aoc2023/Day2.scala
2023-12-02 15:31:39 +01:00

52 lines
1.4 KiB
Scala

//> using dep org.scala-lang.modules::scala-parser-combinators::2.3.0
import aoc._
import scala.util.parsing.combinator._
case class Hand(red: Int, green: Int, blue: Int):
def max(other: Hand) =
Hand(red max other.red, green max other.green, blue max other.blue)
def power = red * green * blue
case class Game(id: Int, hands: List[Hand]):
def power =
hands.foldLeft(Hand(0, 0, 0))(_ max _).power
object Parser extends RegexParsers:
val num = """(0|[1-9]\d*)""".r ^^ { _.toInt }
val update =
num ~ """(red|green|blue)""".r ^^ { case (num ~ color) =>
color match
case "red" => (h: Hand) => h.copy(red = num)
case "green" => (h: Hand) => h.copy(green = num)
case "blue" => (h: Hand) => h.copy(blue = num)
}
val hand = rep1sep(update, ",").map(_.foldRight(Hand(0, 0, 0))(_(_)))
val game = "Game" ~ num ~ ":" ~ repsep(hand, ";") ^^ {
case (_ ~ num ~ _ ~ hands) => Game(num, hands)
}
end Parser
// Part 1
def getGames = lines.map(Parser.parse(Parser.game, _).get)
def part1 =
val games = getGames.toList
val res =
games
.filter(g =>
g.hands.forall(h => h.red <= 12 && h.green <= 13 && h.blue <= 14)
)
.map(_.id)
.sum
println(res)
def part2 =
val res = getGames.map(_.power).sum
println(res)
@main def Day2(part: Int) = part match
case 1 => part1
case 2 => part2