标签:range sign ret exp one res binary pop none
Given a non-empty binary tree, return the average value of the nodes on each level in the form of an array.
Example 1:
Input:
3
/
9 20
/
15 7
Output: [3, 14.5, 11]
Explanation:
The average value of nodes on level 0 is 3, on level 1 is 14.5, and on level 2 is 11. Hence return [3, 14.5, 11].
Note:
# Definition for a binary tree node.
class TreeNode:
def __init__(self, x):
self.val = x
self.left = None
self.right = None
class Solution:
def averageOfLevels(self, root):
"""
:type root: TreeNode
:rtype: List[float]
"""
if root is None:
return []
temp = [root]
res = []
while len(temp):
l = len(temp)
ans = 0
for _ in range(l):
ans += temp[0].val
if temp[0].left:
temp.append(temp[0].left)
if temp[0].right:
temp.append(temp[0].right)
temp.pop(0)
res.append(ans/l)
return res
637. Average of Levels in Binary Tree
标签:range sign ret exp one res binary pop none
原文地址:https://www.cnblogs.com/bernieloveslife/p/9813419.html