/in/foo.cc: In function 'int main()':
/in/foo.cc:123:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  123 |             for (int j=0;j<a_s[i].size();j++)
      |                          ~^~~~~~~~~~~~~~
/in/foo.cc:138:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  138 |             for (int j=0;j<b_s[i].size();j++)
      |                          ~^~~~~~~~~~~~~~
/in/foo.cc:155:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  155 |             for (int i=0;i<p_1_s.size();i++)
      |                          ~^~~~~~~~~~~~~
/in/foo.cc:161:31: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  161 |                 for (int i=0;i<p_2_s.size();i++)
      |                              ~^~~~~~~~~~~~~