Advent of Code Solutions 🎄

My solutions to puzzles at adventofcode.com. Also check out my collected tricks ✨.

See also:

• erikw/hackerrank-solutions
• erikw/kattis-solutions
• erikw/leetcode-solutions
• erikw/project-euler-solutions

2024 Results

Day	Part 1	Part 2

All Results

Development Setup

Per Environment

macOS

brew bundle install

Debian/Ubuntu

sed 's/#.*$//' < apt-packages.txt | xargs sudo apt-get -y install

Ruby

bundle install

JavaScript

npm install

Python

pip install -r requirements.txt

Session Cookie

Fetch your AoC Session Cookie and set it up as an environment variable by either:

• putting it a .env file in the repo's root dir as AOC_SESSION=...
• export in your shell ('s startup file) as export AOC_SESSION=....

Solve a Puzzle

and now solve today's puzzle or a specific one:

bin/solve_day.sh           # Solve today's puzzle with default lanuage (ruby)
bin/solve_day.sh 19/5      # 2019 day 5
bin/solve_day.sh -l py     # Solve with language, here Python

To fetch input for an already solved problem:

bin/fetch_input.sh yy/mm

Tip

The default language can be set with an envvar, e.g. with dotenv in a .env file which is also read by bin/solve_day.sh:

echo AOC_LANG=py >> .env

Session Cookie Expired?

Update:

• AOC_SESSION in local .env for local development.
• AOC_SESSION in Codespaces secrets for GitHub Codespaces development.
• AOC_SESSION in Action Secret for .github/workflows/readme-stars.yml.
• SESSION in Vercel Envvar for erikw/adventofcode-badge.
  • Then redeploy to restart the service.