/in/foo.cc: In function 'int DFS(int)':
/in/foo.cc:31:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<edgenode>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   31 |     for (int z = 0; z < edge[x].size(); z++)
      |                     ~~^~~~~~~~~~~~~~~~
/in/foo.cc:38:1: warning: no return statement in function returning non-void [-Wreturn-type]
   38 | }
      | ^
/in/foo.cc:27:5: warning: infinite recursion detected [-Winfinite-recursion]
   27 | int DFS(int x)
      |     ^~~
/in/foo.cc:34:25: note: recursive call
   34 |         if (b[y.to]) DFS(y.to);
      |                      ~~~^~~~~~