c# csharp

solution that doesn't use recursion

private static int getHeight(Node root)
{
    if (root == null)
    {
        return -1; // height of empty tree is -1
    }

    Queue<Node> queue = new Queue<Node>();
    queue.Enqueue(root);
    int height = -1;

    while (queue.Count > 0)
    {
        int nodeCount = queue.Count;  // Number of nodes at the current level
        height++;

        // Process each node at the current level
        while (nodeCount > 0)
        {
            Node node = queue.Dequeue();

            // Enqueue left and right children of the current node
            if (node.left != null)
            {
                queue.Enqueue(node.left);
            }
            if (node.right != null)
            {
                queue.Enqueue(node.right);
            }

            nodeCount--;
        }
    }

    return height;
}