foo.cc: In function 'int main()':
foo.cc:13:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   13 |         for(int i = 0; i < s.size() - 2; i++){
      |                        ~~^~~~~~~~~~~~~~
foo.cc:33:42: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   33 |                         for(int i = 0; i < s.size() - 1; i++){
      |                                        ~~^~~~~~~~~~~~~~
foo.cc:46:42: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   46 |                         for(int i = 0; i < s.size() - 1; i++){
      |                                        ~~^~~~~~~~~~~~~~

正在同步测试数据，请稍后
[Hydro](https://hydro.ac)提供评测服务