/in/foo.cc: In function 'int main()':
/in/foo.cc:17:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   17 |   for (i = 0; i < s.length() && flag; i++)
      |               ~~^~~~~~~~~~~~
/in/foo.cc:19:18: 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 (j = 0; j < s.length(); j++)
      |                ~~^~~~~~~~~~~~
/in/foo.cc:22:10: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   22 |    if (j == s.length())
      |        ~~^~~~~~~~~~~~~
/in/foo.cc:32:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   32 |   for (i = 0; i < s.length() && flag; i++)
      |               ~~^~~~~~~~~~~~
/in/foo.cc:34:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   34 |    for (j = 0; j < s.length(); j++)
      |                ~~^~~~~~~~~~~~
/in/foo.cc:37:10: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   37 |    if (j == s.length())
      |        ~~^~~~~~~~~~~~~