LeetCode #429 N-ary Tree Level Order Traversal

Easy

Problem

Given an n-ary tree, return the level order traversal of its nodes’ values. (ie, from left to right, level by level).

For example, given a 3-ary tree:

We should return its level order traversal:

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

Note:

1. The depth of the tree is at most 1000.
2. The total number of nodes is at most 5000.

Solution

Just like in #102, use a queue for level tracking.

Complexity

Just like analytics of #102, it needs O(n) time and O(n) extra space if n denotes to counts of nodes in this tree.