push_back edges
g [ 1 ] . push_back ( 2 ) ; g [ 2 ] . push_back ( 1 ) ; g [ 1 ] . push_back ( 3 ) ; g [ 3 ] . push_back ( 1 ) ; g [ 1 ] . push_back ( 4 ) ; g [ 4 ] . push_back ( 1 ) ; dfs ( 1 , 0 ) ; cout << ( ans ) ; }