Question

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?

For example:

1

2, [[1,0]]

There are a total of 2 courses to take. To take course 1 you should have finished course 0. So it is possible.

1

2, [[1,0],[0,1]]

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.

在我看来，整本书都在讲一个寓意深刻的寓言。

Time flies by, but we can capture it.

TimeCapturor

每次出去玩，我都喜欢拍街上的孩子。

回来看照片的时候，总感觉他们的脸上或者眼睛里充满了让人无限想象的故事。