foo.cc: In function 'int main()':
foo.cc:12:12: warning: statement has no effect [-Wunused-value]
        n*10/b;
        ~~~~^~
foo.cc:17:10: error: expected '}' at end of input
  return 0; 
          ^

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