# LeetCode 559. Maximum Depth of N-ary Tree

## Description

https://leetcode.com/problems/maximum-depth-of-n-ary-tree/

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, 104]`.

## Explanation

Traverse the tree and all the children nodes and record the maximum depth.

## Python Solution

``````"""
# 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:
self.max_depth = 0

self.traverse(root, 1)

return self.max_depth

def traverse(self, root, depth):
if not root:
return

self.max_depth = max(self.max_depth, depth)

for child in root.children:
self.traverse(child, depth + 1)
``````
• Time Complexity: O(N).
• Space Complexity: O(N).