feat(day15): part 2

Author: fdlk

day15.sc

@@ -9,21 +9,37 @@ case class Point(x: Int, y: Int) {
     copy(y = y - 1),
     copy(y = y + 1)
   )
+
   def manhattanDistance(to: Point): Int = (x - to.x).abs + (y - to.y).abs
 }
 
 val risk: Map[Point, Int] = input.zipWithIndex.flatMap { case (row, y) =>
   row.zipWithIndex.map { case (risk, x) => Point(x, y) -> risk.toString.toInt }
 }.toMap
 
-  val start = Point(0, 0)
-  val end = Point(input.head.length - 1, input.length - 1)
-
-class ChitonGrid() extends Grid[Point] {
+class ChitonGrid extends Grid[Point] {
   override def heuristicDistance(from: Point, to: Point) = from.manhattanDistance(to)
-  override def getNeighbours(state: Point) = state.neighbors.filter(risk.keySet.contains)
+
+  override def getNeighbours(state: Point) = state.neighbors.filter(risk.keySet)
+
   override def moveCost(from: Point, to: Point) = risk(to)
 }
 
-aStarSearch(start, end, new ChitonGrid())
+val part1 = aStarSearch(Point(0, 0), Point(input.head.length - 1, input.length - 1), new ChitonGrid)
+
+val width = input.head.length
+val height = input.length
+val riskPart2: Map[Point, Int] = (for (x <- input.head.indices;
+                                       y <- input.indices;
+                                       gridX <- 0 until 5;
+                                       gridY <- 0 until 5) yield
+  Point(x + gridX * width, y + gridY * width) -> ((risk(Point(x, y)) + gridX + gridY - 1) % 9 + 1)
+  ).toMap
+
+class ExtendedChitonGrid extends ChitonGrid {
+  override def getNeighbours(state: Point) = state.neighbors.filter(riskPart2.keySet)
+
+  override def moveCost(from: Point, to: Point) = riskPart2(to)
+}
 
+val part2 = aStarSearch(Point(0, 0), Point(width * 5 - 1, height * 5 - 1), new ExtendedChitonGrid)