class Solution {
public:
    bool canVisitAllRooms(vector<vector<int>>& rooms) {

        int n = (int)rooms.size();
        if(!n) return 1;
        vector<int>visit(n,0);

      dfs(0, rooms, visit);

        bool ans = true;

        for( int i: visit)
        {
            ans&=i==1;
        }

        return ans;

    }

    private:
    void dfs(int node, vector<vector<int>>&rooms, vector<int>&visit)
    {
          visit[node] = 1;

        for( int neighbour : rooms[node])
        {
            if( !visit[neighbour] )
                dfs(neighbour, rooms, visit);
        }
    }
};