, <a href=\"https://docs.python.org/3/library/bisect.html\" target=\"_blank\">bisect</a>, <a href=\"https://docs.python.org/3/library/collections.html\" target=\"_blank\">collections</a>. If you need more libraries, you can import it yourself.</p>\r\n\r\n<p>For Map/TreeMap data structure, you may use <a href=\"http://www.grantjenks.com/docs/sortedcontainers/\" target=\"_blank\">sortedcontainers</a> library.</p>"], "scala": ["Scala", "<p><code>Scala 3.3.1</code>.</p>"], "kotlin": ["Kotlin", "<p><code>Kotlin 2.1.10</code>.</p>"], "rust": ["Rust", "<p><code>Rust 1.85.0</code>. Your code will be compiled with <code>opt-level</code> 2.</p>\r\n\r\n<p>Supports <a href=\"https://crates.io/crates/rand\" target=\"_blank\">rand v0.8</a> and <a href=\"https://crates.io/crates/regex\" target=\"_blank\">regex\u00a0v1</a> and <a href=\"https://crates.io/crates/itertools\" target=\"_blank\">itertools\u00a0v0.14</a> from crates.io</p>"], "php": ["PHP", "<p><code>PHP 8.2</code>.</p>\r\n<p>With bcmath module</p>"], "typescript": ["Typescript", "<p><code>TypeScript 5.7.3, Node.js 22.14.0</code>.</p>\r\n\r\n<p>Compile Options: <code>--alwaysStrict --strictBindCallApply --strictFunctionTypes --target ES2024</code></p>\r\n\r\n<p><a href=\"https://lodash.com\" target=\"_blank\">lodash.js</a> library is included by default.</p>\r\n\r\n<p>For Priority Queue / Queue data structures, you may use 6.3.2 version of <a href=\"https://github.com/datastructures-js/priority-queue/tree/v6.3.2\" target=\"_blank\">datastructures-js/priority-queue</a> and 4.2.3 version of <a href=\"https://github.com/datastructures-js/queue/tree/v4.2.3\" target=\"_blank\">datastructures-js/queue</a> and 1.0.4 version of <a href=\"https://github.com/datastructures-js/deque/tree/v1.0.4\" target=\"_blank\">datastructures-js/deque</a>.</p>"], "racket": ["Racket", "<p><a href=\"https://docs.racket-lang.org/guide/performance.html#%28tech._c%29\" target=\"_blank\">Racket CS</a> v8.15</p>\r\n\r\n<p>Using <code>#lang racket</code></p>\r\n\r\n<p>Required <code>data/gvector data/queue data/order data/heap</code> automatically for your convenience</p>"], "erlang": ["Erlang", "Erlang/OTP 26"], "elixir": ["Elixir", "Elixir 1.17 with Erlang/OTP 26"], "dart": ["Dart", "<p>Dart 3.2. You may use package <a href=\"https://pub.dev/packages/collection/versions/1.18.0\" target=\"_blank\">collection</a></p>\r\n\r\n<p>Your code will be run directly without compiling</p>"]}
['Depth-First Search', 'Breadth-First Search', 'Graph', 'Topological Sort']