LeetCode #207 - Course Schedule

There are a total of n courses you have to take, labeled from 0 to n - 1. Some courses may have prerequisites, forming a directed graph where each edge (a, b) indicates that you must take course a before course b. Determine if you can finish all courses.

Example 1:

Input: numCourses = 2, prerequisites = [[1,0]]
Output: true
Explanation: There are a total of 2 courses to take. To take course 1 you should have finished course 0. So it is possible.

Example 2:

Input: numCourses = 2, prerequisites = [[1,0],[0,1]]
Output: false
Explanation: There are a total of 2 courses. But there are prerequisites that create a cycle.

Constraints:

* 1 <= numCourses <= 2000
* 0 <= prerequisites.length <= 5000
* prerequisites[i].length == 2