题目
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.
解题思路
代码
# Definition for a binary tree node.
# class TreeNode:
# def __init__(self, x):
# self.val = x
# self.left = None
# self.right = None
class Solution:
res = 0
def diameterOfBinaryTree(self, root: TreeNode) -> int:
def dfs(root):
if not root:
return 0
l = dfs(root.left)
r = dfs(root.right)
self.res = max(self.res, l + r)
return max(l, r) + 1
if not root:
return 0
dfs(root)
return self.res
