/in/foo.cc: In member function 'bool Dinic::BFS()':
/in/foo.cc:54:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             for(int i = 0; i < G[x].size(); i++) {
                            ~~^~~~~~~~~~~~~
/in/foo.cc: In member function 'int Dinic::DFS(int, int)':
/in/foo.cc:69:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(int &i = cur[x]; i < G[x].size(); i++) {
                              ~~^~~~~~~~~~~~~