/advent-of-code-2024

My Rust solutions to Advent of Code 2024

Primary LanguageRustMIT LicenseMIT

Advent of Code 2024 🦀

These are my Rust solutions for Advent of Code 2024.

My AoC solutions for other years

Initial setup

Fedora

dnf install just entr

Example commands

Purpose Command
List all commands just --list
Start day 1 just day 1
Run day 3 on file change just watch run 3
Run day 16 with example input just run 16 -e
Run day 3 part 1 only just run 3 -p 1
Run day 1 with custom input just run 1 -i examples/custom_input_file
Run day 21 in release mode just r 21
Run tests just test
Run tests for day 13 just test 13
Run all tests just test_all

cargo run can be used directly, but

Session setup

Create an environment variable named AOC_SESSION that contains your Advent of Code session cookie's value.

Start a new day

The command just day N (where N is the day number, from 1 to 25), will scaffold and open all1 the files needed for that day.

just day 1

This will do the following actions, only as needed:

  1. Download input for day 1 and save it to input/d1
  2. Create a blank example file examples/d1
  3. Create src/d1.rs from the template at templates/d.rs (and add the module to src/lib.rs)
  4. Open the source file, input file, and example file in vim

Watch for changes

The just watch command can be used to run any other command when a given day's files are changed. Here are some examples.

Command Purpose
just watch run 10 Run day 10 when any of day 10's files change.
just watch test 10 Run day 10's tests when any of day 10's files change.
just watch r 10 Run day 10 in release mode when any of day 10's files change.

Day 10's files include src/d10.rs, input/d10, examples/d10, and even examples/d10-another-example (the hyphen after the number is required).

If you're curious which files are being watched, try just files 10 to print the matched files.

Note: a running watch command will only watch files that existed at the time it was launched. If new files are added, re-run the watch command.

Days with multiple examples

# run with the example input in the default example file: examples/d12
just run 12 -e

# run with example inputs you saved to examples/d12-2 and examples/d12-3
just run 12 -i examples/d12-2
just run 12 -i examples/d12-3

Adding tests

If you like to tweak solutions after finding the answer, it can be helpful to write a simple test.

Pros

  • Fast compilation (pico-args is the only dependency)
  • Fast LSP startup
  • No magical-feeling macros
  • All the code (other than pico-args) is here in the repo, so it can be changed on a whim

Cons

  • No benchmarks

Footnotes

  1. Most days contain only one example input, but some contain more. For multi-example days, create more example files in the examples directory with names of your choosing, and use -i/--input to use them. Here's 2021 day 12 as an example, which contains three examples. Let's say you save the first example in the default location examples/d12, the second to examples/d12-2 and the third to examples/d12-3. ↩