Binary Tree Level Order Traversal — Medium Coding Interview Question

Given the root of a binary tree, return the level order traversal of its nodes' values (left to right, level by level), as an array of arrays.

Example

Input: root = [3,9,20,null,null,15,7]

Output: [[3],[9,20],[15,7]]

Constraints

• The number of nodes is in the range [0, 2000]
• -1000 ≤ Node.val ≤ 1000

Topics & Companies

Topics: trees

Asked by: Amazon, Meta, Microsoft, LinkedIn

Optimal Solution Complexity

Time complexity: O(n). Space complexity: O(n).

Practice more

• All DSA Problems
• DSA Patterns