# Longest ZigZag Path in a Binary Tree

Category

Binary Tree - DFS

Checkbox

Checkbox

Difficulty

Medium

Index

37

Key Ideas

The key idea to solve this problem is to perform a depth-first search (DFS) on the binary tree, keeping track of the longest zigzag path at each node.

Problem Number

1372

Problem Summary

The problem "Longest ZigZag Path in a Binary Tree" is a medium difficulty problem in the category of Binary Tree - DFS. The goal is to find the length of the longest ZigZag path in a binary tree, where a ZigZag path alternates between left and right child nodes. Key pitfalls to watch out for include properly tracking the length of the ZigZag path and handling cases where the path starts or ends at the root node.

Solution Summary

The best solution to find the longest ZigZag path in a binary tree involves a depth-first search (DFS) approach. We can define two separate functions to traverse the tree in both left and right directions. During the traversal, we keep track of the longest ZigZag path length for each node. By comparing the lengths of left and right paths, we update the maximum ZigZag path length. This solution utilizes dynamic programming principles to efficiently calculate the longest ZigZag path. It is crucial to carefully implement the traversal and update logic to ensure accurate results.

Tags

Dynamic Programming

Tree

Depth-First Search