LeetCore — DSA Practice Platform with Real-Time C++ Code Execution

Master Data Structures & Algorithms with a Structured Roadmap, Built-In IDE, and a High-Performance C++ Execution Engine

LeetCore is an open-source DSA (Data Structures and Algorithms) learning and practice platform built for developers preparing for coding interviews, competitive programming, and placement exams. It combines a structured DSA roadmap, an in-browser coding IDE with Monaco Editor, a real-time C++ code execution engine, and progress analytics — all in one full-stack application.

Getting Started • Features • Tech Stack • Architecture • Roadmap • Contributing

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📌 Why LeetCore?

If you're searching for a free open-source LeetCode alternative, a DSA practice tool with a built-in code compiler, or a project to learn full-stack system design (React + Node.js + C++), LeetCore is built exactly for that use case. It's ideal for:

• Students preparing for technical coding interviews at product-based companies
• Developers who want a self-hosted DSA tracker with real code execution
• Engineers learning how to build a custom online judge / code execution engine
• Anyone contributing to an open-source educational coding platform

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🖥️ System Architecture

React (Frontend UI)
        ↓
Node.js (API Layer / Controller)
        ↓
C++ Engine (Execution & DSA Logic)

Key Responsibilities

Layer	Responsibility
Frontend (React)	User interface, in-browser IDE, algorithm visualization, dashboard & roadmap
Backend (Node.js)	REST API handling, request validation, routing code to the execution engine
C++ Engine	Code compilation, sandboxed execution, performance-critical DSA logic

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⚙️ Tech Stack

Category	Technology
Frontend	React.js, Tailwind CSS, React Router
Backend	Node.js, Express.js
Execution Engine	C++, g++ compiler
Editor	Monaco Editor (VS Code engine)
Utilities	Nodemon, Axios

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📁 Project Structure

leetcore/
│
├── client/        # React frontend — IDE, dashboard, roadmap UI
├── server/        # Node.js backend — API layer & controllers
├── cpp-engine/    # C++ execution engine — compiles & runs user code
│
├── docs/          # DSA documentation (coming soon)
└── README.md

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✨ Features

📚 Structured Learning System

• Curated, topic-wise DSA roadmap
• Pattern-based problem categorization (two-pointers, sliding window, DP, graphs, etc.)
• Beginner-to-advanced learning path

💻 Built-In Coding IDE

• Syntax-highlighted code editor (Monaco Editor)
• Custom input/output console
• Real-time code execution feedback

⚡ Real-Time C++ Execution Engine

• Executes user-submitted code via a native C++ compilation pipeline
• Fast, lightweight, and efficient runtime handling
• Supports custom test-case inputs

📊 Progress Tracking & Analytics

• Track solved problems by topic and difficulty
• Visual completion status across the roadmap
• Performance insights over time

🎬 Algorithm Visualization (Upcoming)

• Step-by-step execution visualization
• Interactive flow for recursion, sorting, and graph traversal

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🔄 Code Execution Flow

User writes code (React IDE)
        ↓
API request → /run-code
        ↓
Node.js backend validates & forwards request
        ↓
C++ engine compiles & executes the code
        ↓
Output/errors returned to the frontend console

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🚀 Getting Started

Prerequisites

• Node.js (v16+ recommended)
• g++ compiler installed and available in your system PATH
• Git

1. Clone the Repository

git clone https://github.com/MOHITGODARA1/leetcore.git
cd leetcore

2. Set Up the Frontend

cd client
npm install
npm run dev

3. Set Up the Backend

cd server
npm install
npm run dev

4. Set Up the C++ Execution Engine

Verify g++ is installed:

g++ --version

Compile the engine:

cd cpp-engine
g++ main.cpp -o engine

Once all three services are running, open the frontend URL shown in your terminal (typically http://localhost:5173) to start using LeetCore.

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🗺️ Future Improvements

• Docker-based secure & sandboxed code execution
• Multi-language support (Python, Java, JavaScript)
• AI-based problem recommendation engine
• Advanced analytics dashboard
• Real-time collaborative coding rooms

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🎯 Project Goals

• Build strong DSA fundamentals through structured practice
• Provide an all-in-one, self-hosted coding interview prep platform
• Simulate real technical interview environments
• Demonstrate a scalable, full-stack system design (React + Node.js + C++)

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🤝 Contributing

Contributions are what make the open-source community thrive. Any contributions you make are greatly appreciated.

1. Fork the repository
2. Create your feature branch (git checkout -b feature/AmazingFeature)
3. Commit your changes (git commit -m 'Add some AmazingFeature')
4. Push to the branch (git push origin feature/AmazingFeature)
5. Open a Pull Request

Please open an issue first for major changes to discuss what you'd like to modify.

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📄 License

This project is licensed under the MIT License — see the LICENSE file for details.

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🙏 Acknowledgment

Inspired by modern coding practice platforms and built to provide a more structured, transparent, and open DSA learning experience.

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👤 Author

Mohit Godara Full Stack Developer | Problem Solver

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⭐ If you find LeetCore useful, consider giving it a star — it helps others discover the project!

Keywords: DSA practice platform, LeetCode alternative, coding interview prep, online code compiler, C++ execution engine, React Node.js full-stack project, algorithm visualization, competitive programming tool, open-source coding platform