/in/foo.cc: In function 'int main()':
/in/foo.cc:42:29: warning: format '%d' expects argument of type 'int', but argument 2 has type 'std::vector<int>::size_type {aka long unsigned int}' [-Wformat=]
     printf("%d\n",ans.size());
                             ^
/in/foo.cc:43:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i=0;i<ans.size();i++)printf("%d\n",ans[i]);
                 ~^~~~~~~~~~~