/in/foo.cc: In member function 'int Dinic::dfs(int, int, int)':
/in/foo.cc:59:37: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<Edge>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   59 |         for (int &cid = ptr[v]; cid < adj[v].size(); ++cid)
      |                                 ~~~~^~~~~~~~~~~~~~~