Day 05

Mix.install([
  {:kino_aoc, git: "https://github.com/ljgago/kino_aoc"}
])

:ok

Setup

{:ok, puzzle_input} =
  KinoAOC.download_puzzle("2022", "5", System.fetch_env!("LB_ADVENT_OF_CODE_SESSION"))

{:ok,
 "[N]     [C]                 [Q]    \n[W]     [J] [L]             [J] [V]\n[F]     [N] [D]     [L]     [S] [W]\n[R] [S] [F] [G]     [R]     [V] [Z]\n[Z] [G] [Q] [C]     [W] [C] [F] [G]\n[S] [Q] [V] [P] [S] [F] [D] [R] [S]\n[M] [P] [R] [Z] [P] [D] [N] [N] [M]\n[D] [W] [W] [F] [T] [H] [Z] [W] [R]\n 1   2   3   4   5   6   7   8   9 \n\nmove 1 from 3 to 9\nmove 3 from 5 to 3\nmove 4 from 2 to 5\nmove 4 from 1 to 2\nmove 3 from 5 to 7\nmove 3 from 1 to 2\nmove 4 from 8 to 7\nmove 4 from 9 to 7\nmove 4 from 2 to 7\nmove 2 from 3 to 6\nmove 3 from 6 to 2\nmove 5 from 4 to 7\nmove 7 from 3 to 7\nmove 5 from 6 to 9\nmove 2 from 4 to 8\nmove 1 from 3 to 2\nmove 4 from 2 to 7\nmove 2 from 2 to 8\nmove 8 from 8 to 5\nmove 1 from 2 to 4\nmove 1 from 2 to 9\nmove 7 from 5 to 4\nmove 31 from 7 to 1\nmove 9 from 9 to 3\nmove 12 from 1 to 9\nmove 15 from 1 to 7\nmove 4 from 3 to 8\nmove 2 from 5 to 1\nmove 12 from 7 to 5\nmove 2 from 8 to 2\nmove 12 from 5 to 4\nmove 1 from 3 to 5\nmove 6 from 1 to 3\nmove 1 from 1 to 5\nmove 1 from 8 to 7\nmove 1 from 8 to 5\nmove 7 from 7 to 8\nmove 5 from 8 to 2\nmove 11 from 4 to 2\nmove 10 from 3 to 1\nmove 1 from 7 to 5\nmove 10 from 1 to 3\nmove 5 from 4 to 2\nmove 1 from 4 to 6\nmove 7 from 2 to 3\nmove 9 from 9 to 5\nmove 15 from 2 to 3\nmove 1 from 9 to 1\nmove 7 from 5 to 3\nmove 1 from 2 to 4\nmove 2 from 9 to 2\nmove 1 from 8 to 9\nmove 5 from 5 to 3\nmove 1 from 8 to 7\nmove 1 from 2 to 4\nmove 1 from 7 to 6\nmove 1 from 1 to 6\nmove 1 from 6 to 9\nmove 1 from 5 to 4\nmove 1 from 6 to 4\nmove 1 from 6 to 8\nmove 2 from 9 to 4\nmove 12 from 3 to 1\nmove 8 from 4 to 8\nmove 1 from 9 to 8\nmove 10 from 8 to 6\nmove 1 from 6 to 7\nmove 6 from 6 to 9\nmove 1 from 2 to 7\nmove 1 from 4 to 7\nmove 2 from 7 to 3\nmove 1 from 1 to 3\nmove 6 from 9 to 1\nmove 2 from 6 to 7\nmove 12 from 1 to 3\nmove 5 from 1 to 9\nmove 1 from 7 to 3\nmove 38 from 3 to 7\nmove 19 from 7 to 8\nmove 19 from 8 to 2\nmove 1 from 9 to 6\nmove 5 from 3 to 7\nmove 2 from 6 to 7\nmove 1 from 3 to 9\nmove 2 from 3 to 6\nmove 4 from 2 to 6\nmove 6 from 2 to 4\nmove 14 from 7 to 9\nmove 8 from 2 to 5\nmove 19 from 9 to 3\nmove 6 from 4 to 1\nmove 6 from 1 to 4\nmove 4 from 4 to 3\nmove 10 from 7 to 6\nmove 1 from 6 to 4\nmove 22 from 3 to 1\nmove 5 from 1 to 6\nmove 5 from 5 to 8\nmove 1 from 7 to 4\nmove 1 from 2 to 3\nmove 15 from 6 to 9\nmove 3 from 8 to 4\nmove 2 from 3 to 1\nmove 6 from 9 to 1\nmove 1 from 3 to 9\nmove 1 from 3 to 1\nmove 1 from 5 to 9\nmove 1 from 7 to 1\nmove 1 from 8 to 2\nmove 6 from 9 to 2\nmove 2 from 9 to 1\nmove 3 from 6 to 3\nmove 2 from 9 to 5\nmove 1 from 6 to 7\nmove 2 from 2 to 7\nmove 3 from 3 to 5\nmove 1 from 8 to 9\nmove 7 from 4 to 7\nmove 1 from 6 to 3\nmove 2 from 9 to 5\nmove 10 from 1 to 5\nmove 19 from 1 to 8\nmove 9 from 7 to 1\nmove 1 from 3 to 5\nmove 2 from 2 to 4\nmove 2 from 2 to 6\nmove 2 from 6 to 4\nmove 7 from 1 to 7\nmove 3 from 7 to 3\nmove 2 from 4 to 1\nmove 3 from 3 to 4\nmove 1 from 2 to 4\nmove 2 from 4 to 1\nmove 2 from 4 to 8\nmove 20 from 8 to 2\nmove 1 from 8 to 3\nmove 4 from 7 to 8\nmove 14 from 2 to 6\nmove 3 from 1 to 2\nmove 2 from 1 to 7\nmove 1 from 4 to 6\nmove 1 from 1 to 5\nmove 4 from 2 to 8\nmove 3 from 7 to 6\nmove 1 from 4 to 6\nmove 2 from 7 to 9\nmove 1 from 2 to 6\nmove 1 from 3 to 1\nmove 3 from 5 to 8\nmove 1 from 1 to 4\nmove 2 from 9 to 5\nmove 4 from 6 to 7\nmove 1 from 4 to 1\nmove 1 from 8 to 5\nmove 1 from 7 to 6\nmove 1 from 2 to 9\nmove 2 from 7 to 1\nmove 1 from 1 to 3\nmove 1 from 7 to 2\nmove 4 from 2 to 7\nmove 1 from 1 to 3\nmove 2 from 3 to 2\nmove 9 from 8 to 3\nmove 1 from 8 to 6\nmove 2 from 7 to 3\nmove 1 from 7 to 4\nmove 1 from 9 to 7\nmove 1 from 7 to 2\nmove 2 from 2 to 8\nmove 6 from 5 to 2\nmove 5 from 3 to 7\nmove 1 from 4 to 7\nmove 3 from 7 to 1\nmove 11 from 5 to 8\nmove 2 from 1 to 6\nmove 2 from 1 to 8\nmove 2 from 5 to 9\nmove 1 from 7 to 2\nmove 2 from 5 to 4\nmove 17 from 6 to 7\nmove 1 from 4 to 1\nmove 1 from 1 to 7\nmove 1 from 6 to 5\nmove 1 from 6 to 2\nmove 9 from 2 to 5\nmove 1 from 6 to 7\nmove 9 from 7 to 4\nmove 3 from 7 to 8\nmove 3 from 3 to 4\nmove 8 from 7 to 9\nmove 11 from 8 to 1\nmove 1 from 4 to 3\nmove 1 from 7 to 4\nmove 9 from 9 to 4\nmove 5 from 1 to 7\nmove 8 from 5 to 1\nmove 3 from 3 to 4\nm" <> ...}

[crates, moves] = String.split(puzzle_input, "\n\n")

moves =
  moves
  |> String.split("\n", trim: true)
  |> Enum.map(fn move ->
    Regex.named_captures(~r/move (?\d+) from (?\d) to (?\d)/, move)
    |> Map.new(fn {k, v} -> {String.to_atom(k), String.to_integer(v)} end)
  end)

crates =
  crates
  |> String.split("\n")
  |> Enum.drop(-1)
  |> Enum.map(fn line ->
    line
    |> String.to_charlist()
    |> Enum.chunk_every(4)
    |> Enum.map(fn
      [?[, n, ?] | _] -> n
      _ -> nil
    end)
  end)
  |> Enum.zip()
  |> Enum.map(fn column -> column |> Tuple.to_list() |> Enum.drop_while(&is_nil/1) end)
  |> Enum.with_index(1)
  |> Map.new(fn {v, k} -> {k, v} end)

%{
  1 => 'NWFRZSMD',
  2 => 'SGQPW',
  3 => 'CJNFQVRW',
  4 => 'LDGCPZF',
  5 => 'SPT',
  6 => 'LRWFDH',
  7 => 'CDNZ',
  8 => 'QJSVFRNW',
  9 => 'VWZGSMR'
}

defmodule Day05 do
  def move(%{count: count, from: from, to: to}, columns, reverse? \\ true) do
    {moved, columns} = Access.get_and_update(columns, from, &Enum.split(&1, count))

    moved = if reverse?, do: Enum.reverse(moved), else: moved

    Map.update!(columns, to, &(moved ++ &1))
  end

  def eval(crates, moves, reverse? \\ true) do
    moves
    |> Enum.reduce(crates, &Day05.move(&1, &2, reverse?))
    |> Enum.sort()
    |> Enum.map(fn {_, v} -> hd(v) end)
  end
end

{:module, Day05, <<70, 79, 82, 49, 0, 0, 13, ...>>, {:eval, 3}}

Task 1

Day05.eval(crates, moves)

'FWNSHLDNZ'

Task 2

Day05.eval(crates, moves, false)

'RNRGDNFQG'