foo.cc: In function 'int main()':
foo.cc:15:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   15 |         for (int i = 0; i < b.size(); i++) {
      |                         ~~^~~~~~~~~~
foo.cc:39:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   39 |                 if (p >= a.size()) {
      |                     ~~^~~~~~~~~~~

[Hydro](https://hydro.ac)提供评测服务