leetcode1161

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

import sys
class Solution:
    # 返回二维列表[[1,2],[4,5]]
    def __init__(self):
        self.list = []
        self.result = []
        
    def levelOrder(self,level):
        count = len(level)
        while count > 0:
            root = level.pop(0)
            self.list.append(root.val)
            if root.left != None:
                level.append(root.left)
            if root.right != None:
                level.append(root.right)
            count -= 1
        if len(self.list) > 0:
            self.result.append(self.list[:])
            self.list = []
        if len(level) > 0:
            self.levelOrder(level)
            
    # write code here
    def maxLevelSum(self, root: TreeNode) -> int:
        if root == None:
            return self.list
        else:
            level = []
            level.append(root)
            self.levelOrder(level)
            maxval = -sys.maxsize
            maxlevel = -1
            for i in range(len(self.result)):
                curlevelsum = sum(self.result[i])
                if curlevelsum > maxval:
                    maxval = curlevelsum
                    maxlevel = i + 1
            return maxlevel
        

算法思路：二叉树层次遍历