foo.cc: In function ‘int main()’:
foo.cc:39:29: warning: comparison of integer expressions of different signedness: ‘std::vector<int>::size_type’ {aka ‘long unsigned int’} and ‘int’ [-Wsign-compare]
   39 |                 if (v.size()==n) break;
      |                     ~~~~~~~~^~~
foo.cc:54:23: warning: comparison of integer expressions of different signedness: ‘int’ and ‘std::vector<int>::size_type’ {aka ‘long unsigned int’} [-Wsign-compare]
   54 |         for (int i=0;i<v.size();i++) cout<<v[i]<<" ";
      |                      ~^~~~~~~~~