#!/user/bin/env python

# coding=utf-8

"""

@project : algorithmPython

@ide : PyCharm

@file : levelOrderBottom

@author : illusion

@desc : 107. 二叉树的层次遍历 II https://leetcode-cn.com/problems/binary-tree-level-order-traversal-ii/

@create : 2020-07-26 15:55:32

"""

class TreeNode:

def __init__(self, x):

self.val = x

self.left = None

self.right = None

class Solution:

def levelOrderBottom(self, root: TreeNode) -> [[int]]:

result = self.levelOrder(root)

result.reverse()

return result

def levelOrder(self, root: TreeNode) -> [[int]]:

result = []

if not root:

return result

queue = [root]

while len(queue):

list = []

for i in range(len(queue)):

level = queue[0]

queue = queue[1:]

list.append(level.val)

if level.left:

queue.append(level.left)

if level.right:

queue.append(level.right)

result.append(list)

return result