AlgoReps

Stop grinding. Start retaining.
A spaced repetition platform for mastering Data Structures & Algorithms.

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The Problem

You solve 200+ LeetCode problems. Two weeks later, you blank on a medium-difficulty question in an interview. Sound familiar?

The issue isn't practice volume -- it's the forgetting curve. Without systematic review, retention drops exponentially within days.

The Solution

AlgoReps applies spaced repetition (the same science behind Anki and language-learning apps) to DSA practice. An SM-2 variant algorithm schedules reviews at optimal intervals based on how well you performed, so you revisit problems right before you'd forget them.

Struggled? You'll see it again tomorrow. Nailed it? See you in two weeks.

Features

Spaced Repetition Engine

SM-2 variant scheduling based on self-assessed performance scores (1-5). The algorithm calculates optimal review intervals to maximize retention with minimal reviews.

Built-in Code Editor

Monaco-powered editor with Python 3 and Go support. Write, run, and test your solutions directly in the browser with a 10-second execution timeout and stdout/stderr capture.

AI Code Review (Optional)

Gemini 2.5 Flash integration that analyzes your solution for:

• Time and space complexity
• Code quality and readability
• Edge case coverage
• Alternative approaches
• Interview readiness score

Live Attempt Timer

Built-in stopwatch that starts when you begin a problem and tracks elapsed time throughout your attempt. Time spent is automatically logged with each submission, helping you build interview-pace awareness and identify problems that take longer than expected.

Trust Mode Logger

Solved a problem on LeetCode, CodeChef, Codeforces, HackerRank, GeeksforGeeks, or in a notebook? Log it without submitting code. Add the problem URL, your approach, and remarks -- it still gets scheduled for review.

Progress Dashboard

• Total problems solved, current streak, average score
• Topic mastery chart (Recharts)
• Full submission history with sorting and filtering
• Due today / due this week counters

Problem Bank

300+ curated problems from NeetCode-150 and Blind-75, each with:

• Full description, examples, and constraints
• Python 3 and Go code stubs
• Hints and NeetCode video links
• Difficulty and topic tags

Discord Notifications

• Morning briefing (8:00 AM): Lists all due revisions grouped by difficulty
• Evening wrap-up (9:00 PM): Daily stats, streak, and weak topics

Multi-Platform Support

Add problems from any major competitive programming site -- LeetCode, CodeChef, Codeforces, HackerRank, and GeeksforGeeks. The platform is auto-detected from the URL, and problem titles are auto-filled from the slug.

CSV Import

Bulk import problems from Google Sheets exports with automatic deduplication by slug. Supports both problem_url and leetcode_url columns.

Theme System

Dark, light, and system modes with a neon hacker aesthetic (cyan/green/purple glow effects).

Tech Stack

Getting Started

Prerequisites

• Node.js 18+
• Python 3 (for code execution)
• Go (for code execution)
• A Supabase project (free tier works)
• A Google AI Studio API key (optional, for AI review)

1. Clone and install

git clone https://github.com/the-mrinal/algoreps.git
cd algoreps
npm install

2. Configure environment

cp .env.local.example .env.local

Fill in your keys:

# Required
NEXT_PUBLIC_SUPABASE_URL=https://your-project.supabase.co
NEXT_PUBLIC_SUPABASE_ANON_KEY=your-anon-key
SUPABASE_SERVICE_ROLE_KEY=your-service-role-key

# Optional -- AI code review
GEMINI_API_KEY=your-gemini-api-key

# Optional -- Discord notifications
DISCORD_WEBHOOK_URL=https://discord.com/api/webhooks/...
CRON_SECRET=your-random-secret

3. Set up the database

Run the schema file in your Supabase SQL Editor:

# Copy the contents of supabase/schema.sql and run it in the
# Supabase Dashboard → SQL Editor

This creates:

• profiles -- auto-created on signup via database trigger
• problems -- problem bank with full metadata
• user_progress -- submissions, SRS state, AI reviews
• Row-Level Security policies for all tables

4. Seed the problem bank

npx tsx scripts/seed-problems.ts

This loads 300+ curated problems from data/problems.json into your Supabase instance.

5. Start the dev server

npm run dev

Open http://localhost:3000.

Project Structure

src/
├── app/
│   ├── page.tsx                     # Landing page
│   ├── login/                       # Magic link auth
│   ├── auth/callback/               # OAuth callback handler
│   ├── dashboard/
│   │   ├── page.tsx                 # SRS revision queue
│   │   ├── practice/                # Code editor + problem browser
│   │   ├── log/                     # Trust mode submission form
│   │   ├── progress/                # Stats, charts, history
│   │   └── import/                  # CSV problem import
│   └── api/
│       ├── run-code/                # Python 3 / Go code execution
│       ├── analyze/                 # Gemini AI code review
│       ├── submissions/             # CRUD for user_progress
│       ├── problems/                # Problem CRUD
│       └── cron/                    # Morning & evening notification jobs
├── components/                      # UI components organized by feature
│   ├── srs/                         # RevisionQueue, RevisionCard
│   ├── practice/                    # EditorPane, ProblemPane, AIReview
│   ├── progress/                    # StatsOverview, TopicChart, HistoryTable
│   ├── logger/                      # TrustModeForm
│   ├── import/                      # SheetImportForm
│   ├── dashboard/                   # Sidebar, DesktopOnly
│   └── theme/                       # ThemeProvider, ThemeToggle
├── lib/
│   ├── supabase/                    # Browser, server, and admin clients
│   ├── srs.ts                       # SM-2 variant algorithm
│   ├── url-parser.ts                # Multi-platform URL parser
│   ├── ai-review.ts                 # Gemini prompt builder
│   ├── discord.ts                   # Discord webhook sender
│   └── problems.ts                  # Problem query helpers
├── contexts/                        # React contexts (user/premium state)
└── types/                           # Shared TypeScript interfaces

scripts/                             # Seed, deploy, and cron scripts
data/                                # Problem bank JSON + solution templates
supabase/                            # Schema SQL + migrations

Database Schema

profiles

Extends Supabase Auth. Auto-created via trigger on signup.

user_progress

Tracks every submission and its SRS state.

problems

The problem bank. Publicly readable by authenticated users.

All tables are protected by Row-Level Security -- users can only access their own data.

API Endpoints

Cron endpoints are protected by a CRON_SECRET header.

Deployment

See DEPLOYMENT.md for full production setup instructions covering:

• DigitalOcean droplet provisioning
• PM2 process management
• Nginx reverse proxy configuration
• Let's Encrypt SSL certificates
• Crontab setup for notifications

Scripts

npm run dev                          # Start dev server (port 3000)
npm run build                        # Production build
npm start                            # Start production server
npm run lint                         # Run ESLint
npx tsx scripts/seed-problems.ts     # Seed problem bank into Supabase
npx tsx scripts/merge-problems.ts    # Rebuild problem bank from sources

Contributing

Contributions are welcome! Here's how to get started:

1. Fork the repository
2. Create a feature branch (git checkout -b feat/your-feature)
3. Make your changes
4. Run lint checks (npm run lint)
5. Commit your changes (git commit -m 'feat: add your feature')
6. Push to your branch (git push origin feat/your-feature)
7. Open a Pull Request

Please follow the existing code style and conventions.

Roadmap

• Multi-language support (Java, C++, JavaScript)
• Collaborative problem sets
• Streak calendar visualization
• Mobile app
• Custom SRS intervals
• Public problem set sharing

License

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

Acknowledgments

• Problem bank sourced from NeetCode and Blind 75
• Spaced repetition algorithm based on SM-2
• Built with Next.js, Supabase, and Monaco Editor