/in/foo.cc: In function 'bool DFS(int, int)':
/in/foo.cc:11:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int k=0;k<g[i].size();k++){
              ~^~~~~~~~~~~~
/in/foo.cc: In function 'bool BFS(int)':
/in/foo.cc:26:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int k=0;k<g[i].size();k++){
               ~^~~~~~~~~~~~
/in/foo.cc:25:7: warning: unused variable 'j' [-Wunused-variable]
   int j=q.front(); q.pop();
       ^