LeetCode-222. Count Complete Tree Nodes

https://leetcode.com/problems/count-complete-tree-nodes/

Given a complete binary tree, count the number of nodes.

Definition of a complete binary tree from Wikipedia:
In a complete binary tree every level, except possibly the last, is completely filled, and all nodes in the last level are as far left as possible. It can have between 1 and 2h nodes inclusive at the last level h.

Solution

参考：https://discuss.leetcode.com/topic/15533/concise-java-solutions-o-log-n-2

# Definition for a binary tree node.
# class TreeNode(object):
#     def __init__(self, x):
#         self.val = x
#         self.left = None
#         self.right = None

class Solution(object):
    def countNodes(self, root):
        """
        :type root: TreeNode
        :rtype: int
        """
        count = 0
        while root:
            l = self.getHeight(root.left)
            r = self.getHeight(root.right)
            if l == r:
                count += 2**l
                root = root.right
            else:
                count += 2**r
                root = root.left
        return count
        
    def getHeight(self, root):
        h = 0
        while root:
            h += 1
            root = root.left
        return h
    

不是完全二叉树的情况呢？？