Java: How to Assign Node Height

    public static int assignHeight(node n)
    {
        if(n == null)
        {
            return -1;
        }
        int hL;
        int hR;
        hL = assignHeight(n.left)+1;
        hR = assignHeight(n.right)+1;
        n.height = Math.max(hL, hR);
        return n.height;
    }