From 0528d4b50ecb22920a56f05631d7c482e46e196d Mon Sep 17 00:00:00 2001
From: Luke Hubmayer-Werner <mongoose41@gmail.com>
Date: Fri, 2 Dec 2022 19:20:24 +1030
Subject: [PATCH] more scala

---
 2022/day2-v2.scala | 39 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)
 create mode 100644 2022/day2-v2.scala

diff --git a/2022/day2-v2.scala b/2022/day2-v2.scala
new file mode 100644
index 0000000..43a6f1d
--- /dev/null
+++ b/2022/day2-v2.scala
@@ -0,0 +1,39 @@
+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 +(amount: Int) = RPS.fromOrdinal(floorMod(ordinal + amount, 3))
+	def -(amount: Int) = RPS.fromOrdinal(floorMod(ordinal - amount, 3))
+	def -(other: RPS) = score - other.score
+
+	def vs(other: RPS) = floorMod(this - other, 3) match
+		case 1 => 6
+		case 2 => 0
+		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("day2-input").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
+	println(strategyGuide.map(movePair=>
+		val theirMove = moveMap(movePair(0))
+		val ourMove = moveMap(movePair(1))
+		ourMove.score + (ourMove vs theirMove)
+	).sum)
+
+	// Part 2 - X->lose, Y->draw, Z->win
+	println(strategyGuide.map(movePair=>
+		val theirMove = moveMap(movePair(0))
+		val ourMove = movePair(1) match
+			case "X" => theirMove - 1
+			case "Y" => theirMove
+			case "Z" => theirMove + 1
+		ourMove.score + (ourMove vs theirMove)
+	).sum)
\ No newline at end of file