我最喜欢的Leetcode经典问题合集

leetcode数列求和leetcode我最喜欢的Leetcode问题合集

1. 计算完整的树节点 lg(N) * lg(N)

# 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):

    count = 0

    def countNodes(self, root):

        \"\"\"

        :type root: TreeNode

        :rtype: int

        \"\"\"

        if not root:

            return 0

        left_depth = self.traverse(root.left)

        right_depth = self.traverse(root.right)

        if left_depth:

            return 2 ** left_depth + self.countNodes(root.right)