1462. Course Schedule IV

https://leetcode.com/problems/course-schedule-iv

Description

There are a total of numCourses courses you have to take, labeled from 0 to numCourses - 1. You are given an array prerequisites where prerequisites[i] = [ai, bi] indicates that you must take course ai first if you want to take course bi.

• For example, the pair [0, 1] indicates that you have to take course 0 before you can take course 1.

Prerequisites can also be indirect. If course a is a prerequisite of course b, and course b is a prerequisite of course c, then course a is a prerequisite of course c.

You are also given an array queries where queries[j] = [uj, vj]. For the jth query, you should answer whether course uj is a prerequisite of course vj or not.

Return a boolean array answer, where answer[j] is the answer to the jth query.

Example 1:

**Input:** numCourses = 2, prerequisites = [[1,0]], queries = [[0,1],[1,0]]
**Output:** [false,true]
**Explanation:** 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.

Example 2:

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

Example 3:

**Input:** numCourses = 3, prerequisites = [[1,2],[1,0],[2,0]], queries = [[1,0],[1,2]]
**Output:** [true,true]

Constraints:

• 2 <= numCourses <= 100

• 0 <= prerequisites.length <= (numCourses * (numCourses - 1) / 2)

• prerequisites[i].length == 2

• 0 <= ai, bi <= n - 1

• ai != bi

• All the pairs [ai, bi] are unique.

• The prerequisites graph has no cycles.

• 1 <= queries.length <= 104

• 0 <= ui, vi <= n - 1

• ui != vi

ac