2022 - day 6

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

Section

input_1 = Kino.Input.textarea("")

input = Kino.Input.textarea("")

defmodule Part1 do
  defguardp is_all_uniq(a, b, c, d) when a not in [b, c, d] and b not in [c, d] and c != d

  def solve(input) do
    input
    |> String.graphemes()
    |> Enum.reduce_while({{}, 0}, fn
      _c, {{a1, a2, a3, a4}, cnt} when is_all_uniq(a1, a2, a3, a4) ->
        {:halt, cnt}

      c, {{_, _, _, _} = window, cnt} ->
        new_window =
          window
          |> Tuple.delete_at(0)
          |> Tuple.append(c)

        {:cont, {new_window, cnt + 1}}

      c, {not_enough_window, cnt} ->
        {:cont,
         {not_enough_window
          |> Tuple.append(c), cnt + 1}}
    end)
  end
end

input
|> Kino.Input.read()
|> Part1.solve()

defmodule Part2 do
  def solve(input) do
    input
    |> String.graphemes()
    |> Stream.chunk_every(14, 1)
    |> Enum.find_index(&all_uniq?/1)
    |> Kernel.+(14)
  end

  defp all_uniq?(list) do
    Enum.uniq(list) == list
  end
end

input
|> Kino.Input.read()
|> Part2.solve()