foo.cc: In function ‘bool check(std::string)’:
foo.cc:7:22: warning: comparison of integer expressions of different signedness: ‘int’ and ‘std::__cxx11::basic_string<char>::size_type’ {aka ‘long unsigned int’} [-Wsign-compare]
    7 |         for(int i=0;i<s.size();i++){
      |                     ~^~~~~~~~~
foo.cc:6:14: warning: unused variable ‘hasA’ [-Wunused-variable]
    6 |         bool hasA=0,hasa=0,has0=0,hasTeShu=0,length_is_ok=0;
      |              ^~~~
foo.cc:6:21: warning: unused variable ‘hasa’ [-Wunused-variable]
    6 |         bool hasA=0,hasa=0,has0=0,hasTeShu=0,length_is_ok=0;
      |                     ^~~~
foo.cc:6:28: warning: unused variable ‘has0’ [-Wunused-variable]
    6 |         bool hasA=0,hasa=0,has0=0,hasTeShu=0,length_is_ok=0;
      |                            ^~~~
foo.cc:6:35: warning: unused variable ‘hasTeShu’ [-Wunused-variable]
    6 |         bool hasA=0,hasa=0,has0=0,hasTeShu=0,length_is_ok=0;
      |                                   ^~~~~~~~
foo.cc:6:46: warning: unused variable ‘length_is_ok’ [-Wunused-variable]
    6 |         bool hasA=0,hasa=0,has0=0,hasTeShu=0,length_is_ok=0;
      |                                              ^~~~~~~~~~~~
foo.cc: In function ‘int main()’:
foo.cc:29:22: warning: comparison of integer expressions of different signedness: ‘int’ and ‘std::__cxx11::basic_string<char>::size_type’ {aka ‘long unsigned int’} [-Wsign-compare]
   29 |         for(int i=0;i<s.size();i++){
      |                     ~^~~~~~~~~