2021 Day2 - rewrite

    @Test
    fun `Part 1 and 2`() {
        val submarine = Submarine()
        data.split("\n")
            .forEach { submarine.dive(it) }
        println("Part 1: " + submarine.part1())
        println("Part 2: " + submarine.part2())
    }

    private class Submarine {
        private var aim = 0
        private var position = 0
        private var depth = 0

        fun dive(instruction: String) {
            val (command, value) = instruction.split(" ")
            when(command) {
                "forward" -> {
                    position += value.toInt()
                    depth += aim * value.toInt()
                }
                "up" -> aim -= value.toInt()
                "down" -> aim += value.toInt()
            }
        }

        fun part1() = aim * position
        fun part2() = depth * position
    }