cleanup

2024/src/main/scala/aoc2024/Day19.scala

@@ -5,8 +5,6 @@ import nmcb.predef.*
 
 object Day19 extends AoC:
 
-  case class Design(stripes: String)
-
   val (towels: Vector[String], designs: Vector[String]) =
     val Array(ts, ds) = input.split("\n\n").map(_.trim)
     (ts.split(',').map(_.trim).toVector, ds.linesIterator.toVector)

2024/src/main/scala/aoc2024/Day20.scala

@@ -10,11 +10,16 @@ object Day20 extends AoC:
 
   def cheats(path: Vector[Pos], timeframe: Long): Long =
     @tailrec
-    def trace(trail: Vector[(Pos,Int)], cheated: Long): Long =
+    def trace(trail: Vector[(Pos, Int)], cheated: Long): Long =
       if trail.nonEmpty then
-        val (from,time) = trail.head
-        val rest        = trail.tail
-        val saved = rest.flatMap((to,left) => when(from.manhattanDistance(to) <= timeframe)(left - time - from.manhattanDistance(to)))
+        val (from, time) = trail.head
+        val rest         = trail.tail
+
+        val saved =
+          rest.flatMap: (to,left) =>
+            val distance = from.manhattanDistance(to)
+            when(distance <= timeframe)(left - time - distance)
+
         trace(rest, cheated + saved.count(_ >= 100))
       else
         cheated

2024/src/main/scala/aoc2024/Day21.scala

@@ -29,7 +29,7 @@ object Day21 extends AoC:
         |<v>
         |""".stripMargin)
 
-  val directionButtonBy: Map[Dir,Button] =
+  val directionButtonBy: Map[Dir, Button] =
     Map(
       E -> '>',
       W -> '<',
@@ -56,16 +56,16 @@ object Day21 extends AoC:
             to -> (moves.count + shortestPathMoves(moves.pos, to, robot))
         .count
 
-    def shortestPathMoves(from: Pos, to: Pos, robot: Int): Long = cache.memoize(from,to,robot):
+    def shortestPathMoves(from: Pos, to: Pos, robot: Int): Long = cache.memoize(from, to, robot):
         Dijkstra
-          .breadthFirstSearch((from,Vector.empty[Button])):
-            case (p,pushes) if p == to => Right(
+          .breadthFirstSearch((from, Vector.empty[Button])):
+            case (p, pushes) if p == to => Right(
                 if robot < robots then
                   pointerMovesFor(pushes :+ Button.enter, robot + 1)
                 else
                   pushes.length + 1L
               )
-            case (p,code) => Left(
+            case (p, code) => Left(
                 p.directionTo(to)
                   .filterNot(d => keypadBy(robot).contains(p step d, Button.empty))
                   .map(d => (p step d, code :+ directionButtonBy(d)))

2024/src/main/scala/aoc2024/Day22.scala

@@ -35,10 +35,10 @@ object Day22 extends AoC:
     def sequence: Seq[Long] = p._1
     def price: Long         = p._2
 
-  def solve(secrets: Vector[Long]): Long =
+  def solve(secrets: Vector[Long], nth: Int): Long =
     secrets
       .flatMap: initial =>
-        Iterator.iterate(initial, 2001)(_.nextSecret)
+        Iterator.iterate(initial, nth + 1)(_.nextSecret)
           .map(_ % 10)
           .sliding(5)
           .map: prices =>
@@ -53,5 +53,5 @@ object Day22 extends AoC:
       .values
       .max
 
-  override lazy val answer1: Long = numbers.map(initial => Iterator.iterate(initial, 2001)(_.nextSecret).drain).sum
-  override lazy val answer2: Long = solve(numbers)
+  override lazy val answer1: Long = numbers.map(initial => Iterator.iterate(initial)(_.nextSecret).nth(2000)).sum
+  override lazy val answer2: Long = solve(numbers, 2000)