• 6 Comprehensive Topics: Arrays, Strings, Linked Lists, Trees, Graphs, Dynamic Programming
• Each topic includes:
  • Detailed theory explanations
  • Key concepts and properties
  • Common problem patterns
  • Difficulty ratings (Easy-Medium-Hard)
  • Sample problem lists

• 15+ curated problems spanning all DSA topics
• Filterable by difficulty (Easy, Medium, Hard)
• Real-time search functionality
• Problem tags for quick identification
• Acceptance rate tracking
• Visual completion badges

Users can now:

• Mark practice problems as favorites
• Filter favorite problems
• Persist favorites using localStorage

How it works:

• Click the heart icon on any practice problem
• Use the "Favorites" filter to view saved problems

60 Topic-Specific Questions (10 per topic covering key concepts)

• Arrays: Time complexity, operations, Two Sum, Kadane's algorithm, rotation techniques
• Strings: Pattern matching (KMP), palindrome detection, anagrams, sliding window
• Linked Lists: Pointer manipulation, cycle detection, reversal, merging
• Trees: Traversals, BST properties, height calculation, LCA, heaps
• Graphs: Representations, BFS/DFS, topological sort, Dijkstra, MST algorithms
• Dynamic Programming: Memoization, tabulation, classic problems (Fibonacci, Knapsack, LIS, Edit Distance)

Quiz Features:

• Interactive modal interface
• Progress bar tracking
• Instant answer feedback (correct/incorrect highlighting)
• Detailed explanations for each question
• Score calculation (percentage)
• XP rewards: 10 XP per correct answer
• Best score tracking per topic
• Attempt counter
• Randomized question order

Flow

1. User clicks "Start Quiz" on topic card
2. Questions are shuffled randomly
3. Modal displays one question at a time
4. User selects an answer → immediate feedback
5. Correct answer highlighted in green; user's wrong choice in red
6. Auto-advance after 1.2 second delay
7. After 10 questions: score calculation
8. Results modal shows percentage, XP earned, performance message
9. Progress bars and statistics update

Scoring

• 10 XP per correct answer
• Best score saved per topic (max percentage)
• Total attempts tracked
• Progress bar fills on first attempt

Customizable Profile:

• Edit display name
• Choose from 12 avatar emojis
• View join date
• Track level progression

Progress Tracking:

• Total XP accumulation
• Problems solved counter
• Day streak monitoring
• Badge earning system

Levels:

• 8 levels from Beginner to Legend
• XP thresholds: 0, 1,000, 2,500, 5,000, 10,000, 20,000, 50,000, 100,000
• Automatic level-up notifications

Badges:

• 🌟 First Steps (solve 1 problem)
• 🔥 On Fire (7-day streak)
• 💎 Diamond (5,000 XP)
• 🚀 Rocket (50 problems)
• 👑 Master (100 problems)
• 🎯 Sharpshooter (25 problems + 2,500 XP)

Badge tooltips: Hover or tap any badge on the dashboard to see the badge name, description, and unlock criteria.

• Complete statistics overview
• Recent activity feed
• Achievement badges display
• Leaderboard comparison
• Roadmap progress visualization

• Secure signup and login pages
• PBKDF2 password hashing with per-user salts and a server-side pepper for enhanced password security
• Signed JWT-style sessions stored in HTTP-only cookies
• Logout endpoint that clears the session cookie
• Protected community and support pages
• Dashboard/profile hash routes redirected to login when unauthenticated

• Multi-language support (JavaScript, Python, Java, C++)
• Line numbers and syntax highlighting
• Code snippets insertion
• Auto-formatting
• Line comment toggling
• Run and submit simulation
• Test case validation

• Instant DSA concept explanations
• Time/space complexity queries
• Problem-solving strategy hints
• Quick question buttons
• Context-aware responses

Visual Design:

• Dark/Light theme toggle
• Glassmorphism UI elements
• Gradient accents
• Animated transitions
• Starfield background effect
• Responsive layout (mobile, tablet, desktop)

Navigation:

• Sticky navbar with smooth scrolling
• Mobile hamburger menu
• Scroll-to-top button
• Section-based navigation

• HTML5: Semantic markup
• CSS3: Custom properties, Flexbox, Grid, animations
• JavaScript (ES6+): Vanilla JS, no frameworks
• Node.js: Local HTTP server and authentication APIs
• Node Crypto: Password hashing and signed session tokens
• LocalStorage: Persistent user data
• Font Awesome: Icon library
• Google Fonts: Orbitron, Poppins, Fira Code

• Modern web browser (Chrome, Firefox, Safari, Edge)
• Node.js 18+ for authentication

1. Clone the repository

   git clone https://github.com/yourusername/Algo-Infinity-Verse.git
   cd Algo-Infinity-Verse

2. Start the authenticated app Create your local environment file:

   cp .env.example .env

   Generate secure secrets for your environment:

   node -e "console.log('SESSION_SECRET=' + require('crypto').randomBytes(64).toString('hex')); console.log('PASSWORD_PEPPER=' + require('crypto').randomBytes(32).toString('hex'));"

   Copy the generated values into your .env file:

   SESSION_SECRET=your_generated_session_secret
   PASSWORD_PEPPER=your_generated_password_pepper

   Start the server:

   npm start

   Then visit http://127.0.0.1:3000

   You can still open index.html directly for static browsing, but signup, login, protected routes, and HTTP-only sessions require the Node server.

3. Start learning!

   • Create your profile
   • Browse DSA topics
   • Take quizzes
   • Practice problems
   • Track your progress

Algo-Infinity-Verse/
├── index.html          # Main HTML structure
├── login.html          # Login page
├── signup.html         # Registration page
├── server.js           # Static server and authentication API
├── auth.js             # Client-side auth UI and route guards
├── styles.css          # All CSS styles and responsive design
├── script.js           # JavaScript logic, data, and interactivity
└── README.md           # Project documentation

dsaTopics - Topic information including:

• ID, name, icon, description
• Difficulty level
• Theory explanation
• Related problems

quizQuestions - Quiz database:

• 60 questions across 6 topics
• Multiple-choice format (4 options)
• Correct answer indices
• Detailed explanations

practiceProblems - Problem catalog:

• Title, difficulty, tags
• Acceptance rates
• Category associations

chatbotResponses - Knowledge base:

• DSA concept explanations
• Complexity definitions
• Algorithm overviews

userProgress object tracks:

• User name and avatar
• Completed problem IDs
• Total XP and current level
• Day streak count
• Earned badges
• Quiz scores per topic
• Last active date

Persisted to localStorage under key algoInfinityVerse.

Edit script.js and add to quizQuestions object:

const quizQuestions = {
    arrays: [
        {
            id: "arrays-11", // unique ID
            question: "Your question here?",
            options: ["Option A", "Option B", "Option C", "Option D"],
            correct: 0, // 0-indexed correct answer
            explanation: "Detailed explanation of why the answer is correct"
        },
        // ... more questions
    ],
    // ... other topics
};

1. Add to dsaTopics array with icon, description, theory
2. Add corresponding quizQuestions[topicKey] array with 10 questions
3. The UI auto-generates topic cards and quiz cards

Colors: Edit CSS variables in :root:

:root {
    --primary: #7c3aed;      /* Main purple */
    --secondary: #3b82f6;    /* Blue accent */
    --accent: #06b6d4;       /* Cyan highlight */
    /* ... */
}

Fonts: Update Google Fonts links in index.html and CSS font-family declarations.

XP Values: Modify getXPForDifficulty() function for practice problems or quiz XP calculation.

• Chrome 90+
• Firefox 88+
• Safari 14+
• Edge 90+

Uses modern ES6+ features and CSS Grid/Flexbox.

Potential features for expansion:

• Database backend for multi-user support
• Real code execution sandbox
• Social features (friends, groups, competitions)
• Advanced analytics and learning insights
• Video tutorials and explanations
• Mobile app (React Native)
• Interview simulation mode
• Company-specific question banks

We welcome contributions! Please see our Contributing Guide for details.

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

Be respectful and constructive. See our Code of Conduct for guidelines.

• 📧 Email: opensource@algo-infinity-verse.org
• 💬 Discord: Join our server
• 🐛 Report bugs via GitHub Issues

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

• Inspired by LeetCode, HackerRank, and freeCodeCamp
• Built with ❤️ for the DSA learning community
• Icons by Font Awesome
• Fonts by Google Fonts

Start your DSA journey today and level up your coding skills! 🚀