day_03.ex

defmodule AdventOfCode.Day03 do
  def part1(input) do
    Regex.scan(~r"mul\((\d+),(\d+)\)", input)
    |> Enum.map(fn [_, a, b] -> String.to_integer(a) * String.to_integer(b) end)
    |> Enum.sum()
  end

  def part2(input) do
    Regex.scan(~r"do\(\)(.+?)don't\(\)", "do()" <> String.trim(input) <> "don't()")
    |> Enum.map(fn [_, match] -> part1(match) end)
    |> Enum.sum()
  end
end