0429. N-ary Tree Level Order Traversal

https://leetcode.com/problems/n-ary-tree-level-order-traversal

Description

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]

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