70 lines
1.7 KiB
Scala
70 lines
1.7 KiB
Scala
|
package aoc.day18
|
||
|
|
|
||
|
|
import aoc._
|
||
|
|
import aoc.direction._
|
||
|
|
import Dir._
|
||
|
|
import scala.collection.SortedMap
|
||
|
|
import scala.collection.mutable
|
||
|
|
|
||
|
|
case class Dig(dir: Dir, count: Int, color: String):
|
||
|
|
lazy val part2 = Parser.parse(Parser.digHex, color).get
|
||
|
|
|
||
|
|
def apply(x: Long, y: Long) = dir.long(x, y, count)
|
||
|
|
|
||
|
|
object Parser extends CommonParser with DirParser:
|
||
|
|
val dig = dir ~ num ~ "(#" ~ """[0-9a-f]{6}""".r ~ ")" ^^ { case dir ~ num ~ _ ~ color ~ _ =>
|
||
|
|
Dig(dir, num, color)
|
||
|
|
}
|
||
|
|
|
||
|
|
val hexDigit = """[0-9a-f]""".r ^^ {
|
||
|
|
case c if c.charAt(0).isDigit => c.charAt(0) - '0'
|
||
|
|
case c => c.charAt(0) - 'a' + 10
|
||
|
|
}
|
||
|
|
|
||
|
|
def hexNum(len: Int) = repN(len, hexDigit).map(_.foldLeft(0)(_ * 16 + _))
|
||
|
|
|
||
|
|
val toDir = Array(Right, Down, Left, Up)
|
||
|
|
val digHex = hexNum(5) ~ hexDigit ^^ { case num ~ dig => Dig(toDir(dig), num, "") }
|
||
|
|
|
||
|
|
def apply(s: String) = parse(dig, s).get
|
||
|
|
|
||
|
|
def instructions() = lines.map(Parser(_)).toSeq
|
||
|
|
|
||
|
|
def points(ins: Seq[Dig]) =
|
||
|
|
ins
|
||
|
|
.scanLeft((0L, 0L)) { case ((x, y), in) => in(x, y) }
|
||
|
|
.dropRight(1)
|
||
|
|
|
||
|
|
extension [T](ss: Seq[T]) def shiftLeft = ss.drop(1) ++ ss.take(1)
|
||
|
|
|
||
|
|
def area(pts: Seq[(Long, Long)]) = pts
|
||
|
|
.lazyZip(pts.shiftLeft)
|
||
|
|
.map { case ((ax, ay), (bx, by)) =>
|
||
|
|
(bx - ax) * (by + ay)
|
||
|
|
}
|
||
|
|
.sum
|
||
|
|
.abs
|
||
|
|
|
||
|
|
def circum(pts: Seq[(Long, Long)]) = pts
|
||
|
|
.lazyZip(pts.shiftLeft)
|
||
|
|
.map { case ((ax, ay), (bx, by)) =>
|
||
|
|
(bx - ax).abs + (by - ay).abs
|
||
|
|
}
|
||
|
|
.sum
|
||
|
|
|
||
|
|
def areaBlock(pts: Seq[(Long, Long)]) = (area(pts) + circum(pts)) / 2 + 1
|
||
|
|
|
||
|
|
def part1 =
|
||
|
|
val ins = instructions()
|
||
|
|
val pts = points(ins)
|
||
|
|
println(areaBlock(pts))
|
||
|
|
|
||
|
|
def part2 =
|
||
|
|
val ins = instructions().map(_.part2)
|
||
|
|
val pts = points(ins)
|
||
|
|
println(areaBlock(pts))
|
||
|
|
|
||
|
|
@main def Day18(part: Int) = part match
|
||
|
|
case 1 => part1
|
||
|
|
case 2 => part2
|