foo.cc: In member function 'bool BigIntArray::operator>(BigIntArray&)':
foo.cc:21:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   21 |   for (int i = 0; i < a.size(); i++)
      |                   ~~^~~~~~~~~~
foo.cc: In function 'std::ostream& operator<<(std::ostream&, const BigIntArray&)':
foo.cc:27:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   27 |   for (int i = 0; i < A.a.size(); i++)
      |                   ~~^~~~~~~~~~~~
foo.cc: In member function 'bool BigIntArray::operator>(BigIntArray&)':
foo.cc:24:2: warning: control reaches end of non-void function [-Wreturn-type]
   24 |  }
      |  ^

[Hydro](https://hydro.ac)提供评测服务