Learn
Never written code before? Start here. Each lesson is short, and you can run and edit every example right on the page — no setup, nothing to install. When you're ready, these lead straight into AlgoArena's practice problems.
Write and run your very first lines of Python — right here on the page.
5 min · Python
Store values in named boxes called variables, then reuse them.
6 min · Python
Use Python as a calculator — and do math with your variables.
6 min · Python
Join text together, measure it, and change its case.
7 min · Python
Hold many values under one name, and reach for the one you want.
7 min · Python
Run different code depending on whether something is true.
8 min · Python
Repeat work without writing it out a hundred times.
8 min · Python
Package code under a name so you can reuse it.
9 min · Python
Explore the surprising benefits of competitive programming: faster thinking, better code, and skills that transfer directly to your day job.
A beginner-friendly guide to analyzing algorithm efficiency and understanding Big O, Omega, and Theta notation.
Discover what competitive programming is, why it's valuable for your career, and how to get started on your journey to becoming a better problem solver.
Practical advice from experienced developers on how to approach coding interviews, manage time, and communicate effectively.
A comprehensive guide to binary search algorithms, covering standard search, rotated arrays, and finding boundaries.
Comprehensive coverage of tree data structures, including DFS, BFS, tree construction, and common interview problems.
Practical, battle-tested advice for acing coding interviews. From problem-solving strategies to communication tips that impress interviewers.
Explore depth-first search and breadth-first search algorithms with visual examples and implementation details.
Learn from others' failures. These are the most common mistakes candidates make in coding interviews and exactly how to avoid them.
Introduction to system design principles, covering load balancing, caching, databases, and distributed systems fundamentals.
When to reach for a heap, the classic patterns (top K, merging streams, scheduling), and Python/Java/C++ mental models.
Understand the fundamentals of dynamic programming with clear examples and when to use memoization vs bottom-up approaches.
A strategic roadmap for landing your dream job at top tech companies. Covers what to study, how to practice, and what interviewers really look for.
Learn how to identify and solve sliding window problems efficiently. Includes common patterns and practice problems.
Learn how to solve the classic Two Sum problem using brute force, hash maps, and two-pointer techniques. Perfect for interview prep.
Deep dive into backtracking algorithms with examples including permutations, combinations, and constraint satisfaction problems.