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Course Schedule

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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] = [a, b] indicates that you must take course b before course a. Return true if you can finish all courses, or false otherwise.

Example:

Input: numCourses = 2, prerequisites = [[1,0]]
Output: true
Explanation: Take course 0 first, then course 1.

Example 2:

Input: numCourses = 2, prerequisites = [[1,0],[0,1]]
Output: false
Explanation: Courses 0 and 1 depend on each other — impossible.

Constraints:

  • 1 <= numCourses <= 2000
  • 0 <= prerequisites.length <= 5000
  • prerequisites[i].length == 2
  • 0 <= a, b < numCourses
  • All prerequisite pairs are unique