day2

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

Section

input = Kino.Input.textarea("Input")

qs =
  String.split(
    "Game 1: 3 blue, 4 red; 1 red, 2 green, 6 blue; 2 green
Game 2: 1 blue, 2 green; 3 green, 4 blue, 1 red; 1 green, 1 blue
Game 3: 8 green, 6 blue, 20 red; 5 blue, 4 red, 13 green; 5 green, 1 red
Game 4: 1 green, 3 red, 6 blue; 3 green, 6 red; 3 green, 15 blue, 14 red
Game 5: 6 red, 1 blue, 3 green; 2 blue, 1 red, 2 green",
    "\n"
  )

qs = String.split(Kino.Input.read(input), "\n")

defmodule My do
  def parse(s) do
    rounds = String.split(List.last(String.split(s, ":")), ";")
    {id, _} = Integer.parse(List.last(String.split(List.first(String.split(s, ":")))))

    case Enum.all?(rounds, &My.valid?(&1)) do
      true -> id
      false -> 0
    end
  end

  def valid?(s) do
    red = get_color_num(s, "red")
    green = get_color_num(s, "green")
    blue = get_color_num(s, "blue")
    red <= 12 and green <= 13 and blue <= 14
  end

  def get_color_num(s, color) do
    case String.contains?(s, color) do
      true -> elem(Integer.parse(List.last(String.split(List.first(String.split(s, color))))), 0)
      false -> 0
    end
  end
end

Enum.reduce(qs, 0, fn x, acc -> acc + My.parse(x) end)

qs =
  String.split(
    "Game 1: 3 blue, 4 red; 1 red, 2 green, 6 blue; 2 green
Game 2: 1 blue, 2 green; 3 green, 4 blue, 1 red; 1 green, 1 blue
Game 3: 8 green, 6 blue, 20 red; 5 blue, 4 red, 13 green; 5 green, 1 red
Game 4: 1 green, 3 red, 6 blue; 3 green, 6 red; 3 green, 15 blue, 14 red
Game 5: 6 red, 1 blue, 3 green; 2 blue, 1 red, 2 green",
    "\n"
  )

qs = String.split(Kino.Input.read(input), "\n")

defmodule My2 do
  def parse(s) do
    [_, id | rounds] = Enum.filter(Regex.split(~r{[:,\s;]}, s), fn x -> x != "" end)
    max_count = get_max_count(rounds, %{"red" => 0, "blue" => 0, "green" => 0})
    max_count["red"] * max_count["blue"] * max_count["green"]
  end

  def get_max_count([], max_count), do: max_count

  def get_max_count([count_str, color | rest], max_count) do
    count = String.to_integer(count_str)
    max_count = %{max_count | color => max(max_count[color], count)}
    get_max_count(rest, max_count)
  end
end

Enum.reduce(qs, 0, fn x, acc -> acc + My2.parse(x) end)