# 429-n-ary-tree-level-order-traversal


Try it on <a href='https://leetcode.com/problems/429-n-ary-tree-level-order-traversal'>leetcode</a>

## Description
<div class="description">
<div><p>Given an n-ary tree, return the <em>level order</em> traversal of its nodes' values.</p>

<p><em>Nary-Tree input serialization is represented in their level order traversal, each group of children is separated by the null value (See examples).</em></p>

<p>&nbsp;</p>
<p><strong>Example 1:</strong></p>

<p><img src="https://assets.leetcode.com/uploads/2018/10/12/narytreeexample.png" style="width: 100%; max-width: 300px;"></p>

<pre><strong>Input:</strong> root = [1,null,3,2,4,null,5,6]
<strong>Output:</strong> [[1],[3,2,4],[5,6]]
</pre>

<p><strong>Example 2:</strong></p>

<p><img alt="" src="https://assets.leetcode.com/uploads/2019/11/08/sample_4_964.png" style="width: 296px; height: 241px;"></p>

<pre><strong>Input:</strong> 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]
<strong>Output:</strong> [[1],[2,3,4,5],[6,7,8,9,10],[11,12,13],[14]]
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li>The height of the n-ary tree is less than or equal to <code>1000</code></li>
	<li>The total number of nodes is between <code>[0, 10<sup>4</sup>]</code></li>
</ul>
</div>
</div>

## Solution(Python)
```Python
"""
# Definition for a Node.
class Node:
    def __init__(self, val=None, children=None):
        self.val = val
        self.children = children
"""

class Solution:
    def levelOrder(self, root: 'Node') -> List[List[int]]:
        if not root:
            return []
        
        q = deque([root])
        res = []
        while q:
            n = len(q)
            cur_level = []
            for _ in range(n):
                node = q.popleft()
                if node:
                    cur_level.append(node.val)
                    for child in node.children:
                        q.append(child)
            res.append(cur_level)
        return res
                    
```