AdventOfCode/2022/day2.scala

50 lines
1.6 KiB
Scala

import scala.io.Source
import scala.math.floorMod
enum RPS(val score: Int):
case Rock extends RPS(1)
case Paper extends RPS(2)
case Scissors extends RPS(3)
def <=>(other: RPS) =
(other.score - score) match
case -2 | 1 => -1
case -1 | 2 => 1
case _ => 0
def >(other: RPS) = <=>(other) > 0
def <(other: RPS) = <=>(other) < 0
def ==(other: RPS) = <=>(other) == 0
def +(amount: Int) = RPS.fromOrdinal(floorMod(this.ordinal + amount, 3))
def -(amount: Int) = RPS.fromOrdinal(floorMod(this.ordinal - amount, 3))
def resultScore(a: RPS, b: RPS) = a <=> b match
case -1 => 0
case 1 => 6
case _ => 3
val moveMap = Map("A"->RPS.Rock, "B"->RPS.Paper, "C"->RPS.Scissors, "X"->RPS.Rock, "Y"->RPS.Paper, "Z"->RPS.Scissors)
@main def main() =
val strategyGuide = Source.fromFile("input/2").getLines.map(_.split(" ")).toArray // Can't leave it lazy as Part 1 will consume it
// val strategyGuide = Source.fromString("A Y\nB X\nC Z\n").getLines.map(_.split(" ")).toArray
// Part 1 - evaluate all moves in the guide using moveMap and tally score
var score = 0
for movePair <- strategyGuide do
val opponentMove = moveMap(movePair(0))
val ourMove = moveMap(movePair(1))
score += resultScore(ourMove, opponentMove) + ourMove.score
println(score)
// Part 2 - X->lose, Y->draw, Z->win
score = 0
for movePair <- strategyGuide do
val opponentMove = moveMap(movePair(0))
val ourMove = movePair(1) match
case "X" => opponentMove - 1
case "Y" => opponentMove
case "Z" => opponentMove + 1
score += resultScore(ourMove, opponentMove) + ourMove.score
println(score)