/in/foo.cc: In function 'bool pd(std::string)':
/in/foo.cc:15:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   15 |         for(int i=0;i<s.size();i++){
      |                     ~^~~~~~~~~
/in/foo.cc:18:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   18 |                 if(i<s.size()-1&&s[i+1]==s[i])ok=1;
      |                    ~^~~~~~~~~~~