/in/foo.cc: In function 'bool check(std::__cxx11::string)':
/in/foo.cc:5:26: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
  if(s.length()==1&&"0"<=s&&s<="9"||s.length()==2&&"10"<=s&&s<="99"||s.length()==2&&"100"<=s&&s<="199"||s.length()==2&&"200"<=s&&s<="255")return true;
     ~~~~~~~~~~~~~~~~~~~~~^~~~~~~~
/in/foo.cc:5:92: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
  if(s.length()==1&&"0"<=s&&s<="9"||s.length()==2&&"10"<=s&&s<="99"||s.length()==2&&"100"<=s&&s<="199"||s.length()==2&&"200"<=s&&s<="255")return true;
                                                                     ~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~
/in/foo.cc:5:127: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
  if(s.length()==1&&"0"<=s&&s<="9"||s.length()==2&&"10"<=s&&s<="99"||s.length()==2&&"100"<=s&&s<="199"||s.length()==2&&"200"<=s&&s<="255")return true;
                                                                                                        ~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~
/in/foo.cc: In function 'bool isLeagal(std::__cxx11::string)':
/in/foo.cc:10:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0;i<s.length();++i){
              ~^~~~~~~~~~~