Advent of code day 03

Mix.install([
  {:kino, "~> 0.5.0"}
])

Setup input

example = Kino.Input.textarea("Please paste your input example:")

input = Kino.Input.textarea("Please paste your real input:")

Part 01

defmodule Solver do
  def parse(line) do
    parse(line, [])
  end

  for i <- [8, 16, 24], j <- [8, 16, 24] do
    defp parse(
           <<"mul("::binary, d1::integer-size(unquote(i)), ","::binary,
             d2::integer-size(unquote(j)), ")"::binary, rest::binary>>,
           state
         ) do
      new_value =
        String.to_integer(:binary.encode_unsigned(d1)) *
          String.to_integer(:binary.encode_unsigned(d2))

      parse(rest, [new_value | state])
    end
  end

  ## end 
  defp parse(<<_e::binary-size(1), rest::binary>>, state), do: parse(rest, state)
  defp parse(<<>>, state), do: Enum.sum(state)
end

parsed =
  example
  |> Kino.Input.read()
  |> Solver.parse

Part 02

defmodule Solver2 do
  def parse(line) do
    parse(line, [])
  end

  defp parse(<<"don't()"::binary, rest::binary>>, [:dont | _] = state) do
    parse(rest, state)
  end

  defp parse(<<"don't()"::binary, rest::binary>>, state) do
    state = [:dont | state]
    parse(rest, state)
  end

  defp parse(<<"do()"::binary, rest::binary>>, [:dont | tail ] = _state) do
    state =  tail
    parse(rest, state)
  end

  defp parse(<<_e::binary-size(1), rest::binary>>, [:dont | _tail] = state) do
    parse(rest, state)
  end

  for i <- [8, 16, 24], j <- [8, 16, 24] do
    defp parse(
           <<"mul("::binary, d1::integer-size(unquote(i)), ","::binary,
             d2::integer-size(unquote(j)), ")"::binary, rest::binary>>,
           state
         ) do
      new_value =
        String.to_integer(:binary.encode_unsigned(d1)) *
          String.to_integer(:binary.encode_unsigned(d2))
      parse(rest, [new_value | state])
    end
  end

  ## end 
  defp parse(<<_e::binary-size(1), rest::binary>>, state) do
    parse(rest, state)
  end

  defp parse(<<>>, [:dont, tail ]), do:  Enum.sum(tail)
  defp parse(<<>>, state), do:  Enum.sum(state)
end

parsed =
  example
  |> Kino.Input.read()
  |> Solver2.parse()