Advent of Code - OCaml Solutions

Advent of Code 2024 using OCaml

Getting Started

To get started with OCaml development:

• Install Opam using this link: Opam Installation Guide per OS
• Follow the guidelines on this page to setup OCaml: OCaml By Example

Quick Commands

This project includes a comprehensive Makefile with various commands to help you build, test, and run solutions efficiently.

Testing

  # Run tests for all days
  make test

  # Run tests for a specific day (e.g., day 01)
  make test-01

Code Formatting

  # Format all code using dune fmt
  make fmt

  # Format code for a specific day (e.g., day 01)
  make fmt-01

Running Solutions

  # Run a specific day with downloaded input (auto-saves answers)
  make run-day DAY=01 INPUT=download

  # Run a specific day with custom input file
  make run-day DAY=01 INPUT=path/to/input.txt

  # Run a specific day using repository inputs or fallback locations
  make run-day DAY=01 INPUT=puzzle_input

  # Run in release mode (faster execution, auto-saves answers)
  make run-release DAY=01 INPUT=download
  make run-release DAY=01 INPUT=puzzle_input

  # Run the most recently modified day with input (workflow-aware, no answer saving)"
  make run-current INPUT=download
  make run-current INPUT=puzzle_input

Project Management

  # Create a new day from template (interactive, auto-fetches problem title)
  make new-day

  # Download puzzle input (requires AUTH_TOKEN in .env file)
  make download DAY=01

  # Force download input (overwrite existing)
  make download DAY=01 FORCE=1

  # Clean all build artifacts
  make clean

Benchmarking

  # Run benchmark for a specific day
  make benchmark-01

Submission

  # Check submission status for a day
  make check-status DAY=01

  # Submit an answer (requires AUTH_TOKEN in .env file)
  make submit DAY=01 PART=1
  make submit DAY=01 PART=2

  # Run solution with interactive submission prompts
  make run-submit DAY=01 INPUT=download

Help

  # Show all available commands
  make help

🎥 Complete Automation Demo

🎄 Watch the Complete Automation Pipeline in Action!

See how this project eliminates all manual steps between solving and submitting Advent of Code solutions:

🚀 What the video demonstrates:

• Automatic puzzle input downloading with authentication
• Lightning-fast OCaml solution execution (0.3s runtime!)
• Beautiful Christmas tree visualization for Day 14 Part 2
• Smart submission system that prevents duplicate submissions
• Individual part submission (Part 1 & Part 2 separately)
• Bulk submission with interactive prompts
• Complete terminal-based workflow - no browser switching!

⚡ Key features shown:

• make new-day - Creates day template with problem title fetching
• make download DAY=14 - Auto-downloads puzzle input
• make run-current INPUT=download - Runs latest solution with downloaded input
• make submit DAY=14 PART=1 - Smart individual part submission
• make run-submit DAY=14 INPUT=download - Complete pipeline: download → run → submit

Manual Execution

For manual execution without using the Makefile commands, navigate to the specific day directory first:

cd 2024/day01

Then use the appropriate command for your operating system:

Windows:

  type "../../inputs/2024/day01.txt" | dune exec ./test.exe

Linux:

  cat "../../inputs/2024/day01.txt" | dune exec ./test.exe

Note: The Makefile commands (like make run-day DAY=01 INPUT=download) are recommended as they handle paths automatically and provide additional features like answer saving.

Configuration

Environment Variables

For automatic input downloading and submission features, create a .env file in the project root:

  AUTH_TOKEN=your_advent_of_code_session_token

You can find your session token by:

1. Going to Advent of Code
2. Logging in
3. Opening browser developer tools
4. Finding the session cookie value

Project Structure

• 2024/dayXX/ - Individual day solutions
• day_template/ - Template for creating new days
• inputs/2024/ - Downloaded puzzle inputs
• answers/2024/ - Generated answers for submission
• benchmark/ - Benchmark results

Development Setup

With Nix Flakes (Recommended)

# Enter development environment
nix develop

# Or with direnv (auto-loads when entering directory)
echo "use flake" > .envrc
direnv allow

Notes

• The parse function for each challenge question's input file was designed to handle the LF end of line sequence.