diff options
Diffstat (limited to 'src/Day16.kt')
| -rw-r--r-- | src/Day16.kt | 218 |
1 files changed, 112 insertions, 106 deletions
diff --git a/src/Day16.kt b/src/Day16.kt index f8b287c..d11219d 100644 --- a/src/Day16.kt +++ b/src/Day16.kt @@ -1,120 +1,123 @@ -import kotlin.collections.ArrayDeque - -sealed class Packet( - private val bits: Int, - protected val version: Int, -) { - class Literal( - bits: Int, - version: Int, - private val literalValue: Long, - ) : Packet(bits, version) { - override fun versionSum(): Int = version - - override val value: Long - get() = literalValue - } +object Day16 { + private sealed class Packet( + private val bits: Int, + protected val version: Int, + ) { + private class Literal( + bits: Int, + version: Int, + private val literalValue: Long, + ) : Packet(bits, version) { + override fun versionSum(): Int = version + + override val value: Long + get() = literalValue + } - class Operator( - bits: Int, - version: Int, - private val typeId: Int, - private val subpackets: List<Packet>, - ) : Packet(bits, version) { - override fun versionSum(): Int = version + subpackets.sumOf { it.versionSum() } - - override val value: Long - get() = when (typeId) { - 0 -> subpackets.sumOf { it.value } - 1 -> subpackets.fold(1) { acc, packet -> acc * packet.value } - 2 -> subpackets.minOf { it.value } - 3 -> subpackets.maxOf { it.value } - 5, 6, 7 -> { - val (first, second) = subpackets.map { it.value } - - if (when (typeId) { - 5 -> first > second - 6 -> first < second - 7 -> first == second - else -> false - }) { - 1 - } else { - 0 + private class Operator( + bits: Int, + version: Int, + private val typeId: Int, + private val subpackets: List<Packet>, + ) : Packet(bits, version) { + override fun versionSum(): Int = version + subpackets.sumOf { it.versionSum() } + + override val value: Long + get() = when (typeId) { + 0 -> subpackets.sumOf { it.value } + 1 -> subpackets.fold(1) { acc, packet -> acc * packet.value } + 2 -> subpackets.minOf { it.value } + 3 -> subpackets.maxOf { it.value } + 5, 6, 7 -> { + val (first, second) = subpackets.map { it.value } + + if (when (typeId) { + 5 -> first > second + 6 -> first < second + 7 -> first == second + else -> false + } + ) { + 1 + } else { + 0 + } } + + else -> throw IllegalStateException("Illegal packet type id.") } - else -> throw IllegalStateException("Illegal packet type id.") - } - } + } - abstract fun versionSum(): Int + abstract fun versionSum(): Int - abstract val value: Long + abstract val value: Long - companion object { - fun parse(bitQueue: ArrayDeque<Char>): Packet { - var packetBits = 0 + companion object { + fun parse(bitQueue: ArrayDeque<Char>): Packet { + var packetBits = 0 - fun takeBits(n: Int): Int { - packetBits += n - return (0 until n) - .joinToString("") { bitQueue.removeFirst().toString() } - .toInt(2) - } + fun takeBits(n: Int): Int { + packetBits += n + return (0 until n) + .joinToString("") { bitQueue.removeFirst().toString() } + .toInt(2) + } - val version = takeBits(3) + val version = takeBits(3) - when (val typeId = takeBits(3)) { - 4 -> { // Literal packet - var literalValue = 0L - while (true) { - val groupHeader = takeBits(1) - val groupValue = takeBits(4) + when (val typeId = takeBits(3)) { + 4 -> { // Literal packet + var literalValue = 0L + while (true) { + val groupHeader = takeBits(1) + val groupValue = takeBits(4) - literalValue = (literalValue shl 4) + groupValue + literalValue = (literalValue shl 4) + groupValue - if (groupHeader == 0) { - break + if (groupHeader == 0) { + break + } } + + return Literal(packetBits, version, literalValue) } - return Literal(packetBits, version, literalValue) - } - else -> { // Operator packet - val subpackets = mutableListOf<Packet>() - - when (takeBits(1)) { - 0 -> { - val subpacketLength = takeBits(15) - - var currentSubpacketLength = 0 - while (currentSubpacketLength < subpacketLength) { - val subpacket = parse(bitQueue) - currentSubpacketLength += subpacket.bits - subpackets.add(subpacket) + else -> { // Operator packet + val subpackets = mutableListOf<Packet>() + + when (takeBits(1)) { + 0 -> { + val subpacketLength = takeBits(15) + + var currentSubpacketLength = 0 + while (currentSubpacketLength < subpacketLength) { + val subpacket = parse(bitQueue) + currentSubpacketLength += subpacket.bits + subpackets.add(subpacket) + } } - } - 1 -> { - val subpacketCount = takeBits(11) - repeat(subpacketCount) { - subpackets.add(parse(bitQueue)) + 1 -> { + val subpacketCount = takeBits(11) + + repeat(subpacketCount) { + subpackets.add(parse(bitQueue)) + } } + + else -> throw IllegalStateException("Illegal length type id.") } - else -> throw IllegalStateException("Illegal length type id.") - } - packetBits += subpackets.sumOf { it.bits } + packetBits += subpackets.sumOf { it.bits } - return Operator(packetBits, version, typeId, subpackets) + return Operator(packetBits, version, typeId, subpackets) + } } } } } -} -fun main() { - fun parse(input: String): Packet { + private fun parse(input: String): Packet { val bitQueue = ArrayDeque( input .flatMap { @@ -133,23 +136,26 @@ fun main() { fun part1(input: String): Int = parse(input).versionSum() fun part2(input: String): Long = parse(input).value +} + - check(part1("8A004A801A8002F478") == 16) - check(part1("620080001611562C8802118E34") == 12) - check(part1("C0015000016115A2E0802F182340") == 23) - check(part1("A0016C880162017C3686B18A3D4780") == 31) +fun main() { + check(Day16.part1("8A004A801A8002F478") == 16) + check(Day16.part1("620080001611562C8802118E34") == 12) + check(Day16.part1("C0015000016115A2E0802F182340") == 23) + check(Day16.part1("A0016C880162017C3686B18A3D4780") == 31) - check(part2("C200B40A82") == 3L) - check(part2("04005AC33890") == 54L) - check(part2("880086C3E88112") == 7L) - check(part2("CE00C43D881120") == 9L) - check(part2("D8005AC2A8F0") == 1L) - check(part2("F600BC2D8F") == 0L) - check(part2("9C005AC2F8F0") == 0L) - check(part2("9C0141080250320F1802104A08") == 1L) + check(Day16.part2("C200B40A82") == 3L) + check(Day16.part2("04005AC33890") == 54L) + check(Day16.part2("880086C3E88112") == 7L) + check(Day16.part2("CE00C43D881120") == 9L) + check(Day16.part2("D8005AC2A8F0") == 1L) + check(Day16.part2("F600BC2D8F") == 0L) + check(Day16.part2("9C005AC2F8F0") == 0L) + check(Day16.part2("9C0141080250320F1802104A08") == 1L) val input = readInputAsString("Day16") - println(part1(input)) - println(part2(input)) + println(Day16.part1(input)) + println(Day16.part2(input)) } |