void DFS_visit(int u){
   visited[u] = true; //marks node u as visited
   for(int v = 1; v <= n; v = v+1){ //checks all nodes
       if(visited[v] == false && Adj[u][v] == true) //checks if node v is connected to u and hasn’t been visited yet
           DFS_visit(v); //if yes, calls DFS_visit() for node v
   }
}