Day 1: Historian Hysteria

Mix.install([:kino])

Section

input = Kino.Input.textarea("Input", monospace: true)

{l1, l2} =
  input
  |> Kino.Input.read()
  |> String.split([" ", "\n"], trim: true)
  |> Enum.map(&String.to_integer/1)
  |> Enum.chunk_every(2)
  |> Enum.map(&List.to_tuple/1)
  |> Enum.unzip()

defmodule LocationID do
  def distance(l1, l2) do
    Enum.zip(Enum.sort(l1), Enum.sort(l2))
    |> Enum.map(fn {a, b} -> abs(a - b) end)
    |> Enum.sum()
  end

  def similarity(l1, l2) do
    f = Enum.frequencies(l2)

    l1
    |> Enum.map(&similarity_score(&1, f))
    |> Enum.sum()
  end

  defp similarity_score(i, f) do
    i * Map.get(f, i, 0)
  end
end

LocationID.distance(l1, l2)

LocationID.similarity(l1, l2)