Find length of circular linked list in kotlin

Kotlin program for Find length of circular linked list . Here problem description and other solutions.

// Kotlin program for
// Count number of nodes in circular linked list 

// Define class of linked list Node
class LinkNode
{
	var data: Int;
	var next: LinkNode ? ;
	constructor(data: Int, first: LinkNode ? )
	{
		this.data = data;
		this.next = first;
	}
}
class CircularLinkedList
{
	var head: LinkNode ? ;
	// Class constructor
	constructor()
	{
		this.head = null;
	}
	// Insert node at end of circular linked list
	fun insert(value: Int): Unit
	{
		// Create a new node
		val node: LinkNode = LinkNode(value, this.head);
		if (this.head == null)
		{
			// First node of linked list
			this.head = node;
			node.next = this.head;
		}
		else
		{
			var temp: LinkNode ? = this.head;
			// Find the last node
			while (temp?.next != this.head)
			{
				// Visit to next node
				temp = temp?.next;
			}
			// Add new node at the last 
			temp?.next = node;
		}
	}
	fun countNode(): Int
	{
		if (this.head == null)
		{
			return 0;
		}
		// Start with second node
		var temp: LinkNode ? = this.head?.next;
		// This is used to count linked node
		var count: Int = 1;
		// iterate circular linked list
		while (temp != this.head)
		{
			count += 1;
			// Visit to next node
			temp = temp?.next;
		}
		return count;
	}
}
fun main(args: Array < String > ): Unit
{
	val cll: CircularLinkedList = CircularLinkedList();
	// Add nodes
	cll.insert(1);
	cll.insert(3);
	cll.insert(5);
	cll.insert(7);
	cll.insert(9);
	cll.insert(11);
	// Display result
	println(cll.countNode());
}

Output

6