Day 3: Rucksack Reorganization

Mix.install([{:kino, "~> 0.7.0"}])

Day 3

• Puzzle: https://adventofcode.com/2022/day/3
• Input: https://adventofcode.com/2022/day/3/input

sample_input = Kino.Input.textarea("Paste Sample Input")

real_input = Kino.Input.textarea("Paste Real Input")

parse_rucksacks = fn input ->
  input
  |> Kino.Input.read()
  |> String.split()
  |> Enum.map(&String.to_charlist/1)
  |> Enum.map(&Enum.chunk_every(&1, div(length(&1), 2)))
  |> dbg()
end

char_score = fn
  char when char < ?a -> char - ?A + 27
  char -> char - ?a + 1
end

rucksack_score = fn [first, second] ->
  first
  |> MapSet.new()
  |> MapSet.intersection(MapSet.new(second))
  |> MapSet.to_list()
  |> List.first()
  |> char_score.()
end

sample_input |> parse_rucksacks.() |> Enum.map(rucksack_score) |> Enum.sum()

real_input |> parse_rucksacks.() |> Enum.map(rucksack_score) |> Enum.sum()

parse_rucksacks_two = fn input ->
  input
  |> Kino.Input.read()
  |> String.split()
  |> Enum.map(fn line -> line |> String.to_charlist() |> MapSet.new() end)
end

group_total_sum = fn rucksacks ->
  rucksacks
  |> Enum.chunk_every(3)
  |> Enum.map(fn [one, two, three] ->
    one
    |> MapSet.intersection(two)
    |> MapSet.intersection(three)
    |> Enum.to_list()
    |> List.first()
    |> char_score.()
  end)
  |> Enum.sum()
end

sample_input |> parse_rucksacks_two.() |> group_total_sum.()

real_input |> parse_rucksacks_two.() |> group_total_sum.()