/in/foo.cc: In function 'int main()':
/in/foo.cc:18:36: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
  if(ans%11==(s[12]-'0')||s[12]=='X'&&ans%11==10){
                                     
/in/foo.cc:23:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i=0;i<s.size()-1;i++) cout<<s[i];
               ~^~~~~~~~~~~
/in/foo.cc:8:17: warning: unused variable 'j' [-Wunused-variable]
  register int i,j; //寄存器变量加速
                 ^