/in/foo.cc: In function 'void f(std::__cxx11::string, std::__cxx11::string)':
/in/foo.cc:11:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i=0;i<hou.size();i++)
               ~^~~~~~~~~~~
/in/foo.cc:13:10: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    if(i+1==hou.size())
       ~~~^~~~~~~~~~~~
/in/foo.cc:19:19: warning: 'a' may be used uninitialized in this function [-Wmaybe-uninitialized]
   int b=zhong.find(a);
         ~~~~~~~~~~^~~