Advent of Code Solutions 2025 🎄

Rust solutions for Advent of Code puzzles with a beautiful Ratatui TUI interface and automatic day discovery.

✨ Features

• 🎨 Beautiful TUI - Full-featured terminal UI with Ratatui
• 🔍 Auto-Discovery - Automatically detects available days from source files
• 📝 Smart Parsing - Extracts day titles from code comments
• 🚀 CLI Mode - Quick command-line interface for scripting
• 📁 Flexible Input - Support for files, default files, or stdin
• 🎯 Zero Config - No need to manually register days in main.rs
• ⚡ Fast - Written in Rust for maximum performance

🚀 Quick Start

# Clone and build
git clone <your-repo>
cd adventcode
cargo build --release

# Run the interactive TUI (just run with no args!)
cargo run

# Or run a specific day directly
cargo run -- --day 5 --part2

🎨 Screenshots

Main Menu

╔════════════════════════════════════════╗
║                                        ║
║    🎄 Advent of Code Runner 🎄        ║
║                                        ║
╚════════════════════════════════════════╝

┌ Available Days ───────────────────────┐
│ ▶ Day  1: COMBINATION LOCK [✓]       │
│   Day  2: INVALID ID DETECTION [✓]   │
│   Day  3: LOBBY BATTERIES [✓]        │
│   Day  4: PRINTING DEPARTMENT [✓]    │
│   Day  5: CAFETERIA [✓]              │
└───────────────────────────────────────┘

↑↓: Navigate | Enter: Select | q: Quit

Part Selection

┌──────────────────────────────────────┐
│      Day 5: CAFETERIA                │
└──────────────────────────────────────┘

┌ Select Part ─────────────────────────┐
│                                      │
│         ▶ Part 1                     │
│                                      │
│           Part 2                     │
└──────────────────────────────────────┘

↑↓: Select Part | Enter: Run | Backspace: Back | q: Quit

📖 Usage

🎨 Interactive TUI Mode (Recommended)

Simply run without any arguments:

cargo run

Navigation:

• ↑/↓ or k/j - Navigate through days/parts
• Enter - Select day or run puzzle
• Backspace - Go back to day selection
• q or Esc - Quit

The TUI will show:

• All available days with their titles (auto-detected!)
• Input file status (✓ if exists, ✗ if missing)
• Beautiful interface with syntax highlighting

⚡ Command-Line Mode

Run a specific day with explicit arguments:

# Part 1 with default input file (day1.txt)
cargo run -- --day 1

# Part 2 with custom input file
cargo run -- --day 1 --file input.txt --part2

# Quiet mode (no formatting, just output)
cargo run -- --day 1 --file input.txt --quiet

🎯 Short Flags

cargo run -- -d 1              # Day 1, Part 1, default file
cargo run -- -d 1 -2           # Day 1, Part 2, default file
cargo run -- -d 1 -f input.txt # Day 1, Part 1, custom file
cargo run -- -d 5 -2 -q        # Day 5, Part 2, quiet mode

📥 Using Stdin

Pipe input directly:

cat input.txt | cargo run -- -d 1 -q
echo "L68\nR30" | cargo run -- -d 1 -2 -q
cargo run -- -d 1 -q < input.txt

❓ Help

View all available options:

cargo run -- --help

🔧 Adding New Days - It's Automatic! 🎉

No more manual registration! Just create your day file and it's automatically detected.

1. Create the solution file

Create src/dayN.rs with the proper header format:

// ============================================================================
// DAY N: YOUR TITLE HERE
// ============================================================================
//
// PROBLEM OVERVIEW:
// -----------------
// Description of the problem...
//
// Part 1: What part 1 asks for
// Part 2: What part 2 asks for
//
// ============================================================================

pub fn solve(input: &str, part2: bool) {
    if part2 {
        // Part 2 logic
        println!("{}", result);
    } else {
        // Part 1 logic
        println!("{}", result);
    }
}

Important: The title is extracted from the comment // DAY N: YOUR TITLE

2. Add module declaration to main.rs

Just add ONE line to the top of src/main.rs:

mod dayN;

And add ONE match arm:

match day {
    // ...
    N => dayN::solve(&input, part2),
    _ => eprintln!("Day {} not implemented yet", day),
}

3. Add input file (optional)

Create dayN.txt with your puzzle input.

4. That's it! 🎉

The system will automatically:

• ✅ Detect the new day exists
• ✅ Extract the title from comments
• ✅ Check if input file exists
• ✅ Show it in the TUI menu
• ✅ Allow you to run it

No need to update:

• ❌ Day lists
• ❌ Menu items
• ❌ Title arrays
• ❌ Configuration files

🎯 How Auto-Discovery Works

The system scans src/ for files matching day*.rs (day1.rs through day25.rs) and:

1. Detects existence - Checks which day files are present
2. Extracts titles - Parses the header comment // DAY N: TITLE
3. Checks input - Verifies if dayN.txt exists
4. Populates TUI - Automatically shows all found days

Title Format

The title is extracted using regex pattern:

// DAY \d+: (.+)

Examples:

// DAY 5: CAFETERIA           → Title: "CAFETERIA"
// DAY 1: COMBINATION LOCK    → Title: "COMBINATION LOCK"
// DAY 10: SUPER COOL PUZZLE  → Title: "SUPER COOL PUZZLE"

📁 Input Files

By default, the program looks for dayN.txt files:

1. Use default files: Place input in day1.txt, day2.txt, etc.
2. Specify custom file: Use --file custom.txt
3. Use stdin: Pipe input when file doesn't exist

The TUI shows input status:

• [✓] - Input file exists
• [✗] - No input file (will prompt or use stdin)

🎨 Output Examples

With TUI/CLI formatting:

────────────────────────────────────────────────────────────
🎄 Day 5: CAFETERIA │ Part 2
────────────────────────────────────────────────────────────
Result: 357907198933892

Quiet mode:

357907198933892

📂 Project Structure

adventcode/
├── src/
│   ├── main.rs      # Auto-discovering CLI and TUI
│   ├── day1.rs      # Day 1: COMBINATION LOCK
│   ├── day2.rs      # Day 2: INVALID ID DETECTION
│   ├── day3.rs      # Day 3: LOBBY BATTERIES
│   ├── day4.rs      # Day 4: PRINTING DEPARTMENT
│   ├── day5.rs      # Day 5: CAFETERIA
│   └── ...          # Add more days as needed
├── day1.txt         # Input files (optional)
├── day2.txt
├── day3.txt
├── day4.txt
├── day5.txt
├── demo.sh          # Demo script
├── Cargo.toml
└── README.md

🎯 Solutions

Day	Title	Part 1	Part 2	Status
1	Combination Lock	⭐	⭐	✅
2	Invalid ID Detection	⭐	⭐	✅
3	Lobby Batteries	⭐	⭐	✅
4	Printing Department	⭐	⭐	✅
5	Cafeteria	⭐	⭐	✅

Brief Descriptions

• Day 1: COMBINATION LOCK - Circular dial rotation with position tracking
• Day 2: INVALID ID DETECTION - Finding repeated digit sequences in numeric ranges
• Day 3: LOBBY BATTERIES - Maximum joltage from battery digit combinations
• Day 4: PRINTING DEPARTMENT - Grid-based paper roll accessibility counting
• Day 5: CAFETERIA - Fresh ingredient ID range merging and counting

📦 Dependencies

• clap (v4.5) - Command-line argument parsing
• ratatui (v0.29) - Terminal user interface library
• crossterm (v0.28) - Terminal manipulation
• regex (v1.11) - Pattern matching for auto-discovery

🎓 What Makes This Special

🔍 Auto-Discovery System

Unlike traditional Advent of Code runners, this project:

• No manual registration - Just create dayN.rs and it's detected
• Smart title extraction - Parses your code comments automatically
• Input validation - Shows which days have input files ready

🎨 Beautiful TUI with Ratatui

• Professional terminal interface
• Smooth keyboard navigation
• Color-coded status indicators
• Responsive layout

⚡ Developer-Friendly

• Add days in seconds, not minutes
• Consistent code structure
• Comprehensive documentation in each file
• Easy to extend and maintain

🎓 Learning Resources

This project demonstrates:

• ✅ Rust module system and project structure
• ✅ File system operations and regex parsing
• ✅ TUI development with Ratatui
• ✅ CLI design with clap
• ✅ Pattern matching and error handling
• ✅ Clean code organization

📝 License

MIT

🤝 Contributing

Feel free to:

• Add more days (it's automatic!)
• Improve solutions
• Enhance the TUI
• Add features
• Fix bugs

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Made with ❤️ and 🦀 Rust