AoC 2023 D02

Mix.install([:kino])

defmodule Utils do
  def split(line, sep \\ "") do
    String.split(line, sep, trim: true)
  end

  def split_all_lines(text, sep \\ "") do
    text
    |> String.split("\n", trim: true)
    |> Enum.map(&split(&1, sep))
  end

  def to_numbers(number) when is_binary(number) do
    String.to_integer(number)
  end

  def to_numbers(numbers) when is_list(numbers) do
    Enum.map(numbers, &to_numbers/1)
  end

  def to_matrix(text, sep \\ "") do
    text
    |> split_all_lines(sep)
    |> then(fn data ->
      for {row, r} <- Enum.with_index(data), {col, c} <- Enum.with_index(row) do
        {{r, c}, col}
      end
    end)
    |> Map.new()
  end
end

Setup

import Utils

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

text = Kino.Input.read(input)

data =
  split(text, "\n")
  |> Enum.map(fn line ->
    ["Game " <> id | sets] = split(line, [":", ";"])

    {String.to_integer(id),
     sets
     |> Enum.map(fn set ->
       set
       |> split([" ", ","])
       |> Enum.chunk_every(2)
       |> Enum.map(fn [count, color] -> {color, String.to_integer(count)} end)
       |> Map.new()
     end)}
  end)

P1

defmodule P1 do
  def solve(data) do
    data
    |> Enum.filter(fn {_id, sets} ->
      Enum.all?(
        sets,
        &amp;(Map.get(&amp;1, "red", 0) <= 12 and Map.get(&amp;1, "green", 0) <= 13 and
            Map.get(&amp;1, "blue", 0) <= 14)
      )
    end)
    |> Enum.map(fn {id, _} -> id end)
    |> Enum.sum()
  end
end

P1.solve(data)

P2

defmodule P2 do
  def solve(data) do
    data
    |> Enum.map(fn {_id, sets} ->
      sets
      |> Enum.reduce(&Map.merge(&1, &2, fn _k, v1, v2 -> max(v1, v2) end))
      |> Map.values()
      |> Enum.product()
    end)
    |> Enum.sum()
  end
end

P2.solve(data)