/in/foo.cc: In function 'bool check(std::__cxx11::string, std::__cxx11::string)':
/in/foo.cc:15:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=1;i<a.size();i++)//逐个比对
              ~^~~~~~~~~
/in/foo.cc:18:6: error: 'temp' was not declared in this scope
   if(temp>7)  temp-=26;
      ^~~~
/in/foo.cc:19:6: error: 'temp' was not declared in this scope
   if(temp<=-23)   temp+=26;
      ^~~~
/in/foo.cc:20:6: error: 'temp' was not declared in this scope
   if(temp!=k) return false;
      ^~~~