Advent of Code 2022 - Day 4

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

Input

test_input =
  """
  2-4,6-8
  2-3,4-5
  5-7,7-9
  2-8,3-7
  6-6,4-6
  2-6,4-8
  """
  |> String.trim()

{:ok, puzzle_input} = KinoAOC.download_puzzle("2022", "4", System.fetch_env!("LB_AOC_SESSION"))

input_field =
  Kino.Input.select("input", [
    {test_input, "test_input"},
    {puzzle_input, "puzzle_input"}
  ])

Parsing

parsed =
  input_field
  |> Kino.Input.read()
  |> String.split("\n", trim: true)
  |> Enum.flat_map(&String.split(&1, ~r/[-,]/))
  |> Enum.map(&String.to_integer/1)
  |> Enum.chunk_every(4)

Part 1

Enum.count(parsed, fn [ax, ay, bx, by] -> (ax <= bx and ay >= by) or (ax >= bx and ay <= by) end)

Part 2

Enum.count(parsed, fn [ax, ay, bx, by] -> bx <= ay and by >= ax end)