/
Solution.py
95 lines (50 loc) · 1.47 KB
/
Solution.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
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
"""
Given a binary tree, find the length of the longest path where each node in the path has the same value. This path may or may not pass through the root.
Note: The length of path between two nodes is represented by the number of edges between them.
Example 1:
Input:
5
/ \
4 5
/ \ \
1 1 5
Output:
2
Example 2:
Input:
1å
/ \
4 5
/ \ \
4 4 5
Output:
2
Note: The given binary tree has not more than 10000 nodes. The height of the tree is not more than 1000.
"""
# Definition for a binary tree node.
class TreeNode:
def __init__(self, x):
self.val = x
self.left = None
self.right = None
class Solution:
def longestUnivaluePath(self, root):
"""
:type root: TreeNode
:rtype: int
"""
if not root:
return 0
longpath = 0
def maxpath(root):
nonlocal longpath
if not root:
return 0
left = maxpath(root.left)
right = maxpath(root.right)
left = left + 1 if root.left and root.left.val == root.val else 0
right = right + 1 if root.right and root.right.val == root.val else 0
longpath = max(longpath,left + right)
return max(left,right)
maxpath(root)
return longpath