foo.cc: In function ‘int main()’:
foo.cc:21:22: warning: comparison of integer expressions of different signedness: ‘int’ and ‘std::__cxx11::basic_string<char>::size_type’ {aka ‘long unsigned int’} [-Wsign-compare]
   21 |         for(int i=0;i<s.size();i++)
      |                     ~^~~~~~~~~
foo.cc:40:34: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses]
   40 |                         if(sum>=2&&TeShu==1||ok==1)
      |                            ~~~~~~^~~~~~~~~~