foo.cc: In function 'int gys(int, int)':
foo.cc:5:12: warning: unused variable 't' [-Wunused-variable]
  int r=a%b,t;
            ^
foo.cc: In function 'int main()':
foo.cc:41:6: warning: 'd' may be used uninitialized in this function [-Wmaybe-uninitialized]
  cout<<d;
  ~~~~^~~

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