Advent of Code Project Template

A lightweight execution environment for the advent of code challenges written in Go.

Get started

In the following section, I'll show you how to set up and run the environment for the challenges.

Prerequisites

Make sure you have Go >= 1.21.4 installed.

Clone the repository

git clone https://github.com/wlchs/advent_of_code_go_template

Solve the daily challenges.

I've generated a separate directory in the repository for each advent calendar day: from the 1st until the 24th. Additionally, the day_0 directory contains a solution for the first challenge from last year's competition.

To solve a daily challenge, navigate to the corresponding day and implement the solution. I've prepared two methods for each day, Part1 andPart2, indicating that every challenge has two parts. The return value of the methods are always strings. The methods receive the input as a string slice, so you don't have to worry about reading anything from a file.

The solution for the challenge of December 1, 2022, looks like this:

// getElfCalories reads the input lines and returns a slice of calories for each elf
func getElfCalories(input []string) []int {
    var calories []int
    currentElf := 0
    for _, i := range input {
        if i == "" {
            calories = append(calories, currentElf)
            currentElf = 0
        } else {
            cal, _ := strconv.Atoi(i)
            currentElf += cal
        }
    }
    calories = append(calories, currentElf)
    sort.Slice(calories, func (i, j int) bool {
        return calories[i] > calories[j]
    })
    return calories
}

// Part1 solves the first part of the exercise
func Part1(input []string) string {
    calories := getElfCalories(input)
    maxCalories := calories[0]
    return strconv.Itoa(maxCalories)
}

// Part2 solves the second part of the exercise
func Part2(input []string) string {
    calories := getElfCalories(input)
    topCalories := 0
    for i := 0; i < 3; i++ {
        topCalories += calories[i]
    }
    return strconv.Itoa(topCalories)
}

Additionally, I've prepared unit tests for each day to try the solutions with a template input. The text files in the directories contain the template input and output for both parts of the exercise. Paste the input to input_test_x.txt file and the expected solution tosolution_x.txt.

Test your solution

Before submitting a solution, you can test your algorithm with the template input. Navigate to the day you want to check and run the following command:

go test

Alternatively, you can also run the command from the project root.

go test ./days/day_xx/

Compile and run

You can compile code and run with the actual input if all the tests pass. For this, first, run this command:

go build .

To run the solution, you need to provide a few extra arguments.

• the --day flag must be set to specify which day's solution should run
• the --input flag specifies the path of the file containing the actual input
• optionally, you can add the --mode flag to run one part of the daily challenge, accepted values are 1 and 2

And now the complete command:

./advent_of_code_go_template --day x --input path_to_input --mode 1
# or
go run . --day x --input path_to_input --mode 1

Contribution

If you'd like to contribute to the project, open an issue or a pull request!