Grokking the Coding Interview: Patterns for Coding Questions

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Solution: Reverse Level Order Traversal

Problem Statement

Given a binary tree, populate an array to represent its level-by-level traversal in reverse order, i.e., the lowest level comes first. You should populate the values of all nodes in each level from left to right in separate sub-arrays.

Example 1:

Example 2:

Constraints:

The number of nodes in the tree is in the range [0, 2000].
-1000 <= Node.val <= 1000

Solution

This problem follows the Binary Tree Level Order Traversal pattern. We can follow the same BFS approach

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