/in/foo.cc: In function 'int main()':
/in/foo.cc:41:9: error: 'cin' was not declared in this scope
         cin >> x[i] ;
         ^~~
/in/foo.cc:48:13: error: 'cout' was not declared in this scope
             cout <<"i+1="<< i + 1 << ' '<<endl ;
             ^~~~
/in/foo.cc:48:43: error: 'endl' was not declared in this scope
             cout <<"i+1="<< i + 1 << ' '<<endl ;
                                           ^~~~
/in/foo.cc:52:5: error: 'cout' was not declared in this scope
     cout << endl ;
     ^~~~
/in/foo.cc:52:13: error: 'endl' was not declared in this scope
     cout << endl ;
             ^~~~