Advent of Code

This is a C# repository template for your Advent of Code solutions. I've been using this since 2015 with great success.

It's not a command line tool, but rather a batteries included framework that does the heavy lifting. While you focus on solving the problems it provides:

• input download
• a solution skeleton generator
• online answer validation
• regression tests
• speed tests
• up to date calendar in ANSI colors for the terminal, as well as an SVG version for your README.md
• source lines of code (sloc) chart
• an OCR for elf fonts.

Due to copyright reasons I'm not allowed to include input files and problem descriptions within this repository. But I wanted to have a self contained version for myself that I can keep around forever, so decided to commit the encrypted version of the input files. It doesn't violate the copyright since it's just random garbage for everyone else but when I check it out, a plugin called git-crypt decrypts all my inputs transparently, so that I can work with them uninterrupted.

On commit the whole process is reversed and the files get encrypted again.

Dependencies

• Based on .NET 10 and C# 14
• AngleSharp is used for problem download
• git-crypt to store the input files in an encrypted form
• the optional Memento Inputs extension for Visual Studio Code

Getting started in 5 steps

1. Clone the repo
2. Install .NET
3. Install and initialize git-crypt:

> brew install git-crypt
> cd repo-dir
> git-crypt init
> git-crypt export-key ~/aoc-crypt.key

Don't commit aoc-crypt.key into a public repo, back it up in some protected place. If you need to clone your repo later you will need to unlock it using this key such as:

> git clone ...
> cd repo-dir
> git-crypt unlock ~/aoc-crypt.key

4. export your SESSION cookie from the adventofcode.com site in your terminal as an env variable:

> export SESSION=djsaksjakshkja...

5. Get help with dotnet run and start coding.

Working in Visual Studio Code

If you prefer, you can work directly in VSCode as well.

Open the command Palette (⇧ ⌘ P), select Tasks: Run Task then e.g. update today.

Work on part 1. Check the solution with the upload today task. Continue with part 2.

Note: this feature relies on the "Memento Inputs" extension to store your session cookie, you need to set it up in advance from the Command Palette with Install Extensions.