/in/foo.cc: In function 'bool isCyclicNumber(const string&)':
/in/foo.cc:36:30: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   36 |         if (product.length() != n || !hasSameDigits(product, original)) {
      |             ~~~~~~~~~~~~~~~~~^~~~