Advent of Code - Go Project Template

A template structure for writing your Advent of Code puzzle solvers in Go and printing the solution to stdout.

> go run . 1 1  # prints solution for day 1 part 1

Clone the main branch only (so you don't get my own branches):

git clone --single-branch --branch main https://github.com/al-ce/aoc-go-template.git

Project structure

├── inputs
│   ├── 1
├── internal
│   ├── helpers
│   │   └── helpers.go
│   └── imports
│       └── imports.go
└── solutions
    ├── day01
    │   ├── day01.go
    │   └── test01
    │       └── test01.go

Download the input for day N (no leading zeros) in inputs/ (please note that inputs/ is in .gitignore so you don't commit the input data).

An example with aocgofetch:

> aocgofetch 2024 1 > inputs/1

Finally, create a new git branch for the year you are solving so you'll have a clean template for next year!

Writing a test

Take the example input from the daily instructions and replace the values for lines, partOneAnswer, and partTwoAnswer in the test template. For example, day 1 of 2024 would look like this:

var lines = strings.Split(`3   4
4   3
2   5
1   3
3   9
3   3`, "\n")

var partOneAnswer = "11"
var partTwoAnswer = "31"

After writing the solution, run the test:

❯ go test go-aoc-template/solutions/day1
ok      go-aoc-template/solutions/day1  0.001s

This might not cover any edge cases from the actual puzzle input.

Writing your solution

Fill out PartOne() and PartTwo() in the day's template with each part's solution. See solutions/day1/day1.go for reference.

Helpers can go in internal/helpers/helpers.go. In main.go, the provided InputLines() helper generates the lines from the input file and passes them as a string slice to PartOne() and PartTwo().

justfile

This is the justfile I use to help my workflow.

set quiet
releasepath := './bin/aocgosolutions'
_dayf := "'$(printf %02d)'"

get year day:
    aocgofetch {{year}} {{day}} > inputs/{{day}}

solve day:
    mkdir -p bin && go build -o {{releasepath}} go-aoc-template && {{releasepath}} {{day}}

test day:
    go run $(printf "./solutions/day%02d/test%02d/test%02d.go" {{day}} {{day}} {{day}})

setup day:  # Create template for a specific day (!overwrites current file!)
    ./setup.sh {{day}}

everyday:  # Create template for every day (!overwrites all files!)
    bash -c 'for i in {1..25}; do just setup "$i"; done'