Leetify for CSES

A modern, Leetcode-style workspace for solving CSES problems.

Leetify for CSES Turn CSES into a modern competitive programming workspace. CSES is one of the best collections of algorithm and data structure problems for competitive programming—but its interface has remained intentionally minimal. Leetify for CSES transforms the familiar CSES experience into a modern, distraction-free workspace inspired by today's best coding platforms, without changing how CSES works. Enjoy a resizable split-pane layout, a VS Code-powered Monaco Editor, automatic code saving, built-in test case execution, dark mode, and a streamlined workflow—all directly on cses.fi. No accounts. No setup. No third-party website. Just a better way to solve CSES problems. ──────────────────────────────────────── Why Leetify for CSES? If you regularly practice on platforms like LeetCode, Codeforces, or AtCoder, switching back to CSES can feel limiting. The default editor is minimal, progress can be interrupted, and managing test cases often means juggling multiple windows or external editors. Leetify for CSES brings the productivity features you expect from a modern coding environment while preserving everything you already like about CSES. Most importantly, it doesn't replace CSES—it enhances it. • Your account remains your CSES account. • Your submissions still go through CSES. • Disable the extension at any time and the original website is instantly restored. ──────────────────────────────────────── Features Modern Split-Pane Workspace Practice with a clean, resizable layout that keeps the problem statement and your code editor side by side for a faster, more focused workflow. Monaco Editor Write code using the same editor engine that powers Visual Studio Code. Features include: • Syntax highlighting • Smart indentation • Bracket matching • Multiple cursors • Professional editing experience Automatic Code Saving Never lose progress again. Every solution is automatically saved locally for each problem and programming language, allowing you to continue exactly where you left off. Multi-Language Support Starter templates are included for: • C++ • C • Python • Java Run Test Cases (New in v1.1.1) Run your code directly inside the workspace using both the official sample inputs and your own custom test cases. Quickly verify your solution before submitting without leaving the problem page. Custom Test Cases Create, edit, and organize your own test cases for every problem. Your custom inputs are saved locally and remain available whenever you return. Seamless Theme Support Automatically follows CSES's light and dark theme, so there's no separate theme setting to manage. Native CSES Submission Leetify for CSES never replaces CSES's submission system. Your code is transferred into CSES's own submission form, and the final submission is still performed through CSES itself. Local-First Privacy Everything stays on your computer. Your code, custom test cases, and settings are stored locally using Chrome's storage APIs. • No analytics • No tracking • No advertising • No external servers ──────────────────────────────────────── Workflow 1. Open any problem on cses.fi. 2. Log in to your CSES account to run and submit solutions. 3. The workspace loads automatically. 4. Write your solution in the Monaco Editor. 5. Your code is saved automatically as you type. 6. Run your solution against sample or custom test cases. 7. Submit using CSES's native submission workflow. 8. Return later and continue exactly where you left off. ──────────────────────────────────────── Who Is It For? Leetify for CSES is built for: • Competitive programmers • ICPC participants • IOI students • Codeforces users • LeetCode users • College students • Software engineers preparing for coding interviews • Anyone solving problems on the CSES Problem Set ──────────────────────────────────────── Frequently Asked Questions Does this replace CSES? No. It enhances the existing CSES website while preserving its native functionality. Accounts, submissions, and judging remain entirely on CSES. Does it run or judge my code? Yes. Starting with version 1.1.1, you can run your code against sample and custom test cases directly within the workspace. Final judging and submissions are still handled by CSES's official online judge. Do I need another account? No. The extension requires no registration or sign-up. Simply use your existing CSES account. Is my code uploaded anywhere? No. Your code, custom test cases, and preferences remain stored locally in your browser. The extension does not upload your work to any third-party server. Which websites are supported? Currently, Leetify for CSES is designed exclusively for cses.fi. ──────────────────────────────────────── Practice Smarter on CSES Whether you're preparing for ICPC, improving your algorithmic problem-solving skills, or getting ready for technical interviews, Leetify for CSES gives you the modern coding environment that CSES has always deserved. Install Leetify for CSES and transform your CSES experience with a faster, cleaner, and more productive workflow.