Advent of Code 2024 - Day 25

Mix.install([
  {:kino_aoc, "~> 0.1.7"}
])

Section

{:ok, puzzle_input} =
  KinoAOC.download_puzzle("2024", "25", System.fetch_env!("LB_AOC_SESSION"))

{locks, keys} =
  puzzle_input
  |> String.split("\n\n")
  |> Enum.split_with(&amp;match?("#" <> _, &amp;1))

locks =
  locks
  |> Enum.map(fn str ->
    str
    |> String.split()
    |> Enum.map(&String.to_charlist/1)
    |> Enum.zip_with(&Function.identity/1)
    |> Enum.map(&Enum.count(&1, fn char -> char == ?# end))
  end)

keys =
  keys
  |> Enum.map(fn str ->
    str
    |> String.split()
    |> Enum.map(&String.to_charlist/1)
    |> Enum.zip_with(&Function.identity/1)
    |> Enum.map(&Enum.count(&1, fn char -> char == ?# end))
  end)

for lock <- locks,
    key <- keys,
    zipped = Enum.zip_with(lock, key, fn n1, n2 -> n1 + n2 end),
    Enum.all?(zipped, &amp; &amp;1 <= 7),
    reduce: 0,
    do: (count -> count + 1)