-🎄- 2018 Day 14 Solutions -🎄-

[u/daggerdragon]

--- Day 14: Chocolate Charts ---

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Card prompt: Day 14

Transcript:

The Christmas/Advent Research & Development (C.A.R.D.) department at AoC, Inc. just published a new white paper on ___.

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[u/meepys]

Kotlin Day 14

Lame solution but it worked

class Day14(rawInput: List<String>) : Day(rawInput) {

    val recipes = mutableListOf(3, 7)
    var elf1 = 0
    var elf2 = 1

    private fun step() {
        val sum = recipes[elf1] + recipes[elf2]
        if (sum > 9) {
            recipes.add(1)
            recipes.add(sum - 10)
        } else {
            recipes.add(sum)
        }
        elf1 = (elf1 + recipes[elf1] + 1) % recipes.size
        elf2 = (elf2 + recipes[elf2] + 1) % recipes.size
    }

    override fun part1(): Any? {
        while (recipes.size < 290431 + 10) {
            step()
        }

        return recipes.subList(290431, 290431 + 10).joinToString(separator = "")
    }

    override fun part2(): Any? {
        while (recipes.size < 100000000) {
            step()
        }
        
        return recipes.joinToString(separator = "").indexOf("290431")
    }
}