Level order traversal using queue in typescript

Ts program for Level order traversal using queue. Here more information.

/*
  TypeScript program for
  Level order tree traversal using queue
*/
// Create Q node
class QNode
{
	public data: TreeNode;
	public next: QNode;
	constructor(node: TreeNode)
	{
		this.data = node;
		this.next = null;
	}
}
// Binary Tree Node
class TreeNode
{
	public data: number;
	public left: TreeNode;
	public right: TreeNode;
	constructor(data: number)
	{
		// Set node value
		this.data = data;
		this.left = null;
		this.right = null;
	}
}
class MyQueue
{
	public head: QNode;
	public tail: QNode;
	public count: number;
	constructor()
	{
		this.head = null;
		this.tail = null;
		this.count = 0;
	}
	public number size()
	{
		return this.count;
	}
	public boolean isEmpty()
	{
		return this.count == 0;
	}
	// Add new node of queue
	public enqueue(value: TreeNode)
	{
		// Create a new node
		var node = new QNode(value);
		if (this.head == null)
		{
			// Add first element into queue
			this.head = node;
		}
		else
		{
			// Add node at the end using tail
			this.tail.next = node;
		}
		this.count++;
		this.tail = node;
	}
	// Delete a element into queue
	public dequeue()
	{
		if (this.head == null)
		{
			// Empty Queue
			return;
		}
		// Visit next node
		this.head = this.head.next;
		this.count--;
		if (this.head == null)
		{
			// When deleting a last node of linked list
			this.tail = null;
		}
	}
	// Get front node
	public TreeNode peek()
	{
		if (this.head == null)
		{
			return null;
		}
		return this.head.data;
	}
}
class BinaryTree
{
	public root: TreeNode;
	constructor()
	{
		// Set initial tree root
		this.root = null;
	}
	public levelOrder()
	{
		if (this.root != null)
		{
			var q = new MyQueue();
			// Add first node
			q.enqueue(this.root);
			var node = this.root;
			while (q.isEmpty() == false && node != null)
			{
				if (node.left != null)
				{
					// Add left child node
					q.enqueue(node.left);
				}
				if (node.right != null)
				{
					// Add right child node
					q.enqueue(node.right);
				}
				// Display level node
				console.log("  " + node.data);
				// Remove current node
				q.dequeue();
				// Get new head
				node = q.peek();
			}
		}
		else
		{
			console.log("Empty Tree");
		}
	}
	public static main(args: string[])
	{
		// Create new tree
		var tree = new BinaryTree();
		/*
		  Make A Binary Tree
		  -----------------------
		         1
		       /   \
		      2     3
		     /     / \
		    4     5   6
		   /     / \
		  7     8   9
		*/
		// Adding tree nodes
		tree.root = new TreeNode(1);
		tree.root.left = new TreeNode(2);
		tree.root.right = new TreeNode(3);
		tree.root.right.right = new TreeNode(6);
		tree.root.right.left = new TreeNode(5);
		tree.root.left.left = new TreeNode(4);
		tree.root.left.left.left = new TreeNode(7);
		tree.root.right.left.left = new TreeNode(8);
		tree.root.right.left.right = new TreeNode(9);
		// Display level order  element
		tree.levelOrder();
	}
}
BinaryTree.main([]);
/*
 file : code.ts
 tsc --target es6 code.ts
 node code.js
 */

Output

  1
  2
  3
  4
  5
  6
  7
  8
  9



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