/in/foo.cc: In function 'void zhengxiangsousuo(int)':
/in/foo.cc:19:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0;i<G[v].size();i++)
              ~^~~~~~~~~~~~
/in/foo.cc: In function 'void fanxiangsousuo(int, int)':
/in/foo.cc:30:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0;i<rG[a].size();i++)
              ~^~~~~~~~~~~~~
/in/foo.cc: In function 'void dongtaiguihua(int)':
/in/foo.cc:48:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0;i<G2[v].size();i++)
              ~^~~~~~~~~~~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:91:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int j=0;j<G[i].size();j++)
               ~^~~~~~~~~~~~