⚡ QuizEngine

An Intelligent Algorithm-Driven Quiz Platform

Adaptive Learning • Real-Time Scoring • Graph-Based Progression

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📁 Project Structure

quizengine/
├── backend/
│   ├── algorithms/
│   │   ├── shuffle.js       ← Fisher–Yates shuffle
│   │   ├── scoring.js       ← Greedy streak scoring engine
│   │   ├── sorting.js       ← Leaderboard & difficulty sort
│   │   └── graph.js         ← Topological sort, unlock logic
│   ├── config/
│   │   └── db.js            ← MongoDB connection
│   ├── controllers/
│   │   ├── authController.js
│   │   ├── quizController.js
│   │   ├── topicController.js
│   │   ├── questionController.js
│   │   └── leaderboardController.js
│   ├── data/
│   │   └── seed.js          ← Seed script (6 topics, 30 questions)
│   ├── middleware/
│   │   └── auth.js          ← JWT protect + admin middleware
│   ├── models/
│   │   ├── User.js
│   │   ├── Topic.js         ← Graph nodes
│   │   ├── Question.js
│   │   └── QuizAttempt.js
│   ├── routes/
│   │   ├── auth.js
│   │   ├── quiz.js
│   │   ├── topics.js
│   │   ├── questions.js
│   │   ├── leaderboard.js
│   │   └── users.js
│   ├── server.js
│   ├── Dockerfile
│   └── package.json
│
├── frontend/
│   ├── public/index.html
│   ├── src/
│   │   ├── components/
│   │   │   ├── Graph/
│   │   │   │   ├── TopicGraph.jsx   ← Interactive SVG graph
│   │   │   │   └── TopicCard.jsx
│   │   │   └── UI/
│   │   │       ├── Navbar.jsx
│   │   │       └── Navbar.module.css
│   │   ├── context/
│   │   │   └── AuthContext.jsx      ← Global auth state
│   │   ├── pages/
│   │   │   ├── HomePage.jsx
│   │   │   ├── LoginPage.jsx
│   │   │   ├── RegisterPage.jsx
│   │   │   ├── TopicsPage.jsx
│   │   │   ├── QuizPage.jsx         ← Main quiz experience
│   │   │   ├── ResultsPage.jsx
│   │   │   ├── LeaderboardPage.jsx
│   │   │   └── HistoryPage.jsx
│   │   ├── styles/
│   │   │   └── global.css           ← Design system tokens
│   │   ├── utils/
│   │   │   ├── api.js               ← Axios instance
│   │   │   └── algorithms.js        ← Client-side algorithm mirrors
│   │   ├── App.jsx
│   │   └── index.jsx
│   ├── Dockerfile
│   ├── nginx.conf
│   └── package.json
│
├── docker-compose.yml
└── README.md

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🚀 Overview

QuizEngine is a full-stack, algorithm-powered quiz platform designed to deliver a smart, adaptive, and engaging learning experience.

It combines:

• 🧠 Data Structures & Algorithms
• ⚡ Real-time interaction
• 🌐 Modern full-stack architecture

to create a production-ready intelligent learning system.

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✨ Key Highlights

• ⚡ Algorithm-driven quiz logic
• 🔗 Graph-based topic unlocking (DAG)
• 📊 Real-time leaderboard system
• 🔐 Secure authentication (JWT)
• 🐳 Docker-ready deployment

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🧠 Core Features

🧠 Smart Algorithms

• Fisher–Yates Shuffle (O(n), unbiased randomization)
• Greedy scoring with streak bonuses
• DAG-based topic progression (Topological Sort)
• Multi-condition sorting system

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🎮 Interactive Experience

• Real-time quiz interface
• Countdown timer + progress tracking
• Smooth UI transitions
• Dark/Light mode support
• Fully responsive design

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🔐 Security & Authentication

• JWT-based authentication system
• Protected routes & middleware
• Admin-controlled data operations

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📊 Analytics & Performance

• Dynamic leaderboard ranking
• Quiz history tracking
• Score visualization
• Performance-based topic unlocking

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🏗️ System Architecture

graph TD
A[React Frontend] --> B[API Layer]
B --> C[Node.js Backend]
C --> D[MongoDB Database]

Loading

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🧠 Algorithm Engine (Core Strength)

🔀 Fisher–Yates Shuffle

Ensures true randomness in quiz sessions with O(n) complexity.

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⚡ Greedy Scoring Logic

• +5 → Correct

• −1 → Incorrect (min = 0)

• 🔥 Streak bonuses:

  • 3 correct → +2
  • 5 correct → +5

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🔗 Topological Sort (DAG)

• Topic unlocking based on prerequisites
• Ensures structured learning progression
• Implemented using Kahn’s Algorithm

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📊 Advanced Sorting

• Leaderboard → score desc + name tie-break
• Questions → difficulty-based ordering
• Multi-field comparator system

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🏗️ Learning Path Graph

HTML → CSS → JavaScript → React
                     ↘
                      Node.js → Full Stack

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📸 Screenshots

📸 Application Preview

🌐 Live Demo

👉 https://your-app-link

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⚙️ Installation Guide

🔹 Backend Setup

cd backend
cp .env.example .env
npm install
npm run seed
npm run dev

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🔹 Frontend Setup

cd frontend
npm install
npm start

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🐳 Docker Deployment

docker-compose up --build
docker-compose exec backend node data/seed.js

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💡 Why This Project?

✔ Combines DSA + Full Stack Development ✔ Demonstrates real-world system design ✔ Implements scalable architecture ✔ Showcases problem-solving + engineering thinking

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🚀 Future Enhancements

• 🤖 AI-based adaptive difficulty
• 🌐 Multiplayer quiz system
• ⚡ WebSocket real-time updates
• 📊 Advanced analytics dashboard
• 📱 Mobile app version

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👨‍💻 Author

Rahul Raj Jaiswal 💼 LinkedIn: https://www.linkedin.com/in/rahulrajjaiswal/

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📄 License

This project is licensed under the MIT License.