fun main() {
    fun part1(stacks: List<ArrayDeque<Char>>, steps: List<Step>): String {
        steps.map { step -> repeat(step.quantity) { stacks[step.target].addFirst(stacks[step.source].removeFirst()) } }
        return stacks.map { it.first() }.joinToString(separator = "")
    }

    fun part2(stacks: List<ArrayDeque<Char>>, steps: List<Step>): String {
        steps.map { step ->
            stacks[step.source].subList(0, step.quantity).asReversed()
                .map { stacks[step.target].addFirst(it) }
                .map { stacks[step.source].removeFirst() }
        }
        return stacks.map { it.first() }.joinToString(separator = "")
    }

    val input = readInput("day05")
    val numberOfStacks = input.dropWhile { it.contains("[") }.first().split(" ").filter { it.isNotBlank() }.maxOf { it.toInt() }
    val stacks = List(numberOfStacks) { ArrayDeque<Char>() }
    val steps = mutableListOf<Step>()

    input.filter { it.contains("[") }
        .map { line ->
            line
                .mapIndexed { index, char -> if (char.isLetter()) stacks[index / 4].addLast(line[index]) }
        }

    input.filter { it.contains("move") }.map { steps.add(Step.of(it)) }

    println(part1(stacks.map { ArrayDeque(it) }.toList(), steps))
    println(part2(stacks, steps))
}

data class Step(val quantity: Int, val source: Int, val target: Int) {
    companion object {
        fun of(line: String): Step {
            return line.split(" ").filterIndexed { index, _ -> index % 2 == 1 }.map { it.toInt() }.let { Step(it[0], it[1] - 1, it[2] - 1) }
        }
    }
}







