/in/foo.cc: In function 'int count0(std::__cxx11::string)':
/in/foo.cc:20:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0;i<num.size();i++)
              ~^~~~~~~~~~~
/in/foo.cc: In function 'int count1(std::__cxx11::string)':
/in/foo.cc:28:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0;i<num.size();i++)
              ~^~~~~~~~~~~