/in/foo.cc: In function 'bool isPalindrome(long long int)':
/in/foo.cc:3:67: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
    3 | bool isPalindrome(long long n){string s=to_string(n);for(int i=0;i<s.size()/2;i++)if(s[i]!=s[s.size()-1-i])return false;return true;}
      |                                                                  ~^~~~~~~~~~~