Day 20 shave off some cycles

2024-12-20 19:17:00 +01:00
parent cdf14fdada
commit 58710aca7a
1 changed files with 6 additions and 6 deletions
--- a/aoc/src/dev/ctsk/aoc/days/Day20.scala
+++ b/aoc/src/dev/ctsk/aoc/days/Day20.scala
@@ -20,11 +20,11 @@ object Day20 extends Solver(20):

    def cheats(radius: Int): Int =
      trace.indices.par
-        .map(a =>
-          (a + 1 until trace.length)
-            .count(b =>
-              val (from, fromDist) = (trace(a), trace.length - a)
-              val (to, toDist) = (trace(b), trace.length - b)
+        .map(toDist =>
+          (toDist + 100 until trace.length)
+            .count(fromDist =>
+              val from = trace(toDist)
+              val to = trace(fromDist)
              val dist = (from - to).manhattan

              dist <= radius && (fromDist - toDist >= 100 + dist)