GeetCode Hub
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 bi first if you want to take course ai.
- For example, the pair
[0, 1], indicates that to take course0you have to first take course1.
You are also given an array queries where queries[j] = [uj, vj]. For the jth query, you should answer whether the course uj is a prerequisite of the course vj or not. Note that 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.
Return a boolean array answer, where answer[j] is the answer of the jth query.
Example 1:
Input: numCourses = 2, prerequisites = [[1,0]], queries = [[0,1],[1,0]] Output: [false,true] Explanation: 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 <= 1000 <= prerequisite.length <= (numCourses * (numCourses - 1) / 2)0 <= ai, bi < nai != bi- All the pairs
[ai, bi]are unique. - The prerequisites graph has no cycles.
1 <= queries.length <= 1040 <= ui, vi < nui != vi
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 bi first if you want to take course ai.
- For example, the pair
[0, 1], indicates that to take course0you have to first take course1.
You are also given an array queries where queries[j] = [uj, vj]. For the jth query, you should answer whether the course uj is a prerequisite of the course vj or not. Note that 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.
Return a boolean array answer, where answer[j] is the answer of the jth query.
Example 1:
Input: numCourses = 2, prerequisites = [[1,0]], queries = [[0,1],[1,0]] Output: [false,true] Explanation: 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 <= 1000 <= prerequisite.length <= (numCourses * (numCourses - 1) / 2)0 <= ai, bi < nai != bi- All the pairs
[ai, bi]are unique. - The prerequisites graph has no cycles.
1 <= queries.length <= 1040 <= ui, vi < nui != vi
class Solution {
public:
vector<bool> checkIfPrerequisite(int numCourses, vector<vector<int>>& prerequisites, vector<vector<int>>& queries) {
}
};