foo.cc: In function ‘int main()’:
foo.cc:12:24: warning: comparison of integer expressions of different signedness: ‘int’ and ‘std::__cxx11::basic_string<char>::size_type’ {aka ‘long unsigned int’} [-Wsign-compare]
   12 |                 while(j<=s.size())
      |                       ~^~~~~~~~~~
foo.cc:14:34: warning: comparison of integer expressions of different signedness: ‘int’ and ‘std::__cxx11::basic_string<char>::size_type’ {aka ‘long unsigned int’} [-Wsign-compare]
   14 |                         for(j=0;j<=s.size();j++)
      |                                 ~^~~~~~~~~~