/in/foo.cc: In function 'bool similar(std::string, std::string)':
/in/foo.cc:12:30: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   12 |                 for(int i=0;i<a.size();i++)
      |                             ~^~~~~~~~~
/in/foo.cc:18:34: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   18 |                 for(int i=0,j=0;i<a.size();i++)//不同则短串停
      |                                 ~^~~~~~~~~