239. Course Schedule — Cycle Detection in Directed Graph

Medium · Graph

There are `numCourses` courses labelled 0 to n-1. Given an array `prerequisites` where [a, b] means you must take course b before a, determine if it is possible to finish all courses.

Examples

Example 1
Input: numCourses=2, prerequisites=[[1,0]]
Output: true
Explanation: Take course 0 then course 1
Example 2
Input: numCourses=2, prerequisites=[[1,0],[0,1]]
Output: false
Explanation: Circular dependency

Constraints