Advent of Code

This repo has my solutions to Advent of Code, written in Rust.

I've tried to write idiomatic, readable code. I attempt to make my code fast, but if it's a choice between fast and readable, I choose readable. No unsafe code or SIMD here.

That said, the code is pretty fast. My solutions for 2024 run in 84ms total. I've written in detail about the optimisations I've used to make my solutions faster - Optimising my Rust solutions for Advent of Code. These tips are general and could be applied to most Rust programs.

Benchmarks

Successfully completed problems with the time taken to execute them on my M1 Pro.

2024

Day	Problem	Solution	Part 1 (ms)	Part 2 (ms)	Total (ms)
1	Historian Hysteria	Solution	0.04	0.04	0.08
2	Red-Nosed Reports	Solution	0.08	0.09	0.18
3	Mull It Over	Solution	0.22	0.22	0.44
4	Ceres Search	Solution	0.14	0.09	0.23
5	Print Queue	Solution	0.16	0.16	0.31
6	Guard Gallivant	Solution	0.08	2.55	2.63
7	Bridge Repair	Solution	0.18	5.02	5.20
8	Resonant Collinearity	Solution	0.02	0.04	0.06
9	Disk Fragmenter	Solution	0.24	0.61	0.84
10	Hoof It	Solution	0.08	0.05	0.13
11	Plutonian Pebbles	Solution	0.04	2.61	2.65
12	Garden Groups	Solution	1.09	1.94	3.03
13	Claw Contraption	Solution	0.03	0.03	0.07
14	Restroom Redoubt	Solution	0.04	0.19	0.23
15	Warehouse Woes	Solution	0.43	0.58	1.00
16	Reindeer Maze	Solution	3.01	6.38	9.39
17	Chronospatial Computer	Solution	0.00	5.35	5.35
18	RAM Run	Solution	0.27	1.15	1.42
19	Linen Layout	Solution	0.33	0.34	0.67
20	Race Condition	Solution	0.52	4.64	5.16
21	Keypad Conundrum	Solution	0.01	0.06	0.07
22	Monkey Market	Solution	1.29	34.22	35.51
23	LAN Party	Solution	0.37	7.92	8.28
24	Crossed Wires	Solution	0.03	0.05	0.07
25	Code Chronicle	Solution	0.16	0.00	0.16
		Total	8.86ms	74.33ms	83.19ms

Setup

1. Clone this repo - gh repo clone nindalf/advent or git clone [email protected]:nindalf/advent.git.
2. Install Rust or update - rustup update.
3. Install just, the command runner.
4. Install aocgen, which fetches the problem input and creates the empty files.

How to use

Run just for all the available commands.

By default just will run these for the latest year, set by the env variable AOC_YEAR.

just fetch 15         # fetches the 15th day's problem and input.

just test 15 1_t      # runs day15::tests::part1_test
just test 15 1_r      # runs day15::tests::part1_real
just test 15 1        # runs both tests for day 15 part 1
just test 15 2        # runs both tests for day 15 part 2
just test 15          # runs all 4 tests for day 15

just submit 15 1 1024 # Submit "1024" as the solution for Day 15 Part 1
just submit 15 2 2048 # Submit "2048" as the solution for Day 15 Part 2

just bench 15         # benchmarks day 15 parts 1 and 2

just test/just bench with no arguments runs all the tests/benchmarks for the latest year.

Overriding AOC_YEAR

If AOC_YEAR is not set, it picks up the default from the justfile. To run the commands for a different year, you can choose one of these options:

• Set it permanently
  • Set the env variable - export AOC_YEAR=2023
  • Change the default in the justfile - AOC_YEAR := env_var_or_default("AOC_YEAR", "2023")
• Set it for one invocation
  • AOC_YEAR=2023 just test OR
  • just --set AOC_YEAR 2023 test