nnn

switch (x) {
                case 0 :  do { cout << " 0 " << endl;
                case 1 :         cout << " 1 " << endl;
                case 2 :         cout << " 2 " << endl;
                case 3 :         cout << " 3 " << endl;
                                   } while ( -- n > 0 );
 }