day2

Section

Mix.install([:kino])

input = Kino.Input.textarea("input file: ")

input = Kino.Input.read(input)

is_in_range = fn x, [a, b] -> x >= a and x <= b end
xor = &((&1 and not &2) or (not &1 and &2))

chunks =
  input
  |> String.split([" ", "\n"])
  |> Enum.map(&String.replace(&1, ":", ""))
  |> Enum.map_every(3, &(&1 |> String.split("-") |> Enum.map(fn x -> String.to_integer(x) end)))
  |> Enum.chunk_every(3)

part_1 =
  chunks
  |> Enum.filter(fn [nums, let, password] ->
    String.graphemes(password) |> Enum.count(&(&1 == let)) |> is_in_range.(nums)
  end)
  |> Enum.count()
  |> IO.puts()

part2 =
  chunks
  |> Enum.filter(fn [[n1, n2], let, password] ->
    xor.(String.at(password, n1 - 1) == let, String.at(password, n2 - 1) == let)
  end)
  |> Enum.count()
  |> IO.puts()