Grokking the Coding Interview: Patterns for Coding Questions

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Solution: Zigzag Traversal

Problem Statement

Given a binary tree, populate an array to represent its zigzag level order traversal. You should populate the values of all nodes of the first level from left to right, then right to left for the next level and keep alternating in the same manner for the following levels.

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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