Compute height of a binary tree

A very easy and neat way to compute height of tree is using recursive function.

private int height(Node node) {
	if (null == node)
		return 0;
	else {
		return (1 + Math.max(height(node.left), height(node.right)));
	}
}

public int height() {
	return height(root);
}

As an alternative, we can use iterative way to compute it. Here, I used the breadth first to compute height of a tree.

public int iterativeHeight() {
	int rvl = 0;
	int numNode = 0;
	Node node = root;
	// queue
	LinkedList> que = new LinkedList();
	que.addLast(node);
	numNode = 1; // in root level
	while (!que.isEmpty()) {
		rvl++;
		int localNum = 0; //record how many node added in level
		for (; numNode > 0; numNode--) {
			node = que.removeFirst();
			if (node.right != null) {
				que.addLast(node.right);
				localNum++;
			}
			if (node.left != null) {
				que.addLast(node.left);
				localNum++;
			}
		}
		numNode = localNum;
	}
	return rvl;
}