TopoSort-Snippet3.java

import java.util.ArrayList;
import java.util.List;
class Solution {
    public boolean canFinish(int numTasks, int[][] prerequisites) {
         ...
        for (int i = 0; i < numTasks; i++) {
            if (adjacencyList[i] != null) {
                return false;
            }
        }
        return true;

    }

}