Bottom right view of binary tree in scala

Scala program for Bottom right view of binary tree. Here problem description and other solutions.

import scala.collection.mutable._;
/* 
  Scala program for
  Print bottom-right view of a binary tree
*/
// Binary Tree Node
class TreeNode(var data: Int,
	var left: TreeNode,
		var right: TreeNode)
{
	def this(data: Int)
	{
		// Set node value
		this(data, null, null);
	}
}
class BinaryTree(var root: TreeNode)
{
	def this()
	{
		this(null);
	}
	// Find bottom right elements
	def bottomRightView(node: TreeNode, 
                        distance: Int, 
                        record: HashMap[Int, Int]): Unit = {
		if (node != null)
		{
			// Add node of specific distance.
			// This is adding a new element or
			// update existing value
			record.addOne(distance, node.data);
			// Visit left subtree And
			// Here increase the distance by 1
			bottomRightView(node.left, distance + 1, record);
			// Visit to right subtree
			bottomRightView(node.right, distance, record);
		}
	}
	def printBottomRight(): Unit = {
		// This is store result
		var record: HashMap[Int, Int] = new HashMap[Int, Int]();
		bottomRightView(this.root, 0, record);
		var distance: Int = 0;
		while (distance < record.size)
		{
			// Display bottom right element
			print("  " + record.get(distance).get);
			distance += 1;
		}
	}
}
object Main
{
	def main(args: Array[String]): Unit = {
		// Create new tree
		var tree: BinaryTree = new BinaryTree();
		/*
		  Binary Tree
		  -----------------------
		      10
		     /  \
		    2    4
		   /    / \
		  3    6   5
		        \
		         7
		       /  \
		      8    11

		       
		            [⤣⤣⤣⤣]
		            View position
		*/
		// Add node
		tree.root = new TreeNode(10);
		tree.root.left = new TreeNode(2);
		tree.root.left.left = new TreeNode(3);
		tree.root.right = new TreeNode(4);
		tree.root.right.right = new TreeNode(5);
		tree.root.right.left = new TreeNode(6);
		tree.root.right.left.right = new TreeNode(7);
		tree.root.right.left.right.left = new TreeNode(8);
		tree.root.right.left.right.right = new TreeNode(11);
		// Test
		tree.printBottomRight();
	}
}

Output

  5  11  8