🎉 Codespaces

I was curious about how Codeforces worked, so created my own version! Welcome to Codespaces—your social problem solving playground! 🧑‍💻✨

✨ Features

• ✏️ Create Your Own Problems: Feeling creative? You can also create and manage your own coding problems! 🎨

• 🔍 Codeforces Problem Scraping: Users can just enter a Codeforces problem link and watch the magic happen! The problem statement and test cases are automatically parsed and shared across all the users int the room. 🌟

• 🚀 Code Evaluation: Evaluate code submissions on the fly!

• 👩👨‍💻 Collaborative Coding: Team up with your friends and solve problems together in real-time with up to 10 users.

• 🎤 Group Voice Chat: Integrated group voice chat for seamless collaboration using WebRTC.

• 📦 Problem Packages: Easily store and manage problem packages.

• 🧮🖼️ Math and Image Rendering: Supports rendering math equations and images (or any media) in problem statements.

• ⚡ Caching: Lightning-fast caching for problem statements and packages using Redis.

Can be used to host contests completely locally(for the most part)

🎬 Demo

Check out the demo here. 🍿

Hosting is down at the moment cause I lost access to my EC2 instance :(

🏗️ System Architecture

Here's a high-level architecture of our cute little system. 🥰

📝 Submission Handling

• Every new submission triggers a new Docker container (Alpine Linux). 🐳
• The container:
  • Compiles and runs the program.
  • Pulls the test data from the database if it’s not cached.
  • Compares the program output to the expected output.
  • Sends a verdict (AC/WA/CR/TLE/RTE).
• Programs have a 2-second time limit; if they don't finish in time, they get a TLE (Time Limit Exceeded) verdict. ⏰

🔧 Implementation Details

• 🎤 Group Voice Chat: Implemented using WebRTC to reduce server load. Chat with your whole group while you code!

• 🐳 Docker API: Used to spawn containers on the fly for code evaluation.

• 🤝 Collaborative Features: Utilized WebSockets (Socket.IO) for real-time collaboration.

• ⛏ Web scraping: Used BeautifulSoup with a custom scraper to scrape problems from codeforces.

• 📦 Problem Packages: Stored in MongoDB for easy management.

  • Includes:
    • Problem Statements (Interpreted)
    • Sample test data
    • Main test data (for evaluating submissions)
    • Expected outputs for the main tests

• ⚡ Redis Caching: Cached problem packages and test data to limit database hits.

• 🧮 Math Rendering: Used KaTeX for rendering math equations.

• 🚫 Rate Limiting: Added to each compilation API call to prevent abuse.

🌐 Supported Languages

• Only supports C++ for now. 🖋️

🚀 Usage

To use this project, follow these steps:

1. Clone the repository:

   git clone https://github.com/nubskr/codespace.git
   cd codespace

2. Install dependencies:

   npm install

3. Start the server:

   npm start

4. Open the application in your browser.

Prerequisites

• You need Docker and Redis installed in the backend to use the submission functionality.
• The ./Docker directory contains the Docker image I made to evaluate the submissions.