18 May | 1557. Minimum Number of Vertices to Reach All Nodes.cpp

class Solution {
public:
    vector<int> findSmallestSetOfVertices(int n, vector<vector<int>>& edges) {
        vector<int> ans;
        vector<int> indegree(n,0);
        for(auto it:edges){
            indegree[it[1]]+=1;
        }
        for(int i = 0; i < n; i++){
            if(indegree[i] == 0){
                ans.push_back(i);
            }
        }
        return ans;
    }
};