Given a binary tree, you need to compute the length of the diameter of the tree. The diameter of a binary tree is the length of the longest path between any two nodes in a tree. This path may or may not pass through the root.
Example:
Given a binary tree
1
/ 2 3
/ \
4 5
Return 3, which is the length of the path [4,2,1,3] or [5,2,1,3].
Note: The length of path between two nodes is represented by the number of edges between them.
# Definition for a binary tree node.
# class TreeNode(object):
# def __init__(self, x):
# self.val = x
# self.left = None
# self.right = None
class Solution(object):
def diameterOfBinaryTree(self, root):
"""
:type root: TreeNode
:rtype: int
"""
self.ans=1
def dfs(node):
if not node:
return 0
L=dfs(node.left)
R=dfs(node.right)
self.ans=max(self.ans,L+R+1)
return max(L,R)+1
dfs(root)
return self.ans-1
[LeetCode&Python] Problem 543. Diameter of Binary Tree
原文：https://www.cnblogs.com/chiyeung/p/10090227.html