LinkedListNode.java

package techQuestions;

// Erich's LinkedListNode public class for many Cracking the
// Coding Interview Questions

public class LinkedListNode {
	public LinkedListNode prev, next, last;
	// node will contain integer data type
	public int data;
	public LinkedListNode(int d, LinkedListNode n, LinkedListNode p) {
		data = d;
		setNext(n);
		setPrevious(p);
	}
	
	public LinkedListNode(int d) {
		data = d;
	}
	
	public LinkedListNode() {}
	
	public void setNext(LinkedListNode n) {
		next = n;
		if (this == last) {
			last = n;
		}
		if (n != null && n.prev != this) {
			n.setPrevious(this);
		}
	}
	
	public void setPrevious(LinkedListNode p) {
		prev = p;
		if (p != null && p.next != this) {
			p.setNext(this);
		}
	}
	
	public LinkedListNode clone() {
		LinkedListNode next2 = null;
		if (next != null) {
			next2 = next.clone();
		}
		LinkedListNode head2 = new LinkedListNode(data, next2, null);
		return head2;
	}
}