SimpleOJ is an interactive online platform for coding enthusiasts. It allows users to solve programming challenges and run code snippets in C, C++, Java, and Python.

You can use @ah_naf/runcode npm package to run C, C++, Python and Java code.

For a visual demonstration of SimpleOJ in action, check out our video demo.

• Authentication: Users can log in using Google authentication, powered by PassportJS.
• Problem Management: Authenticated users can add, edit, and delete programming problems, complete with custom test cases.
• Code Execution: All users can run their code on the problem page. Code submissions and verifications are available for signed-in users.
• Submission Feedback: After submitting code, users receive immediate feedback on whether their solution is accepted, incorrect, or has timed out (TLE).
• History: Users can view their past submissions for each problem and view their code.
• Status: Users can see everyones recent submissions.

SimpleOJ uses Node.js child processes to execute C, C++, Java and Python code. The execution is managed in the backend, ensuring secure and isolated runtime environments for each code snippet.

• Frontend: Developed with ReactJS for a dynamic user interface.
• Backend: Built on NodeJS with Express, offering a robust server-side framework.
• Database: MongoDB is used for data storage, providing flexibility and scalability.
• Authentication: PassportJS manages user authentication, ensuring secure logins.
• Concurrency Management: Bull Queue is utilized to handle concurrent code execution requests efficiently.
• Containerization: Docker is used for containerizing the application, ensuring a consistent environment across different machines.

• Complexity Analysis: I aim to incorporate memory complexity analysis for running code. Resources and learning are underway for this implementation.

To get SimpleOJ up and running on your local machine, follow these instructions:

• Ensure Docker is installed on your machine.
• Node.js and npm should be installed for managing dependencies.

1. Install Docker: If you haven't already, install Docker following the instructions here.

2. Clone Repository: Clone this repository to your local machine using git clone [repository-url].

3. Install Dependencies:

   • Navigate to the client directory in the terminal and run npm install to install all client-side dependencies.
   • Similarly, go to the server directory and run npm install for server-side dependencies.

4. Set Up Environment Variables:

   • In the server directory, create a .env file.
   • Add the following environment variables:

     GOOGLE_CLIENT_ID=your_google_client_id
     GOOGLE_CLIENT_SECRET=your_google_client_secret
     

     Replace your_google_client_id and your_google_client_secret with your actual Google client ID and secret.

5. Start the Application:

   • From the root directory of the project, run docker compose up in the terminal. This will set up the necessary Docker containers.
   • Optionally, you can run the client and server separately by navigating to their respective directories and executing npm start in each.

6. Accessing SimpleOJ:

   • Once everything is up and running, your local instance of SimpleOJ should be accessible. The client will typically run on http://localhost:3000, and the server will run on http://localhost:5000.

• If you encounter any issues during the setup, ensure all the environment variables are correctly set and that Docker is running properly.
• For any dependency-related issues, try removing the node_modules folder in the client and server directories, and run npm install again. gi

For any assistance or inquiries, feel free to connect with me on LinkedIn.