Day 2

Mix.install([
  {:req, "~> 0.4.5"},
  {:kino, "~> 0.11.3"}
])

Input

session = System.fetch_env!("LB_AOC_SESSION")

input =
  Req.get!(
    "https://adventofcode.com/2023/day/2/input",
    headers: [{"Cookie", ~s"session=#{session}"}]
  ).body

Kino.Text.new(input, terminal: true)

Part 1

defmodule Part1 do
  def answer(text, %{} = bag) do
    text
    |> String.trim_trailing()
    |> String.splitter("\n")
    |> Enum.map(fn line ->
      Regex.scan(~r/(\d+) (\w+)/, line)
      |> Enum.map(fn [_, n, color] ->
        {String.to_integer(n), color}
      end)
      |> Enum.reduce(%{}, fn {n, color}, acc ->
        Map.put(acc, color, max(n, Map.get(acc, color, 0)))
      end)
    end)
    |> Enum.with_index(1)
    |> Enum.filter(fn {set, _} ->
      Enum.all?(set, fn {key, value} -> value <= bag[key] end)
    end)
    |> Enum.map(&amp;elem(&amp;1, 1))
    |> Enum.sum()
  end
end

bag = %{"red" => 12, "green" => 13, "blue" => 14}
Part1.answer(input, bag)

Part 2

defmodule Part2 do
  def answer(text) do
    text
    |> String.trim_trailing()
    |> String.splitter("\n")
    |> Enum.map(fn line ->
      Regex.scan(~r/(\d+) (\w+)/, line)
      |> Enum.map(fn [_, n, color] ->
        {String.to_integer(n), color}
      end)
      |> Enum.reduce(%{}, fn {n, color}, acc ->
        Map.put(acc, color, max(n, Map.get(acc, color, 0)))
      end)
      |> Map.values()
      |> Enum.product()
    end)
    |> Enum.sum()
  end
end

Part2.answer(input)