> For the complete documentation index, see [llms.txt](https://ondrej-kvasnovsky-2.gitbook.io/algorithms/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://ondrej-kvasnovsky-2.gitbook.io/algorithms/interviews/google-leetcode/course-schedule.md).

# Course Schedule

There are a total ofncourses 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: true
Explanation: 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: false
Explanation: 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:**

1. The input prerequisites is a graph represented by **a list of edges**, not adjacency matrices. Read more about [how a graph is represented](https://www.khanacademy.org/computing/computer-science/algorithms/graph-representation/a/representing-graphs).
2. You may assume that there are no duplicate edges in the input prerequisites.

## Solution

```
class Solution {
    public boolean canFinish(int numCourses, int[][] prerequisites) {

    }
}
```