Advent of Code 2025 - Day 5

Learning Resources Coding Challenges
,
6

That is why I created RangeSet:

Parse

[fresh, ingridients] = String.split(puzzle_input, "\n\n")

fresh =
  fresh
  |> String.split()
  |> Enum.map(fn range ->
    [a, b] = range |> String.split("-") |> Enum.map(&String.to_integer/1)

    a..b//1
  end)
  |> RangeSet.new()

ingridients =
  ingridients
  |> String.split()
  |> Enum.map(&String.to_integer/1)

Part 1

Enum.count(ingridients, & &1 in fresh)

Part 2

Enum.count(fresh)