// Course Schedule — MEDIUM

// Category: graph

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`.

Return `true` if you can finish all courses, otherwise `false`.

**Hint:** This is a cycle detection problem in a directed graph. Use DFS or BFS (Kahn's algorithm).

Example: numCourses = 2, prerequisites = [[1,0]]

Output: true