/in/foo.cc: In function 'int Atoi(std::__cxx11::string, int)':
/in/foo.cc:19:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i < s.size(); i++)
                  ~~^~~~~~~~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:38:13: warning: unused variable 'k' [-Wunused-variable]
  int jinzhi,k=0,count=0;
             ^