/in/foo.cc: In function 'std::string decimalToBinary(int)':
/in/foo.cc:4:9: error: 's' was not declared in this scope
    4 |         s="";
      |         ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:17:38: 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(int j=0;j<c.length();j++){
      |                                     ~^~~~~~~~~~~