/in/foo.cc: In function 'bool judge(std::vector<int>)':
/in/foo.cc:9:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0; i<cnt.size(); i++){
               ~^~~~~~~~~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:34:26: warning: format '%d' expects argument of type 'int', but argument 2 has type 'std::vector<std::vector<int> >::size_type {aka long unsigned int}' [-Wformat=]
  printf("%d\n",ans.size());
                          ^
/in/foo.cc:35:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0; i<ans.size(); i++){
               ~^~~~~~~~~~~