Advent of Code Solver

This repository contains my solutions for the Advent of Code challenges. Each year and day have their respective directories with C# solution classes. The solutions are organized using the following structure:

/Year
    /Day01
        - Input.txt          # Real puzzle input
        - SampleInput.txt    # Sample from problem description
        - Expected.json      # Expected answers for sample input
        - SolutionClass01.cs
    /Day02
        - Input.txt
        - SampleInput.txt
        - Expected.json
        - SolutionClass02.cs
  ...

Quick Start

Create a New Solution

Run the interactive setup script:

./add_solution.sh 2025 1 SecretEntrance

You'll be prompted to paste:

• Sample input from the problem
• Expected answers (Part 1 & Part 2)
• Real puzzle input

Start Coding with Live Feedback

Launch watch mode:

./watch-solution.sh 2025 1

This opens a tmux session with:

• Top pane: Your editor (neovim) with the solution file
• Bottom pane: Auto-running tests that show results every time you save

Note: If you're already in tmux, the script will offer you options:

• Option 1: Split current window
• Option 2: Create new window
• Option 3: Just run watch mode

Every time you save your code, you'll instantly see:

━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
🎄 Advent of Code 2025 Day 1
   Watching for changes...
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

✓ Part 1: 142 ✓ (12ms)
✓ Part 2: 281 ✓ (8ms)

Last run: 14:23:45

Submit Your Answer

Once sample tests pass, get your real answers:

1. In the bottom pane: Press Ctrl+C to stop watching
2. Run: dotnet run solve -y 2025 -d 1
3. Copy the output to Advent of Code website

Commands Reference

Interactive Solution Setup

./add_solution.sh <year> <day> <solution_name>

Creates solution files and prompts for inputs.

Watch Mode (Auto-testing)

./watch-solution.sh <year> <day>

Opens tmux with live feedback on sample input.

Test Sample Input

dotnet run solve-sample -y <year> -d <day>

One-shot test against sample input with validation.

Solve Real Input

dotnet run solve -y <year> -d <day>

Run solution against real puzzle input.

Solve All Challenges

dotnet run all

Run all solutions in the repository.

Solution Structure

Solutions implement the Execute() method:

public override SolutionResult Execute(string input)
{
    // Parse input
    var lines = input.Split(['\r', '\n'], StringSplitOptions.RemoveEmptyEntries);
    
    // Your solution logic here
    
    return new SolutionResult
    {
        Part1 = "answer1",
        Part2 = "answer2"
    };
}

Expected.json Format

{
  "part1": "142",
  "part2": "281"
}

Leave values empty ("") if you don't know the answer yet:

{
  "part1": "142",
  "part2": ""
}

Testing the System

The 9999/ directory contains test solutions for validating the watch mode system:

# Test sample validation
dotnet run solve-sample -y 9999 -d 1

# Test watch mode
./watch-solution.sh 9999 1

See 9999/README.md for more details.

Tips & Tricks

Already in tmux?

If you're already in a tmux session (common workflow), ./watch-solution.sh will offer options:

• Option 1 (recommended): Splits current window - quick and keeps context
• Option 2: Creates new window - preserves your layout
• Option 3: Just runs watch mode - you open editor manually

Quick Manual Setup

If you prefer to set up manually:

# In one pane/terminal:
dotnet run watch -y 2025 -d 1

# In another pane/terminal:
nvim 2025/Day01/YourSolution.cs

Acknowledgments

Inspiration and challenges provided by Advent of Code.

https://adventofcode.com/