/in/foo.cc: In function 'void dfs(int)':
/in/foo.cc:14:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0;i<child[u].size();i++) dfs(child[u][i]);
                 ~^~~~~~~~~~~~~~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:44:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(int j=0;j<party[i].size();j++)
                     ~^~~~~~~~~~~~~~~~
/in/foo.cc:49:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(int j=0;j<party[i].size();j++)
                     ~^~~~~~~~~~~~~~~~