50 lines
1.6 KiB
Scala
50 lines
1.6 KiB
Scala
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import scala.io.Source
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import scala.math.floorMod
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enum RPS(val score: Int):
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case Rock extends RPS(1)
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case Paper extends RPS(2)
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case Scissors extends RPS(3)
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def <=>(other: RPS) =
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(other.score - score) match
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case -2 | 1 => -1
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case -1 | 2 => 1
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case _ => 0
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def >(other: RPS) = <=>(other) > 0
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def <(other: RPS) = <=>(other) < 0
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def ==(other: RPS) = <=>(other) == 0
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def +(amount: Int) = RPS.fromOrdinal(floorMod(this.ordinal + amount, 3))
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def -(amount: Int) = RPS.fromOrdinal(floorMod(this.ordinal - amount, 3))
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def resultScore(a: RPS, b: RPS) = a <=> b match
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case -1 => 0
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case 1 => 6
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case _ => 3
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val moveMap = Map("A"->RPS.Rock, "B"->RPS.Paper, "C"->RPS.Scissors, "X"->RPS.Rock, "Y"->RPS.Paper, "Z"->RPS.Scissors)
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@main def main() =
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val strategyGuide = Source.fromFile("day2-input").getLines.map(_.split(" ")).toArray // Can't leave it lazy as Part 1 will consume it
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// val strategyGuide = Source.fromString("A Y\nB X\nC Z\n").getLines.map(_.split(" ")).toArray
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// Part 1 - evaluate all moves in the guide using moveMap and tally score
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var score = 0
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for movePair <- strategyGuide do
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val opponentMove = moveMap(movePair(0))
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val ourMove = moveMap(movePair(1))
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score += resultScore(ourMove, opponentMove) + ourMove.score
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println(score)
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// Part 2 - X->lose, Y->draw, Z->win
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score = 0
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for movePair <- strategyGuide do
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val opponentMove = moveMap(movePair(0))
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val ourMove = movePair(1) match
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case "X" => opponentMove - 1
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case "Y" => opponentMove
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case "Z" => opponentMove + 1
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score += resultScore(ourMove, opponentMove) + ourMove.score
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println(score)
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