/in/foo.cc: In function 'void setl(std::vector<int>&, std::vector<int>&)':
/in/foo.cc:19:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   19 |     for (int i = 0; i < v1.size(); i++)
      |                     ~~^~~~~~~~~~~
/in/foo.cc:26:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   26 |     for (int i = 0; i < ret.size(); i++)
      |                     ~~^~~~~~~~~~~~
/in/foo.cc:39:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   39 |     for (int i = 0; i < ret.size();i++)
      |                     ~~^~~~~~~~~~~~