/in/foo.cc: In member function 'BigInt BigInt::operator*(const BigInt&) const':
/in/foo.cc:42:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   42 |         for (int i = 0; i < digits.size(); i++) {
      |                         ~~^~~~~~~~~~~~~~~
/in/foo.cc:43:31: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   43 |             for (int j = 0; j < other.digits.size(); j++) {
      |                             ~~^~~~~~~~~~~~~~~~~~~~~