ForgeSolve

A tool to discover, filter, and practice competitive programming problems with real-time Codeforces tracking.

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🚀 Live Demo

✨ Try ForgeSolve Now

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✨ Key Features

🔎 Problem Discovery & Filtering

• Multi-Platform: Codeforces, LeetCode, GeeksforGeeks
• Smart Filters: Rating range, difficulty levels, tags
• Problem Pool: 10K+ problems across platforms
• Smart Mode: Auto-adjust difficulty based on last solved problem rating
• Tag Search: Filter by algorithm/data structure tags

👥 Collaborative Features (Codeforces Only)

• Friend Filtering: Filter problems by what friends have solved/attempted
  • Friends' Solved: Only show problems your friends completed
  • Friends' Unsolved: Target problems your friends tried but couldn't solve
  • Any Problem: No friend-based restrictions
• Add up to 10 friends: Validate Codeforces handles and track their progress
• Per-Problem Stats: See how many friends solved each problem

⏱️ Submission Tracking

• Real-Time Detection: Automatically detect accepted Codeforces submissions
• Built-In Timer: Auto-starts when problem is picked, stops on AC verdict
• Streak System: Track consecutive days of solved problems
• History Management: Keep record of all picked problems with timestamps

📈 Profile Stats & Analytics

• Rich Stats Dashboard: Solved/Attempted counts, AC rate, streaks, rating distribution, top tags, monthly activity
• Rank & Rating: Color-coded badges with current/max rating
• Profile Sync: One-click refresh to update stats from Codeforces

⚙️ Personalization

• Exclude Solved: Hide completed problems
• Review Mode: Practice only solved problems
• Local Storage: All preferences, history, and friends persisted

🎯 Usage Guide

Getting Started

1. Select a platform (Codeforces, LeetCode, or GeeksforGeeks)
2. Set difficulty range and add tags (optional)
3. Click "Pick Problem" to get a random match

Friend Features (Codeforces)

1. Open the "Friends" panel and enter Codeforces handles
2. Choose filter mode: "Any Problem", "Friends' Unsolved", or "Friends' Solved"
3. Get problems based on your friends' activity

Tracking Progress

• View history in the History Panel
• Enable "Exclude Solved" to hide completed problems
• Check your Streak Badge for consecutive days solved

💻 Tech Stack

Frontend

• React 18 (Vite) — Fast build tooling & HMR
• Tailwind CSS 4 — Utility-first styling
• Lucide React — Lightweight SVG icons
• Axios — Promise-based HTTP client

Backend

• Node.js + Express 4 — Fast, lightweight REST API
• Codeforces API — Problem data, user submissions, ratings
• LeetCode & GeeksforGeeks APIs — Problem data
• Node Cache — In-memory caching (5-10 min TTL)
• Express Rate Limit — API protection (30 req/min)
• Axios — API calls with timeouts

Data & Storage

• Problem Dataset: 10K+ problems across 3 platforms
• Caching: Problem list (10 min), user stats (10 min)
• Client Storage: localStorage for history, filters, friends
• No Database: Everything computed on-the-fly from APIs

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📋 Roadmap

• User authentication and cloud storage for cross-device sync
• Problem recommendation engine based on solving history and weak tags
• LeetCode and GeeksforGeeks real-time submission tracking (currently Codeforces only)
• Timed contest mode with leaderboards
• Mobile application (iOS/Android)

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🏗️ Architecture

System Design

┌─────────────────┐         ┌──────────────────┐         ┌─────────────────┐
│                 │         │                  │         │                 │
│  Frontend       │◄────────►│  Backend API     │◄────────►│ Codeforces API  │
│  (React/Vite)   │ HTTPS    │  (Express)       │ HTTP    │  + LeetCode     │
│                 │         │                  │         │  + GeeksforGeeks│
└─────────────────┘         └──────────────────┘         └─────────────────┘
  (Vercel)                     (Render)

Design Principles

• Stateless Backend: Express API runs on Render with auto-scaling — no server sessions
• Client-Side State: All user data stored in localStorage for offline access
• Multi-Criteria Filtering: O(n) filter engine (rating, tags, history, friend status)
• Graceful Degradation: Promise.allSettled() handles partial failures in friend data collection
• Rate Limiting: 30 requests per minute per IP to prevent abuse
• Caching Strategy: 10-min TTL on problem lists and user stats; fresh friend data per request
• Parallel Processing: Concurrent API calls for user submissions and friend data
• Timeout Protection: 8-10 second timeouts on external API calls

Scaling Options

• Database Addition: Replace in-memory cache with Redis for distributed caching
• Friend Batch Processing: Queue long operations (10+ friends) asynchronously
• Problem Pre-computation: Periodically cache and pre-filter problem subsets
• CDN: Serve problem data from edge locations
• Horizontal Scaling: Deploy multiple backend instances behind load balancer

🚀 Deployment

• Frontend: Deployed on Vercel
• Backend: Deployed on Render

📄 License

Apache-2.0. See LICENSE file for details.

Note: The ForgeSolve name and logo are not available for reuse without explicit permission.

⚙️ Setup Instructions (Local Development)

Prerequisites

• Node.js 16+ and npm

Clone & Install

git clone https://github.com/PranshuPujara/SolveForge.git
cd SolveForge

cd backend && npm install
cd ../frontend && npm install

Run Locally

# Terminal 1 - Backend
cd backend && npm run dev

# Terminal 2 - Frontend
cd frontend && npm run dev

Visit http://localhost:5173

👤 Author

Pranshu Pujara

• GitHub: @PranshuPujara
• LinkedIn: Pranshu Pujara