Day 04

Mix.install([
  {:kino, "~> 0.7.0"}
])

example_input =
  Kino.Input.textarea("example input:")
  |> Kino.render()

real_input = Kino.Input.textarea("real input:")

Common

parse = fn input ->
  input
  |> Kino.Input.read()
  |> String.split(["-", ",", "\n"])
  |> Enum.map(&String.to_integer/1)
  |> Enum.chunk_every(4)
  |> Enum.map(fn [a, b, c, d] -> {Range.new(a, b), Range.new(c, d)} end)
end

Part 1

contained? = fn {a, b} ->
  (a.first in b and a.last in b) or (b.first in a and b.last in a)
end

real_input
|> then(parse)
|> Enum.filter(contained?)
|> length()

Part 2

overlaps? = fn {a, b} -> not Range.disjoint?(a, b) end

real_input
|> then(parse)
|> Enum.filter(overlaps?)
|> length()