/in/foo.cc: In function 'int main()':
/in/foo.cc:37:24: error: 'sort' was not declared in this scope
  sort(v.begin(),v.end());
                        ^
/in/foo.cc:39:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0;i<v.size();i++){
              ~^~~~~~~~~