/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:19:19: warning: 'temp' may be used uninitialized in this function [-Wmaybe-uninitialized]
   if(temp>7)  temp-=26;
               ~~~~^~~~