Day 1

Setup

Mix.install([:kino])

input =
  Kino.Input.textarea("Paste input here",
    default: """
    1000
    2000
    3000

    4000

    5000
    6000

    7000
    8000
    9000

    10000
    """
  )

snack_totals =
  input
  |> Kino.Input.read()
  |> String.split("\n\n", trim: true)
  |> Stream.map(fn snacks ->
    snacks
    |> String.split("\n", trim: true)
    |> Stream.map(&String.to_integer/1)
    |> Enum.sum()
  end)

Part 1

Enum.max(snack_totals)

Part 2

snack_totals
|> Enum.sort(:desc)
|> Enum.take(3)
|> IO.inspect()
|> Enum.sum()

# alternative approach
# snack_totals
# |> Enum.reduce([], fn 
# el, [] -> [el]
# el, [a] -> [a, el]
# el, [a, b] -> Enum.sort([a,b,el], :desc)
# el, [a,b,c] when el > a -> ([el,b,c])
# el, [a,b,c] when el > b -> ([a,el,c])
# el, [a,b,c] when el > c -> ([a,b,el])
# _, els -> els
# end)