public static DoublyLinkedListNode reverse(DoublyLinkedListNode llist) {
        DoublyLinkedListNode reversedList = null, current = llist;
        
        while (current != null) {
            DoublyLinkedListNode temp = new DoublyLinkedListNode(current.data);
            
            if (reversedList == null) {
                reversedList = temp;
            } else {
                temp.next = reversedList;
                reversedList.prev = temp;
                reversedList = reversedList.prev;
            }
            current = current.next;
        }
        
        return reversedList;
    }