## Algorithm

Problem Name: 429. N-ary Tree Level Order Traversal

Given an n-ary tree, return the level order traversal of its nodes' values.

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: [[1],[3,2,4],[5,6]]
```

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: [[1],[2,3,4,5],[6,7,8,9,10],[11,12,13],[14]]
```

Constraints:

• The height of the n-ary tree is less than or equal to `1000`
• The total number of nodes is between `[0, 104]`

## Code Examples

### #1 Code Example with Java Programming

```Code - Java Programming```

``````
class Solution {
public List();
}
List();
Queue queue = new LinkedList<>();
while (!queue.isEmpty()) {
int size = queue.size();
List < Integer> currLevel = new ArrayList<>();
while (size-- > 0) {
Node removed = queue.remove();
}
}
return levels;
}
}
``````
Copy The Code &

Input

cmd
root = [1,null,3,2,4,null,5,6]

Output

cmd
[[1],[3,2,4],[5,6]]

### #2 Code Example with Javascript Programming

```Code - Javascript Programming```

``````
const levelOrder = function(root) {
const res = []
if(root == null) return res
helper(root, 0, res)
return res
};

function helper(node, index, res) {
if(node == null) return
if(res[index] == null) res[index] = []
res[index].push(node.val)
for(let i = 0, len = node.children.length; i < len; i++) {
helper(node.children[i], index + 1, res>
}
}
``````
Copy The Code &

Input

cmd
root = [1,null,3,2,4,null,5,6]

Output

cmd
[[1],[3,2,4],[5,6]]

### #3 Code Example with C# Programming

```Code - C# Programming```

``````
using System.Collections.Generic;

namespace LeetCode
{
public class _0429_NAryTreeLevelOrderTraversal
{
public IList < IList<int>> LevelOrder(Node root)
{
var results = new List < IList<int>>();
if (root == null) return results;

var queue = new Queue < Node>();
queue.Enqueue(root);

while (queue.Count > 0)
{
var size = queue.Count;
var result = new List < int>();
for (int i = 0; i  <  size; i++)
{
var node = queue.Dequeue();
if (node.children != null)
foreach (var child in node.children)
queue.Enqueue(child);
}

}

return results;
}

public class Node
{
public int val;
public IList < Node> children;

public Node() { }

public Node(int _val)
{
val = _val;
}

public Node(int _val, IList < Node> _children)
{
val = _val;
children = _children;
}
}
}
}
``````
Copy The Code &

Input

cmd
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

cmd
[[1],[2,3,4,5],[6,7,8,9,10],[11,12,13],[14]]