Recursion, Backtracking & Dynamic Programming - Kotlin Edition

Stop memorizing recurrences. Start seeing why they work.

Recursion, Backtracking & Dynamic Programming - Kotlin Edition teaches 50 recursion, backtracking, and dynamic programming algorithms through plain-language explanations, Kotlin implementations, and step-by-step visual walkthroughs - from N-Queens and minimax to knapsack, edit distance, and interval DP. Every algorithm is shown in full color, so call stacks, choices, and DP tables stand apart at a glance and are easy to trace.

Watch a recursion tree unfold call by call. Follow backtracking as it makes a choice, explores it, and undoes it. See a DP table fill cell by cell, and track exactly which earlier answer each new one depends on. Instead of holding every call 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 Kotlin 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.

Recursive solutions rarely fail in the recurrence - they fail at the edges: a base case that returns the wrong identity, a choice that never gets undone, a memo that remembers the wrong state. This book is about building the instincts that keep every call honest.

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 Kotlin knowledge who want to strengthen coding interview preparation, debugging, and algorithmic reasoning.

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