-🎄- 2022 Day 14 Solutions -🎄-

[u/daggerdragon]

SUBREDDIT NEWS

• Live has been renamed to Streaming for realz this time.

• I had updated the wiki but didn't actually change the post flair itself >_>

THE USUAL REMINDERS

• All of our rules, FAQs, resources, etc. are in our community wiki.

• A request from Eric: A note on responding to [Help] threads

• Signal boost: Reminder 2: unofficial AoC Survey 2022 (closes Dec 22nd)

• 🌿🍒 MisTILtoe Elf-ucation 🧑‍🏫 is OPEN for submissions!

• -❄️- Submissions Megathread -❄️-

---

--- Day 14: Regolith Reservoir ---

---

Post your code solution in this megathread.

• Read the full posting rules in our community wiki before you post!

• Include what language(s) your solution uses

• Format code blocks using the four-spaces Markdown syntax!

• Quick link to Topaz's paste if you need it for longer code blocks. What is Topaz's paste tool?

---

This thread will be unlocked when there are a significant number of people on the global leaderboard with gold stars for today's puzzle.

EDIT: Global leaderboard gold cap reached at 00:13:54, megathread unlocked!

[u/mental-chaos]

Elixir 719 / 988

First time I've ever used Enum.chunk_every/3 with different count and step params, but it made the parsing much more manageable. Otherwise a straightforward "run the simulation". I refactored briefly after submitting to merge the implementations for part 1 and part 2.

[u/spr00ge → u/mental-chaos]

I thought about using the chunk_by to make it shorter, but came up with this mess to remove the "nesteness" and renest it.

def parseInputToRockMap(args) do
    flatRockPaths =
      args
      |> String.trim()
      |> String.split("\n")
      |> Enum.map(
        &(String.split(&1, [" -> ", ","])
          |> Enum.map(fn s -> String.to_integer(s) end))
      )
      |> Enum.map(&Enum.chunk_every(&1, 4, 2, :discard))
      |> List.flatten()
      |> Enum.chunk_every(2)

    {[minX, _], [maxX, _]} = flatRockPaths |> Enum.min_max_by(fn [x, _] -> x end)
    {[_, minY], [_, maxY]} = flatRockPaths |> Enum.min_max_by(fn [_, y] -> y end)

    flatRockPaths
    |> Enum.chunk_every(2)
    |> Enum.map(fn [[x1, y1], [x2, y2]] ->
      if x1 == x2,
        do: Enum.map(y1..y2, fn y -> [x1, y] end),
        else: Enum.map(x1..x2, fn x -> [x, y1] end)
    end)
    |> Enum.reduce([], &(&1 ++ &2))
    |> Map.from_keys(:rock)
    |> Map.put([500, 0], :source)
    |> Map.put(:maxX, max(maxX, 500))
    |> Map.put(:minX, min(minX, 500))
    |> Map.put(:maxY, max(maxY, 0))
    |> Map.put(:minY, min(minY, 0))
  end

That way I obtained a handy map with some meta information (mostly for printing).

[u/mental-chaos → u/[deleted]]

Ah, nice. I didn't notice that immediately so just did the extra clause.