/in/foo.cc: In function 'int main()':
/in/foo.cc:19:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   19 |     for (int i = 0; i < s.size(); i++)
      |                     ~~^~~~~~~~~~
/in/foo.cc:42:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   42 |         for (int i = 0; i < v.size(); i++) cout << " " << v[i];
      |                         ~~^~~~~~~~~~