Print all odd nodes of Binary Search Tree in swift

Swift program for Print all odd nodes of Binary Search Tree. Here more solutions.

import Foundation
// Swift 4 program for
// Detect and print all leaf nodes in binary search tree

// Binary Search Tree Node
class TreeNode
{
	// Data value
	var data: Int;
	// Indicates left and right subtree
	var left: TreeNode? ;
	var right: TreeNode? ;
	init(_ data: Int)
	{
		self.data = data;
		self.left = nil;
		self.right = nil;
	}
}
class BinarySearchTree
{
	var root: TreeNode? ;
	init()
	{
		self.root = nil;
	}
	// Insert a node in BST
	func addNode(_ value: Int)
	{
		// Create new node of binary search tree
		let node: TreeNode? = TreeNode(value);
		if (node  != nil)
		{
			if (self.root == nil)
			{
				// When adds a first node in binary tree
				self.root = node;
			}
			else
			{
				var find: TreeNode? = self.root;
				// Add new node to proper position
				while (find  != nil)
				{
					if (find!.data >= value)
					{
						if (find!.left == nil)
						{
							find!.left = node;
							return;
						}
						else
						{
							// Visit left sub-tree
							find = find!.left;
						}
					}
					else
					{
						if (find!.right == nil)
						{
							find!.right = node;
							return;
						}
						else
						{
							// Visit right sub-tree
							find = find!.right;
						}
					}
				}
			}
		}
		else
		{
			print("\nMemory Overflow");
		}
	}
	// Display the value of odd nodes in binary search tree
	func printOddNode(_ node: TreeNode? )
	{
		if (node  != nil)
		{
			// Visit to left child
			self.printOddNode(node!.left);
			if (node!.data % 2  != 0)
			{
				// When node contain odd value
				print(node!.data, terminator: "  ");
			}
			// Visit to right child
			self.printOddNode(node!.right);
		}
	}
	static func main()
	{
		let tree: BinarySearchTree = BinarySearchTree();
		// Add nodes in binary search tree
		/*
		            5
		           / \
		          /   \ 
		         /     \
		        3       9
		       / \     / \
		      1   4   8   11
		     / \     /      \
		   -3   2   6        12
		        
		*/
		tree.addNode(5);
		tree.addNode(3);
		tree.addNode(9);
		tree.addNode(1);
		tree.addNode(4);
		tree.addNode(8);
		tree.addNode(11);
		tree.addNode(-3);
		tree.addNode(2);
		tree.addNode(6);
		tree.addNode(12);
		// Test
		tree.printOddNode(tree.root);
	}
}
BinarySearchTree.main();

Output

-3  1  3  5  9  11