Create the doubly linked list : 8 < -> 4 < -> 4 < -> 6 < -> 4 < -> 8 < -> 4 < -> 10 < -> 12 < -> 12
head = push ( head , 12 ) ; head = push ( head , 12 ) ; head = push ( head , 10 ) ; head = push ( head , 4 ) ; head = push ( head , 8 ) ; head = push ( head , 4 ) ; head = push ( head , 6 ) ; head = push ( head , 4 ) ; head = push ( head , 4 ) ; head = push ( head , 8 ) ; document . write ( " " ) ; printList ( head ) ;