foo.cc: In function 'int main()':
foo.cc:8:2: error: 'cin' was not declared in this scope
  cin>>b>>d>>f;
  ^~~
foo.cc:8:2: note: suggested alternative: 'main'
  cin>>b>>d>>f;
  ^~~
  main
foo.cc:18:3: error: 'cout' was not declared in this scope
   cout<<h[z]<<" ";
   ^~~~
foo.cc:19:2: error: 'cout' was not declared in this scope
  cout<<endl;
  ^~~~
foo.cc:19:8: error: 'endl' was not declared in this scope
  cout<<endl;
        ^~~~
foo.cc:19:8: note: suggested alternative: 'enum'
  cout<<endl;
        ^~~~
        enum

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