Solve 2023 day 23 part 2 naively

sim642 · Dec 23, 2023 · 4946473 · 4946473
1 parent c714473
commit 4946473
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Showing 2 changed files with 12 additions and 3 deletions.
diff --git a/src/main/scala/eu/sim642/adventofcode2023/Day23.scala b/src/main/scala/eu/sim642/adventofcode2023/Day23.scala
@@ -16,15 +16,15 @@ object Day23 {
     '<' -> Pos(-1, 0),
   )
 
-  def longestHike(grid: Grid[Char]): Int = {
+  def longestHike(grid: Grid[Char], slopes: Boolean = true): Int = {
 
     val graphTraversal = new GraphTraversal[HikePos] with UnitNeighbors[HikePos] {
       override val startNode: HikePos = HikePos(Pos(1, 0), Set(Pos(1, 0))) // TODO: don't hardcode
 
       override def unitNeighbors(hikePos: HikePos): IterableOnce[HikePos] = {
         val HikePos(pos, path) = hikePos
         for {
-          offset <- if (grid(pos) == '.') Pos.axisOffsets else Seq(slopeOffsets(grid(pos)))
+          offset <- if (!slopes || grid(pos) == '.') Pos.axisOffsets else Seq(slopeOffsets(grid(pos)))
           newPos = pos + offset
           if grid.containsPos(newPos)
           if grid(newPos) != '#'
@@ -49,6 +49,7 @@ object Day23 {
   lazy val input: String = scala.io.Source.fromInputStream(getClass.getResourceAsStream("day23.txt")).mkString.trim
 
   def main(args: Array[String]): Unit = {
-    println(longestHike(parseGrid(input)))
+    //println(longestHike(parseGrid(input)))
+    println(longestHike(parseGrid(input), slopes = false))
   }
 }
diff --git a/src/test/scala/eu/sim642/adventofcode2023/Day23Test.scala b/src/test/scala/eu/sim642/adventofcode2023/Day23Test.scala
@@ -37,4 +37,12 @@ class Day23Test extends AnyFunSuite {
   ignore("Part 1 input answer") { // TODO: optimize
     assert(longestHike(parseGrid(input)) == 2414)
   }
+
+  test("Part 2 examples") {
+    assert(longestHike(parseGrid(exampleInput), slopes = false) == 154)
+  }
+
+  ignore("Part 2 input answer") { // TODO: optimize
+    assert(longestHike(parseGrid(input), slopes = false) == 2414)
+  }
 }