Can definitely be tidied up and simplified, but still exploring different ways to solve a problem in Elixir
defmodule Aoc2024.Day3 do
def part_1(input) do
~r/mul\((\d{1,3}),(\d{1,3})\)/
|> Regex.scan(input, capture: :all_but_first)
|> Enum.reduce(0, fn [a, b], acc -> acc + (String.to_integer(a) * String.to_integer(b)) end)
end
def part_2(input) do
~r/mul\((\d{1,3}),(\d{1,3})\)|don't\(\)|do\(\)/
|> Regex.scan(input)
|> Enum.reduce({:enabled, 0}, fn row, acc ->
case process(row) do
:enabled ->
{:enabled, elem(acc, 1)}
:disabled ->
{:disabled, elem(acc, 1)}
x ->
case elem(acc, 0) do
:disabled ->
{:disabled, elem(acc, 1)}
:enabled ->
{:enabled, x + elem(acc, 1)}
end
end
end)
end
def process(row) when is_list(row) and length(row) == 1 do
case row do
["don't()"] ->
:disabled
["do()"] ->
:enabled
end
end
def process(row) when is_list(row) and length(row) == 3 do
[_ | rest] = row
rest
|> Enum.map(&String.to_integer/1)
|> Enum.product()
end
end
