Advent of Code 2015 Day 19 Part 2

Mix.install([
  {:kino_aoc, "~> 0.1"}
])

Get Inputs

{:ok, puzzle_input} =
  KinoAOC.download_puzzle("2015", "19", System.fetch_env!("LB_SESSION"))

My answer

molecules =
  puzzle_input
  |> String.split("\n")
  |> Enum.reverse()
  |> hd()

count_str = fn molecules, str ->
  Regex.scan(~r/#{str}/, molecules)
  |> length()
end

count_str.("abcxxabcyy", "abc")

Regex.scan(~r/[A-Z]/, molecules)
|> length()
|> Kernel.-(count_str.(molecules, "Rn"))
|> Kernel.-(count_str.(molecules, "Ar"))
|> Kernel.-(2 * count_str.(molecules, "Y"))
|> Kernel.-(1)