reverse a doubly circular linked list by swapping node value in c#

Csharp program for reverse a doubly circular linked list by swapping node value. Here more information.

// Include namespace system
using System;
/*
  Csharp Program
  Reverse a doubly circular linked list by swapping value
*/
// Linked list node
public class LinkNode
{
	public int data;
	public LinkNode next;
	public LinkNode back;
	public LinkNode(int data, LinkNode back, LinkNode next)
	{
		this.data = data;
		this.back = back;
		this.next = next;
	}
}
public class CircularDoublyLL
{
	public LinkNode front;
	public LinkNode tail;
	public CircularDoublyLL()
	{
		this.front = null;
		this.tail = null;
	}
	// Add new node at the end of linked list
	public void addNode(int data)
	{
		var node = new LinkNode(data, null, null);
		// When new node is successfully created
		if (this.front == null)
		{
			// Add first node of linked list
			this.front = node;
			this.tail = node;
		}
		else
		{
			// Add node at last position
			this.tail.next = node;
			node.back = this.tail;
			this.tail = node;
		}
		// Connect the last node in the linked list to front
		this.tail.next = this.front;
		this.front.back = this.tail;
		// Set node data
		node.data = data;
	}
	// Print linked list nodes
	public void printElement()
	{
		if (this.front == null)
		{
			Console.Write("\n Empty Linked List \n");
		}
		else
		{
			var temp = this.front;
			Console.Write("\n Linked List from Front to Tail \n");
			// Display doubly linked list from start to last node
			while (temp != null)
			{
				Console.Write("  " + temp.data.ToString());
				if (temp == this.tail)
				{
					// When get last node
					temp = null;
				}
				else
				{
					temp = temp.next;
				}
			}
			temp = this.tail;
			Console.Write("\n Linked List from Tail to Front \n");
			// Display doubly linked list from last to start node
			while (temp != null)
			{
				Console.Write("  " + temp.data.ToString());
				if (temp == this.front)
				{
					// When get first node
					temp = null;
				}
				else
				{
					temp = temp.back;
				}
			}
		}
	}
	// Reverses the elements of doubly linked list
	// using swap node values
	public void reverseElement()
	{
		// Get first node
		var first = this.front;
		// Get last node
		var last = this.tail;
		var temp = 0;
		// Reverse operation
		while (first != null && last != null)
		{
			if (first != last)
			{
				// Swap the node value
				temp = first.data;
				first.data = last.data;
				last.data = temp;
				if (first.next == last)
				{
					// Stop reverse operation, or use break
					first = null;
					last = null;
				}
				else
				{
					first = first.next;
					last = last.back;
				}
			}
			else
			{
				// Stop reverse operation, or use break
				first = null;
				last = null;
			}
		}
	}
	public static void Main(String[] args)
	{
		var cll = new CircularDoublyLL();
		// Add linked list node
		cll.addNode(1);
		cll.addNode(2);
		cll.addNode(3);
		cll.addNode(4);
		cll.addNode(5);
		cll.addNode(6);
		Console.Write("\n Before reverse linked list");
		cll.printElement();
		cll.reverseElement();
		Console.Write("\n\n After reverse linked list");
		cll.printElement();
	}
}

Output

 Before reverse linked list
 Linked List from Front to Tail
  1  2  3  4  5  6
 Linked List from Tail to Front
  6  5  4  3  2  1

 After reverse linked list
 Linked List from Front to Tail
  6  5  4  3  2  1
 Linked List from Tail to Front
  1  2  3  4  5  6