Advent of Code 2023 Solutions and Runner

Merry Advent of Code to those who celebrate!

This is a copy of my 2022 AoC Runner, without last year's solutions. It is mostly aimed at streamlining developing JavaScript solutions, but I am starting to experiment with supporting other languages. I expect the project to evolve and change over the month depending on my needs.

Contents

• Setup
  • Fetch Variables
• Usage
  • Automated Runner
  • Generate Stub Files
  • Fetch Puzzle Input
  • Write Your Solution
  • Run Your Solution
  • Test Your Solution
  • Linting
• Solutions
• Helper Utils
• Using Other Languages
• Leaderboard
• License

Setup

Ensure you have a recent version of Node.js installed, then run in your terminal:

git clone https://github.com/delventhalz/advent-of-code-2023.git
cd advent-of-code-2023/
npm install

Fetch Variables

In order to use any of the automatic fetching tools, go to your .bash_profile or .zshrc and export the following three environment variables:

export AOC_COOKIE="<copy 'Cookie' request header from adventofcode.com in dev tools>"
export AOC_REPO="<URL of repo where fetch-input.js is hosted>"
export AOC_CONTACT="<your email address>"

Usage

Automated Runner

There is an automated runner, written in bash which will string together the following commands and run your whole solve. To use it for today's problem, just run it:

./go

Note, if used after 11pm EST, the runner will wait for tonight's problem to start rather than running today's.

To use the runner with a different year and day, specify them as command line args:

./go 2023 5

1. Generate Stub Files

Begin your solution by first generating stub files:

npm run generate

This will create a new directory with three files:

• 1.js
• 2.js
• input.txt

By default, the directory will be named "wip" and be gitignored. The default can be overridden with a command line arg.

npm run generate <directory name>

The headers in the JavaScript files will be populated with references to the day and year of the upcoming Advent of Code problem (i.e. tomorrow). You may want to manually adjust if that isn't valid for the problem you are working on.

2. Fetch Puzzle Input

Although it is easy enough to copy and paste puzzle input from the web into the input.txt file, if you want to do it in the command line, you can do that as well.

npm run fetch

This will fetch your most recent puzzle input and save it to wip/input.txt, overwriting any existing text there.

If you would like to specify a different file path, you can do so with a command line argument, just beware that any existing files at that path will be overwritten:

npm run fetch <relative file path>

3. Write Your Solution

Once your puzzle inputs are in input.txt. The runner will read these inputs, parse them, and pass them to your solution files.

Each solution file should export a function as a default export.

export default function main({ input }) {

    // Calculate solution...

    return solution;
}

• Parameters
  • inputMap - An object with different parses of the input string under different properties. Destructure the property you need.
    • input - Raw unparsed string version of input.txt.
    • lines - An array of each line from input.txt.
    • matrix - The input.txt characters broken up into a 2D array with each character as its own cell.
    • parsed - An attempt to cleverly parse the input.txt file. Typically an array, possibly a deeply nested array. The parser progressively splits the input string on any sensible delimiters (blank lines, new lines, commas), and then parses any numbers. If the input contains no sensible delimiters, this is just the raw string.
• Returns
  • The solution you calculated. Will be logged to the console by the runner.

Lodash and a few custom utilities are available as ES modules as well.

import { chunk } from 'lodash-es';

Of course new modules can be installed with NPM:

npm install <module name>

4. Run Your Solution

Once the solution file is complete, and the input string is in input.txt, running your solution can be done with the npm start command, with the path to the solution file provided as the single argument:

npm start <path to solution file>

5. (Optional) Test Your Solution

For particularly troublesome problems, Mocha/Chai is available. Simply create a unit test file in your solution folder and name it with the .test.js suffix.

To run all .test.js files:

npm test

To test only a single file, use the -- option to pass the path to the test file as a command line argument to the npm script:

npm test -- <path to test file>

Linting

A basic linter is included to catch stupid errors. It will automatically check all files before running your solution, though errors will not stop the run. To run the linter manually:

npm run lint

Solutions

Any solutions of mine will be in numbered directories, and should run correctly with the tools above. Reference or run them as you will.

Helper Utils

For the most part I just copied and pasted the code I reused. But if a particular function was repeatedly useful across multiple nights, I pulled it out into a module, and put that module in the lib/ directory. These can all be imported from lib/index.js:

import { sum } from '../lib/index.js';

const nums = [1, 2, 3];
console.log(sum(nums));  // 6

Using Other Languages

For this year I am playing around more with languages other than JavaScript. To that end I have created a simple run script which can compile and run solution files:

./run <path to solution file>

Currently the script supports:

• JavaScript - requires node
• Python - requires python
• C - requires gcc
• Rust - requires rustc (install here)
• Clojure - requires clj (install here)

For non-JS languages, the support is very basic. There is no parsing of input.txt and no logging of the solution. The source file is simply compiled and then run.

Leaderboard

In past years I have competed on caderek's leaderboard. Assuming it is still active, I will stay on it this year as well, and you can join yourself with this code:

107172-b51ab08f

I am also using my own leaderboard with a few friends, which you can join with this code:

472347-2b04474b

License

"Advent of Code" and all Advent of Code related content are property of Advent of Code and protected by copyright:

https://adventofcode.com/2023/about#legal

All solution code and associated tools were written by me, Zac Delventhal, and are made available under the MIT open source license.