/in/foo.cc: In function 'void DelNum(std::vector<int>&)':
/in/foo.cc:9:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
    9 |         for (int i=0;i<v.size();)
      |                      ~^~~~~~~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:26:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   26 |         for (int i=0;i<s.size();i++)
      |                      ~^~~~~~~~~
/in/foo.cc:32:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   32 |         for (int i=0;i<v.size();i++)
      |                      ~^~~~~~~~~