Binary Tree Level Order Traversal is an example of null problems. In this post we will see how we can solve in Javascript.

Problem Description

Given a binary tree, return the level order traversal of its nodes' values. (ie, from left to right, level by level).

For example:

Given binary tree [3,9,20,null,null,15,7],

3

/ \

9 20

/  \

15 7

return its level order traversal as:

[

[3],

[9,20],

[15,7]

]

If you have different approach in mind or have any suggestion for this implementation feel free to share in the comment below. Thanks!