Method padList

java/Chapter 2/Question2_5/QuestionB.java:43–52

(LinkedListNode l, int padding)

	}	
	
	private static LinkedListNode padList(LinkedListNode l, int padding) {
		LinkedListNode head = l;
		for (int i = 0; i < padding; i++) {
			LinkedListNode n = new LinkedListNode(0, null, null);
			head.prev = n;
			n.next = head;
			head = n;
		}
		return head;
	}
	
	private static LinkedListNode insertBefore(LinkedListNode list, int data) {
		LinkedListNode node = new LinkedListNode(data, null, null);