ggzor/advent-of-code-2021

---

ggzor/advent-of-code-2021.json

{
  "createdAt": "2021-12-03T01:45:27Z",
  "defaultBranch": "main",
  "description": "My solutions for the Advent of Code 2021 in Scala, Python, Haskell and Rust.",
  "fullName": "ggzor/advent-of-code-2021",
  "homepage": "",
  "language": "Rust",
  "name": "advent-of-code-2021",
  "pushedAt": "2022-05-18T18:59:29Z",
  "stargazersCount": 2,
  "topics": [
    "advent-of-code",
    "advent-of-code-2021",
    "haskell",
    "polyglot",
    "python",
    "rust",
    "scala"
  ],
  "updatedAt": "2022-10-14T06:52:44Z",
  "url": "https://github.com/ggzor/advent-of-code-2021"
}

Advent of Code 2021

These are my Advent of Code 2021 solutions written in Scala 3, Haskell, Python and Rust.

Day	Title	L1	L2	L3	L4
01	Sonar Sweep	[Scala]!(day01/Day01.scala)	[Haskell]!(day01/Day01.hs#L5-L9)	[Python]!(day01/Day01.py)	[Rust]!(day01/Day01.rs)
02	Dive!	[Scala]!(day02/Day02.scala)	[Haskell]!(day02/Day02.hs#L7-L35)	[Python]!(day02/Day02.py)	[Rust]!(day02/Day02.rs)
03	Binary Diagnostic	[Scala]!(day03/Day03.scala)	[Haskell]!(day03/Day03.hs#L9-L41)	[Python]!(day03/Day03.py)	[Rust]!(day03/Day03.rs)
04	Giant Squid	[Scala]!(day04/Day04.scala)	[Haskell]!(day04/Day04.hs)	[Python]!(day04/Day04.py)	[Rust]!(day04/Day04.rs)
05	Hydrotermal Venture	[Scala]!(day05/Day05.scala)	[Haskell]!(day05/Day05.hs#L11-L30)	[Python]!(day05/Day05.py)	[Rust]!(day05/Day05.rs)
06	Lanternfish	[Scala]!(day06/Day06.scala)	[Haskell]!(day06/Day06.hs#L13-L29)	[Python]!(day06/Day06.py)	[Rust]!(day06/Day06.rs)
07	The Treachery of Whales	[Scala]!(day07/Day07.scala)	[Haskell]!(day07/Day07.hs#L10-L17)	[Python]!(day07/Day07.py)	[Rust]!(day07/Day07.rs)
08	Seven Segment Search	[Scala]!(day08/Day08.scala)	[Haskell]!(day08/Day08.hs)	[Python]!(day08/Day08.py)	[Rust]!(day08/Day08.rs)
09	Smoke Basin	[Scala]!(day09/Day09.scala)	[Haskell]!(day09/Day09.hs)	[Python]!(day09/Day09.py)	[Rust]!(day09/Day09.rs)
10	Syntax Scoring	[Scala]!(day10/Day10.scala)	[Haskell]!(day10/Day10.hs#L7-L41)	[Python]!(day10/Day10.py)	[Rust]!(day10/Day10.rs)
11	Dumbo Octopus	[Scala]!(day11/Day11.scala)	[Haskell]!(day11/Day11.hs)	[Python]!(day11/Day11.py)	[Rust]!(day11/Day11.rs)
12	Passage Pathing	[Scala]!(day12/Day12.scala)	[Haskell]!(day12/Day12.hs)	[Python]!(day12/Day12.py)	[Rust]!(day12/Day12.rs)
13	Transparent Origami	[Scala]!(day13/Day13.scala)	[Haskell]!(day13/Day13.hs)	[Python]!(day13/Day13.py)	[Rust]!(day13/Day13.rs)
14	Extended Polymerization	[Scala]!(day14/Day14.scala)	[Haskell]!(day14/Day14.hs)	[Python]!(day14/Day14.py)	[Rust]!(day14/Day14.rs)
15	Chiton	[Scala]!(day15/Day15.scala)	[Haskell]!(day15/Day15.hs)	[Python]!(day15/Day15.py)	[Rust]!(day15/Day15.rs)
16	Packet Decoder	[Scala]!(day16/Day16.scala)	[Haskell]!(day16/Day16.hs)	[Python]!(day16/Day16.py)	[Rust]!(day16/Day16.rs)
17	Trick Shot	[Scala]!(day17/Day17.scala)	[Haskell]!(day17/Day17.hs)	[Python]!(day17/Day17.py)	[Rust]!(day17/Day17.rs)
18	Snailfish	[Scala]!(day18/Day18.scala)	[Haskell]!(day18/Day18.hs)	[Python]!(day18/Day18.py)	[Rust]!(day18/Day18.rs)
19	Beacon Scanner	[Scala]!(day19/Day19.scala)	[Haskell]!(day19/Day19.hs)	[Python]!(day19/Day19.py)	[Rust]!(day19/Day19.rs)
20	Trench Map	[Scala]!(day20/Day20.scala)	[Haskell]!(day20/Day20.hs)	[Python]!(day20/Day20.py)	[Rust]!(day20/Day20.rs)
21	Dirac Dice	[Scala]!(day21/Day21.scala)	[Haskell]!(day21/Day21.hs)	[Python]!(day21/Day21.py)	[Rust]!(day21/Day21.rs)
22	Reactor Reboot	[Scala]!(day22/Day22.scala)	[Haskell]!(day22/Day22.hs)	[Python]!(day22/Day22.py)	[Rust]!(day22/Day22.rs)
23	Amphipod	[Scala]!(day23/Day23.scala)	[Haskell]!(day23/Day23.hs)	[Python]!(day23/Day23.py)	[Rust]!(day23/Day23.rs)
24	Arithmetic Logic Unit			[Python]!(day24/Day24.py)
25	Sea Cucumber	[Scala]!(day25/Day25.scala)	[Haskell]!(day25/Day25.hs)	[Python]!(day25/Day25.py)	[Rust]!(day25/Day25.rs)

Remarks

• Scala solutions are short and concise, be sure to check them out.
• The solutions are self contained, they can easily be executed as shown in the next [section]!(#running-the-solutions). This also makes them just a bit cluttered because the parsing and the part selection are inside the same file.
• Both parts of each problem are solved in the same file, this requires a bit of generalization to solve both parts with almost the same code, and makes the code longer than other solutions.
• These are not the shortest or fastest solutions, but they are readable and show the key ideas for solving each problem and how to translate them to each different language.
• The Python solutions are a bit clunky because these are the ones I code first.
• The solutions in Rust are not so good because this is the first time I use Rust for this kind of problems. It gets better day by day, but don’t expect amazing code.

Running the solutions

The solutions are self-contained and should run easily using the appropriate interpreter/compiler for each language, keeping the following considerations in mind:

• Input is taken from standard input.
• Either 1 or 2 must be passed as arguments to choose which part to run.

Scala 3

For example, to run the Scala solution for the second part of the first day, you can use the following command:

cat day01/test01.txt | scala day01/Day01.scala 2

Haskell (>= 8.10)

No other libraries apart from base, containers and mtl are used, they should be installed by default.

cat day01/test01.txt | runghc day01/Day01.hs 2

Python (>= 3.8)

Only numpy is used apart from the standard library.

cat day01/test01.txt | python3 day01/Day01.py 2

Rust (nightly >=1.62)

To run a Rust solution you must first compile it and then run the resulting executable:

rustc day01/Day01.rs
cat day01/test01.txt | ./Day01 2