本网站所有文字及图片内容均来自网络，每周定时更新，仅供个人学习与研究，请勿用于商业用途。谢谢合作。

There are a total of *n* courses you have to take, labeled from `0`

to `n-1`

.

Some courses may have prerequisites, for example to take course 0 you have to first take course 1, which is expressed as a pair: `[0,1]`

Given the total number of courses and a list of prerequisite **pairs**, is it possible for you to finish all courses?

**Example 1:**

Input:2, [[1,0]]Output:trueExplanation: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:2, [[1,0],[0,1]]Output:falseExplanation:There are a total of 2 courses to take. To take course 1 you should have finished course 0, and to take course 0 you should also have finished course 1. So it is impossible.

**Note:**

- The input prerequisites is a graph represented by
**a list of edges**, not adjacency matrices. Read more about how a graph is represented. - You may assume that there are no duplicate edges in the input prerequisites.