Thread: Distance between root and leaf.

Hi,
I wrote the following recursion for finding the distance between a root and a leaf, but am not quite sure how to make it work. Could anyone advise?

Code:

int calc_depth(Node* tree, Node* zero)
{
	if (!tree)
		return 0; 
	if (zero->right || zero->left == tree)
		return 1;
	return (zero->right ? calc_depth(tree, zero->right) : calc_depth(tree, zero->left));
}