Description
Given a n-ary tree, find its maximum depth.
The maximum depth is the number of nodes along the longest path from the root node down to the farthest leaf node.
Nary-Tree input serialization is represented in their level order traversal, each group of children is separated by the null value (See examples).
Example 1:
Input: root = [1,null,3,2,4,null,5,6]
Output: 3
Example 2:
Input: root = [1,null,2,3,4,5,null,null,6,7,null,8,null,9,10,null,null,11,null,12,null,13,null,null,14]
Output: 5
Constraints:
- The depth of the n-ary tree is less than or equal to 1000.
- The total number of nodes is between [0, 10^4].
分析
题目的意思是：给你一个n叉树，求最大的深度，好久没有写关于树的算法了，前一段时间面试就写过几个，比较生疏，看来需要补补功课了。这道题中规中矩，关键是要遍历跟节点的所有叶子结点，找出最大值就行了。
代码
"""
# Definition for a Node.
class Node:
def __init__(self, val=None, children=None):
self.val = val
self.children = children
"""
class Solution:
def maxDepth(self, root: 'Node') -> int:
if(root is None):
return 0
if(root.children is None):
return 1
res=0
for node in root.children:
res=max(res,self.maxDepth(node))
return res+1
参考文献
[LeetCode] Python DFS
