/in/foo.cc: In member function 'bool Dinic::bfs()':
/in/foo.cc:37:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    for (int i=0;i<G[p].size();i++) {
                 ~^~~~~~~~~~~~
/in/foo.cc: In member function 'int Dinic::dfs(int, int)':
/in/foo.cc:52:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for (int &i=cur[x];i<G[x].size();i++) {
                      ~^~~~~~~~~~~~