Learn JavaScript Data Structures & Algorithms Visually - Volume 2

Stop memorizing solutions. Start seeing why they work.

Learn JavaScript Data Structures & Algorithms Visually - Volume 2 brings together 108 algorithms covering trees, linked lists, strings, and arrays, each part opened by short foundation sections on the core tree patterns, the pointers you must track, the string and character toolkit, off-by-one errors, and two pointers. Every algorithm is shown in full color, so nodes, pointers, windows, and changing values stand apart at a glance and are easy to trace.

Mirror trees and turn sorted lists into balanced BSTs. Find exactly where a linked-list cycle begins. Count palindromes and compute edit distance, then build magic squares and minimum-cost paths. Instead of holding every intermediate step in your head, follow the execution on the page.

The visual walkthroughs use small multiples, a data visualization technique that presents successive stages of an algorithm as a series of consistently structured diagrams. By seeing meaningful stages together, you can compare states, follow what moves, and understand how each decision affects the next. This brings the algorithm to life, reinforcing understanding and helping the underlying patterns and mechanics stay with you longer.

Every main algorithm is presented in three complementary parts:

Understanding & Reasoning: Learn the goal, key idea, edge cases, and time and space complexity before studying the implementation.

Inspect & Debug: Examine JavaScript code alongside an AI-Era Interview Lens that challenges you to question assumptions, recognize plausible mistakes, and explain why a solution is correct.

Trace & Walkthrough: Follow the input through intermediate states to the result, with visual explanations of the decisions that matter.

Most interview bugs aren't in the big idea - they hide in a pointer moved one step too soon, an index off by one, a window that never shrinks. This book is about seeing the state clearly enough that those bugs have nowhere to hide.

Every code sample was compiled, tested against edge cases beyond what's printed on the page, and independently reviewed before making it into the book.

Designed for readers with basic JavaScript knowledge who want to strengthen coding interview preparation, debugging, and algorithmic reasoning.

This is Volume 2 of a four-volume JavaScript algorithm collection containing 430 algorithms across trees, linked lists, strings, and arrays.

Understand the idea. Follow the state. Explain the result.