Day 6

Mix.install([
  {:kino, "~> 0.8.0"}
])

Section

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

defmodule AOC do
  def has_duplicates?(list) do
    list
    |> Enum.reduce_while([], fn x, acc ->
      if x in acc, do: {:halt, false}, else: {:cont, [x | acc]}
    end)
    |> is_boolean()
  end

  def run(input, size) do
    input
    |> String.graphemes()
    |> Enum.with_index(1)
    |> Enum.reduce_while([], fn {code, index}, acc ->
      cond do
        length(acc) <= size ->
          {:cont, acc ++ [code]}

        true ->
          case has_duplicates?([code | acc]) do
            false -> {:halt, index}
            true -> {:cont, List.pop_at(acc, 0) |> elem(1) |> Kernel.++([code])}
          end
      end

      # :cont, acc + x}, else: {:halt, acc}
    end)
  end
end

res_one = AOC.run(Kino.Input.read(input), 2)
res_two = AOC.run(Kino.Input.read(input), 12)

IO.puts("
  Solution part one: #{res_one}
  Solution part two: #{res_two}
")

ExUnit.start()

defmodule Test do
  use ExUnit.Case

  test "part one" do
    assert AOC.run("mjqjpqmgbljsphdztnvjfqwrcgsmlb", 2) == 7
    assert AOC.run("bvwbjplbgvbhsrlpgdmjqwftvncz", 2) == 5
    assert AOC.run("nppdvjthqldpwncqszvftbrmjlhg", 2) == 6
    assert AOC.run("nznrnfrfntjfmvfwmzdfjlvtqnbhcprsg", 2) == 10
    assert AOC.run("zcfzfwzzqfrljwzlrfnpqdbhtmscgvjw", 2) == 11
  end

  test "part dois" do
    assert AOC.run("mjqjpqmgbljsphdztnvjfqwrcgsmlb", 12) == 19
    assert AOC.run("bvwbjplbgvbhsrlpgdmjqwftvncz", 12) == 23
    assert AOC.run("nppdvjthqldpwncqszvftbrmjlhg", 12) == 23
    assert AOC.run("nznrnfrfntjfmvfwmzdfjlvtqnbhcprsg", 12) == 29
    assert AOC.run("zcfzfwzzqfrljwzlrfnpqdbhtmscgvjw", 12) == 26
  end
end

ExUnit.run()