foo.cc: In function 'int gy(int, int)':
foo.cc:20:6: warning: unused variable 'imin' [-Wunused-variable]
  int imin,imax;
      ^~~~
foo.cc:26:9: warning: 'imax' may be used uninitialized in this function [-Wmaybe-uninitialized]
  return imax;
         ^~~~
foo.cc: In function 'int main()':
foo.cc:20:11: warning: 'imax' may be used uninitialized in this function [-Wmaybe-uninitialized]
  int imin,imax;
           ^~~~

自豪的采用HydroJudge(https://github.com/hydro-dev/Hydro)进行评测。