c/aoc-2024
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Cleanup

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Christian
2024-12-09 11:14:11 +01:00
parent 24e925c27d
commit eee695007d
1 changed files with 22 additions and 25 deletions
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43
aoc/src/dev/ctsk/aoc/days/Day09.scala
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@@ -1,42 +1,39 @@
package dev.ctsk.aoc.days package dev.ctsk.aoc.days
import dev.ctsk.aoc._ import dev.ctsk.aoc.*
import scala.collection.mutable.PriorityQueue
import scala.math.Ordered.orderingToOrdered
import scala.annotation.tailrec import scala.annotation.tailrec
import scala.collection.mutable
object Day09 extends Solver(9): object Day09 extends Solver(9):
implicit def ord: Ordering[Record] = Ordering.by(-_.offset) implicit def ord: Ordering[Record] = Ordering.by(-1 * _.offset)
case class Record(offset: Int, size: Int, id: Int): case class Record(offset: Int, size: Int, id: Int):
def checksum: Long = id.toLong * (size * offset + size * (size - 1) / 2) def checksum: Long = id.toLong * (size * offset + size * (size - 1) / 2)
case class GapMap( case class GapMap(data: Map[Int, mutable.PriorityQueue[Record]]):
data: Map[Int, PriorityQueue[Record]]
):
def relocate(record: Record): Record = def relocate(record: Record): Record =
val bucket = data.view val bucket = data.view
.filter((gapSize, gaps) => gapSize >= record.size && gaps.nonEmpty) .filter((gapSize, gaps) => gapSize >= record.size && gaps.nonEmpty)
.minByOption(_._2.head.offset) .maxByOption(_._2.head)
bucket match bucket match
case None => record case None => record
case Some((gapSize, gaps)) => case Some((gapSize, gaps)) =>
val gap = gaps.dequeue() val gap = gaps.dequeue()
if gap.offset >= record.offset then return record if gap.offset >= record.offset then return record
val remaining = gapSize - record.size val rest = gapSize - record.size
if remaining > 0 then if rest > 0 then
data(remaining) data(rest).enqueue(Record(gap.offset + record.size, rest, -1))
.enqueue(Record(gap.offset + record.size, remaining, gap.id))
Record(gap.offset, record.size, record.id) Record(gap.offset, record.size, record.id)
def part1(input: Array[Int]): Long = def part1(input: Array[Int]): Long =
val materialized = input.zipWithIndex.flatMap((x, i) => val materialized = input.zipWithIndex.flatMap((x, i) =>
if i % 2 == 0 then Iterator.fill(x.toInt)(i / 2) if i % 2 == 0
else Iterator.fill(x.toInt)(-1) then Iterator.fill(x)(i / 2)
else Iterator.fill(x)(-1)
) )
@tailrec def compact(l: Int = 0, r: Int = materialized.length - 1): Unit = @tailrec
def compact(l: Int = 0, r: Int = materialized.length - 1): Unit =
if l >= r then return () if l >= r then return ()
if materialized(l) != -1 then return compact(l + 1, r) if materialized(l) != -1 then return compact(l + 1, r)
if materialized(r) == -1 then return compact(l, r - 1) if materialized(r) == -1 then return compact(l, r - 1)
@@ -48,19 +45,19 @@ object Day09 extends Solver(9):
def part2(input: Array[Int]): Long = def part2(input: Array[Int]): Long =
val offsets = input.scanLeft(0)(_ + _).toArray val offsets = input.scanLeft(0)(_ + _).toArray
val records =
input.zipWithIndex.zip(offsets).map { case ((value, index), offset) => val (gaps, files) = input.zip(offsets).zipWithIndex.partitionMap {
case ((value, offset), index) =>
if index % 2 == 0 if index % 2 == 0
then Record(offset, value, index / 2) then Right(Record(offset, value, index / 2))
else Record(offset, value, -1) else Left(Record(offset, value, -1))
} }
val (gaps, files) = records.partition(_.id == -1)
val gapMap = GapMap( val gapMap = GapMap(
gaps.groupBy(_.size).mapValues(PriorityQueue.from(_)).toMap gaps.groupBy(_.size).view.mapValues(mutable.PriorityQueue.from).toMap
) )
files.reverse.map(gapMap.relocate(_)).map(_.checksum).sum files.reverse.map(gapMap.relocate).map(_.checksum).sum
def run(input: os.ReadablePath): (Timings, Solution) = def run(input: os.ReadablePath): (Timings, Solution) =
val disk = os.read.lines(input)(0).map(_.asDigit).toArray val disk = os.read.lines(input)(0).map(_.asDigit).toArray