/in/foo.cc: In member function 'int shupou::dfs2(int)':
/in/foo.cc:53:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i=0;i<T[x].ch.size();i++)
               ~^~~~~~~~~~~~~~~
/in/foo.cc: In member function 'void shupou::dfs3(int, int)':
/in/foo.cc:71:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i=0;i<T[x].ch.size();i++)
               ~^~~~~~~~~~~~~~~
/in/foo.cc: In member function 'void shupou::check()':
/in/foo.cc:91:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i=0;i<yezi.size();i++) cout<<yezi[i]<<" ";
               ~^~~~~~~~~~~~