2022 Day 5 Scala

2022/day5.scala

@@ -0,0 +1,59 @@
+import java.nio.file.Files
+import java.nio.file.Paths
+import scala.collection.mutable.ArrayDeque
+
+type Stack[A] = ArrayDeque[A]
+val Stack = ArrayDeque
+
+val numberPattern = raw"((?:(?<!\d)-)?\d+)".r
+
+extension (s: String) def partition(sep: String = "\n\n"): (String, String) =
+	val ss = s.split(sep, 2)
+	(ss(0), ss(1))
+
+extension (s: String) def partition2(sep: String = "\n\n", sep2 : String = "\n"): (Array[String], Array[String]) =
+	val ss = s.split(sep, 2)
+	(ss(0).split(sep2), ss(1).split(sep2))
+
+extension (aos: Seq[String]) def transpose(reverseX: Boolean = false, reverseY: Boolean = false): Seq[String] =
+	val mapping: Function[Int, String] =
+		if reverseY then (i => aos.reverse.map(_.substring(i,i+1)).reduceLeft(_+_))
+		else (i => aos.map(_.substring(i,i+1)).reduceLeft(_+_))
+	if reverseX then
+		(0 until aos(0).length).reverse.map(mapping)
+	else
+		(0 until aos(0).length).map(mapping)
+
+def getStacksString(stacks: Map[Int, Stack[Char]]): String = stacks.keys.toBuffer.sorted.map(stacks(_).last.toString).reduceLeft(_+_)
+
+@main def main() =
+	val (input_stacks, input_orders) = Files.readString(Paths.get("input/5")).partition2()
+	val stacks_s = input_stacks
+		.transpose(reverseY = true)
+		.map(_.replaceAll(raw"[\[\]]", " ").strip)
+		.filter(_.length > 0)
+		.map(s => (s.substring(0,1).toInt, s.substring(1))).toMap
+	val orders = input_orders.map(numberPattern.findAllIn(_).map(_.toInt).toArray).toArray  // Can't leave lazy or Part 1 will consume it all
+
+	var stacks: Map[Int, Stack[Char]] = stacks_s.map((k,v) => (k, v.toCharArray.to(Stack))).toMap
+	for order <- orders do
+		val (amount, i_source, i_dest) = (order(0), order(1), order(2))
+		val source = stacks(i_source)
+		val dest = stacks(i_dest)
+		// println(s"Moving $amount from ${source.mkString} to ${dest.mkString}")
+		// print(s"Doing amount $amount : ")
+		for _ <- 1 to amount do
+			dest.append(source.removeLast())
+			// print(". ")
+		// print("\n")
+		// println(s"Moved $amount from ${source.mkString} to ${dest.mkString}")
+	println(s"Part 1: ${getStacksString(stacks)}")
+
+	stacks = stacks_s.map((k,v) => (k, v.toCharArray.to(Stack))).toMap
+	for order <- orders do
+		val (amount, i_source, i_dest) = (order(0), order(1), order(2))
+		val source = stacks(i_source)
+		val dest = stacks(i_dest)
+		dest.appendAll(source.takeRight(amount))
+		source.dropRightInPlace(amount)
+	println(s"Part 2: ${getStacksString(stacks)}")