forked from shuboc/LeetCode-2
-
Notifications
You must be signed in to change notification settings - Fork 0
/
average-of-levels-in-binary-tree.py
56 lines (51 loc) · 1.25 KB
/
average-of-levels-in-binary-tree.py
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
# Time: O(n)
# Space: O(h)
# 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:
# The range of node's value is in the range of 32-bit signed integer.
# Definition for a binary tree node.
# class TreeNode(object):
# def __init__(self, x):
# self.val = x
# self.left = None
# self.right = None
try:
xrange # Python 2
except NameError:
xrange = range # Python 3
class Solution(object):
def averageOfLevels(self, root):
"""
:type root: TreeNode
:rtype: List[float]
"""
result = []
q = [root]
while q:
total, count = 0, 0
next_q = []
for n in q:
total += n.val
count += 1
if n.left:
next_q.append(n.left)
if n.right:
next_q.append(n.right)
q = next_q
result.append(float(total) / count)
return result