水题，递归遍历childern，判断高度最大的那个返回即可。
代码如下：
""" # Definition for a Node. class Node(object): def __init__(self, val, children): self.val = val self.children = children """ class Solution(object): def maxDepth(self, root): """ :type root: Node :rtype: int """ if root == None: return 0 result = 1 for child in root.children: temp = self.maxDepth(child) if result < temp+1: result =temp+1 return result
