No need to keep the whole Set

ephemient · Dec 4, 2023 · b4a1ef9 · b4a1ef9
1 parent fbf4c3d
commit b4a1ef9
Showing 1 changed file with 3 additions and 3 deletions.
diff --git a/kt/aoc2023-lib/src/commonMain/kotlin/com/github/ephemient/aoc2023/Day4.kt b/kt/aoc2023-lib/src/commonMain/kotlin/com/github/ephemient/aoc2023/Day4.kt
@@ -4,14 +4,14 @@ class Day4(input: String) {
     private val cards = input.lines().mapNotNull { line ->
         val (left, right) = line.substringAfter(':').split('|', limit = 2).takeIf { it.size == 2 }
             ?: return@mapNotNull null
-        left.trim().split(WHITESPACE).toSet() intersect right.trim().split(WHITESPACE).toSet()
+        (left.trim().split(WHITESPACE).toSet() intersect right.trim().split(WHITESPACE).toSet()).size
     }
 
-    fun part1(): Int = cards.sumOf { 1 shl it.size shr 1 }
+    fun part1(): Int = cards.sumOf { 1 shl it shr 1 }
 
     fun part2(): Int = IntArray(cards.size) { 1 }.also { counts ->
         for ((i, card) in cards.withIndex()) {
-            for (j in i + 1..(i + card.size).coerceAtMost(counts.lastIndex)) {
+            for (j in i + 1..(i + card).coerceAtMost(counts.lastIndex)) {
                 counts[j] += counts[i]
             }
         }