Advent of Code Elixir

Solutions for Advent of Code in Elixir.

Inspired from Advent of Code Rust.

Important

DON'T make the advent of code puzzle inputs public. Do one of the following:

1. Make your repository private.
2. Or add those lines to your .gitignore file:

input.txt
example-*.txt

Benchmarks

Year	Day	Part 1	Part 2

Template Setup

1. Use this link to create your repository.
2. Clone the repository to your computer.
3. Use mix aoc.scaffold and start coding!!!

Important

Make sure not to use the Logger module for logging, some tasks like aoc.test suppress IO output, this does work for the Logger module, but then the output wont be in the right order...

Usage

Arguments

You can pass arguments in three different ways.

1. As key value pair: --<key>=<value>

2. As key only, will set the value to true: --<key>

3. As value only, this will try to match values to a key: <value>

   E.g. if you pass 2025 will know it is a year because it has 4 digits and is in range from 2000 to 2099. Days can also be recognized because they are 1 or 2 digits and are in range from 1 to 25.

Tip

You can get more information about arguments and more examples by running: mix help aoc.<command>.

Scaffolding

# example: mix aoc.scaffold 2025 1
mix aoc.scaffold --year=<year> --day=<day>

# output:
# Created elixir file: lib/bin/Y2025/D01.ex
# Created input file: puzzles/Y2025/D01/input.txt
# Created example file: puzzles/Y2025/D01/example-1.txt
# Created .keep file: data/Y2025/D01/.keep

Tip

You can add more examples by adding an example file with a different number, something like this: example-2.txt. You can only use integers, no letters...

Tip

To specify wich example input your test should use you can change the example option in the generated elixir file.

Read the comments.

defmodule Bin.Y2025.D01 do
	def part_one(_input) do
		# Code for part one
		nil
	end

	def part_two(_input) do
		# Code for part two
		nil
	end

	def tests do
		[
			# - `part`: Is the atom of the function that will be called from the test.
			# - `result`: Is the expected result returned from the function.
			# - `example`: Specifies which example file to use (../example-<example>.txt).
			[part: :part_one, result: nil, example: 1],
			[part: :part_two, result: nil, example: 1],
			# Feel free to add more tests here.
		]
	end
end

Testing

# example: mix aoc.test 2025 1
mix aoc.test --year=<year> --day=<day>

# output:
# Testing lib/bin/Y2025/D01.ex
# ----------------------------
# Testing part_one
# Part One succeded in 0.003ms
# Testing part_two
# Part One succeded in 0.001ms

This task will run all tests specified in the tests/0 function of the solution file.

Solving

# example: mix aoc.solve 2025 1
mix aoc.solve --year=<year> --day=<day>

# output:
# Solve part one.
# Solve part two.
# -------------
# Part One (0.002ms): ✖		 # function returned nil
# Part Two (0.002ms): 42

This task will run part one and two, and display the results.

Benchmarking

# example: mix aoc.bench 2025 1
mix aoc.bench --year=2025 --day=1

# output:
# Benching lib/bin/Y2025/D01.ex
# -----------------------------
# part_one returned nil, skipping.
# part_two: 0.001ms (5)