Advent of Code 2024 - Day 3

Learning Resources Coding Challenges
,
6

Hey!

This is my solution for Day 03.

Part 1

Regex.scan(~r/mul\((\d+),(\d+)\)/, puzzle_input, capture: :all_but_first)
|> Enum.map(fn [a, b] ->
  String.to_integer(a) * String.to_integer(b)
end)
|> Enum.sum()

Part 2

Regex.scan(~r/mul\((-?\d+),(-?\d+)\)|do(?:n't)?\(\)/, puzzle_input)
|> Enum.reduce({0, :enabled}, fn
  ["don't()"], {count, _status} ->
    {count, :disabled}

  ["do()"], {count, _status} ->
    {count, :enabled}

  [_text, a, b], {count, :enabled} ->
    result = String.to_integer(a) * String.to_integer(b)

    {result + count, :enabled}

  [_text, _a, _b], {count, :disabled} ->
    {count, :disabled}
end)
|> elem(0)