Masum Galaxy // CP Arena

A focused, futuristic Competitive Programming cockpit for VS Code: local judging, contest tracking, stress testing, verdict diagnostics, benchmarks, snippets, safe AI coaching, and keyboard-first workflows.

Standalone edition of the CP Arena experience. The original CP Arena inside Masum Galaxy // Developer OS remains unchanged.

Highlights

• Contest timer with A–H problem tracking, per-problem state, attempts, and solving time
• Local sample judge for C/C++, Python, and JavaScript
• Dedicated multi-case judge using --- separators
• First-mismatch Verdict Diff Viewer for Wrong Answer debugging
• Runtime and best-effort peak-memory benchmark display
• Stress testing with Generator + Brute + Optimized solutions
• Saved failing stress input with Re-run Failed Case
• C++17 / Python / JavaScript problem templates
• Competitive-programming Snippet Vault
• CP Focus mode using VS Code Zen Mode
• Verdict and stress-test history
• AI Complexity analysis, Edge Case generation, and Panic Assist
• Quick access to Codeforces, AtCoder, LeetCode, and CodeChef
• Keyboard-first shortcuts for common contest actions

Supported runners

On Windows, CP Arena also checks common MSYS2/MinGW compiler locations such as C:\msys64\ucrt64\bin. Normal sample and multi-case executions use a 5-second limit. C/C++ builds use C17/C++17 with -O2.

Open the Arena

Click Galaxy CP Arena in the Activity Bar, or run:

Masum Galaxy CP Arena: Open Arena

The Command Palette also exposes contest, problem-file, stress-test, snippet, focus, re-run, AC, and navigation commands.

Keyboard shortcuts

Multi-case judge

Put each case in the dedicated Multi-case Input box and separate cases with a line containing only:

---

Do the same in Multi-case Expected Output. Input and expected-output case counts must match.

Example input:

1 2
---
5 7
---
10 20

Expected:

3
---
12
---
30

Verdict diagnostics

When expected and actual output differ, CP Arena reports the first mismatching token and line and shows the corresponding expected/actual values. Run results also show runtime and a best-effort peak-memory sample when the process lives long enough to be measured.

Stress testing

1. Open the optimized solution.
2. Choose Stress Test.
3. Select the generator.
4. Select the brute-force solution.
5. Choose 1–100 iterations.

The Arena stops on the first mismatch or failed stage, stores the failing input/results, and exposes Re-run Failed Case so the optimized solution can be reproduced against that exact input.

New Problem File and Snippet Vault

New Problem File creates a C++17, Python, or JavaScript starter. If no workspace root is available, CP Arena falls back to the active source folder or asks you to choose a folder.

Snippet Vault inserts CP-focused snippets directly at the current editor selection/cursor.

AI Coach

AI actions use the VS Code Language Model API. CP Arena prefers models exposed by the GitHub Copilot provider and falls back to other compatible VS Code language-model providers when available.

• O() Complexity analyzes selected code, or the current source file.
• Edge Cases designs high-value tests without inventing an unseen input format.
• Panic Assist reads a copied problem statement and returns three escalating hints instead of a copy-paste final solution.

AI features only run after an explicit user action.

Privacy and safety

• Contest state and run history stay in this extension's VS Code storage.
• Local judging executes source files on the user's own environment.
• No hard-coded personal project path, GitHub token, or API key is included.
• AI actions may send the selected/current code or copied problem statement to the VS Code language-model provider only after the user invokes the action.
• Untrusted workspaces are not supported because CP Arena can compile and execute workspace code.

Development

npm install
npm run check
npm test
npm run package

Press F5 to launch an Extension Development Host.

Banner replacement

The current README banner is intentionally replaceable. Later, put your preferred PNG at:

media/cp-arena-banner.png

Keep that filename and the README banner will update automatically.

Support

See SUPPORT.md or open an issue in this repository.

Origin

The CP engine was extracted from Masum Galaxy // Developer OS so it can also exist as a focused standalone extension. The Developer OS copy remains in place.

License

MIT © 2026 Masum Billah