/in/foo.cc: In function 'int main()':
/in/foo.cc:4:11: error: 'cin' was not declared in this scope
     while(cin>>n)
           ^~~
/in/foo.cc:4:11: note: suggested alternative: 'main'
     while(cin>>n)
           ^~~
           main
/in/foo.cc:13:9: error: 'cout' was not declared in this scope
         cout<<setiosflags(ios::fixed)<<setprecision(2)<<ave_score<<" ";
         ^~~~
/in/foo.cc:13:27: error: 'ios' has not been declared
         cout<<setiosflags(ios::fixed)<<setprecision(2)<<ave_score<<" ";
                           ^~~
/in/foo.cc:13:15: error: 'setiosflags' was not declared in this scope
         cout<<setiosflags(ios::fixed)<<setprecision(2)<<ave_score<<" ";
               ^~~~~~~~~~~
/in/foo.cc:13:40: error: 'setprecision' was not declared in this scope
         cout<<setiosflags(ios::fixed)<<setprecision(2)<<ave_score<<" ";
                                        ^~~~~~~~~~~~
/in/foo.cc:16:24: error: 'endl' was not declared in this scope
         cout << ave << endl ;
                        ^~~~
/in/foo.cc:16:24: note: suggested alternative: 'enum'
         cout << ave << endl ;
                        ^~~~
                        enum