222 count complete tree nodes

def (self, root):
    """
    :type root: TreeNode
    :rtype: int
    """
    height = 0
    temp = root
    
    while temp != None:
        height += 1
        temp = temp.left
    return self.count(root, height)
        
def count(self, root, maxHeight):
    if root is None:
        return 0
    if root.left is None:
        return 1
    height = 0
    temp = root.left
    while temp != None:
        height += 1
        temp = temp.right
    if height == (maxHeight - 1): # left tree is perfect at the lowest level
        return pow(2, height) + self.count(root.right, maxHeight - 1)
    else: # right tree must be perfect at one level shallower
        return pow(2, height) + self.count(root.left, maxHeight - 1)