Number of provinces

class Solution {
public:
    void dfs(vector<vector<int>> &graph, int node,vector<bool> &v){

        v[node] = true;

        for(int i = 0; i<graph[node].size(); i++){
            int newNode = graph[node][i];
            if(!v[newNode]){
                dfs(graph, newNode, v);
            }

        }

        return;

    }
    int findCircleNum(vector<vector<int>>& M) {
        int n = M.size();
        vector<vector<int>> graph(n);

        for(int i = 0; i<n; i++){
            for(int j=0; j<n; j++){
                if(M[i][j]==1){
                    graph[i].push_back(j);
                }
            }
        }

        int ans = 0;
        vector<bool> v(n,false);
        for(int i = 0; i<n; i++){
            if(!v[i]){
                dfs(graph, i, v);
                ans++;
            }
        }

        return ans;
    }
};