/in/foo.cc: In constructor 'BigInt::BigInt(std::string&)':
/in/foo.cc:12:30: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   12 |                 for(int i=0;i<str.length();i++)ints[i] = str[str.length() - i - 1] - '0';
      |                             ~^~~~~~~~~~~~~