Advent of Code 2024 Day 3 Part 2

Mix.install([
  {:kino_aoc, "~> 0.1"}
])

Get Inputs

{:ok, puzzle_input} =
  KinoAOC.download_puzzle("2024", "3", System.fetch_env!("LB_SESSION"))

My answer

Regex.scan(~r/mul\(\d+,\d+\)|do[n't]*\(\)/, puzzle_input)

Regex.scan(~r/mul\(\d+,\d+\)|do[n't]*\(\)/, puzzle_input)
|> Enum.reduce({true, 0}, fn [instruction], {do_flag, acc} ->
  case {do_flag, instruction} do
    {_, "do()"} -> {true, acc}
    {_, "don't()"} -> {false, acc}
    {true, mul} ->
      product =
        Regex.scan(~r/\d+/, mul)
        |> Enum.map(fn [str] ->
          String.to_integer(str)
        end)
        |> Enum.product()

      {true, acc + product}
    _ ->
      {do_flag, acc}
  end
end)
|> elem(1)