Day 02

Mix.install([{:kino, "~> 0.6.2"}])

Input

input = Kino.Input.textarea("Please paste your")

Part 1

input
|> Kino.Input.read()
|> String.split("\n", trim: true)
|> Enum.reduce({_depth = 0, _position = 0}, fn
  "forward " <> number, {depth, position} -> {depth, String.to_integer(number) + position}
  "down " <> number, {depth, position} -> {depth + String.to_integer(number), position}
  "up " <> number, {depth, position} -> {depth + -String.to_integer(number), position}
end)
|> then(fn {depth, position} -> depth * position end)

Part 2

input
|> Kino.Input.read()
|> String.split("\n", trim: true)
|> Enum.reduce({_depth = 0, _position = 0, _aim = 0}, fn
  "forward " <> number, {depth, position, aim} ->
    number = String.to_integer(number)
    {depth + aim * number, position + number, aim}

  "down " <> number, {depth, position, aim} ->
    {depth, position, aim + String.to_integer(number)}

  "up " <> number, {depth, position, aim} ->
    {depth, position, aim - String.to_integer(number)}
end)
|> then(fn {depth, position, _aim} -> depth * position end)