Advent of Code 2023 Day 4 Part 1

Mix.install([
  {:kino_aoc, "~> 0.1.5"}
])

Get Inputs

{:ok, puzzle_input} =
  KinoAOC.download_puzzle("2023", "4", System.fetch_env!("LB_SESSION"))

My answer

defmodule Resolver do
  def parse(input) do
    input
    |> String.split("\n")
    |> Enum.map(fn line ->
      [_, card] = String.split(line, ":")
      [winning_card, my_card] = String.split(card, "|")

      %{
        winning_card: parse_card(winning_card),
        my_card: parse_card(my_card)
      }
    end)
  end

  defp parse_card(card) do
    card
    |> String.split(" ")
    |> Enum.filter(fn value -> value != "" end)
    |> Enum.map(fn value -> String.to_integer(value) end)
  end

  def resolve(games) do
    games
    |> Enum.map(fn %{winning_card: winning_card, my_card: my_card} ->
      winning_card
      |> Enum.count(fn winnig_number ->
        Enum.member?(my_card, winnig_number)
      end)
      |> get_point()
    end)
    |> Enum.sum()
  end

  defp get_point(0), do: 0
  defp get_point(1), do: 1

  defp get_point(nuber_of_matches) do
    0..(nuber_of_matches - 2)
    |> Enum.map(&Integer.pow(2, &1))
    |> Enum.sum()
    |> Kernel.+(1)
  end
end

games =
  """
  Card 1: 41 48 83 86 17 | 83 86  6 31 17  9 48 53
  Card 2: 13 32 20 16 61 | 61 30 68 82 17 32 24 19
  Card 3:  1 21 53 59 44 | 69 82 63 72 16 21 14  1
  Card 4: 41 92 73 84 69 | 59 84 76 51 58  5 54 83
  Card 5: 87 83 26 28 32 | 88 30 70 12 93 22 82 36
  Card 6: 31 18 13 56 72 | 74 77 10 23 35 67 36 11
  """
  |> String.slice(0..-2)
  |> Resolver.parse()

Resolver.resolve(games)

games = Resolver.parse(puzzle_input)

Resolver.resolve(games)