Merge pull request #36 from ephemient/kt/day4

ephemient · Dec 4, 2024 · a6ef04b · a6ef04b
2 parents 77e7fb8 + 8ea9827
commit a6ef04b
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Showing 2 changed files with 10 additions and 11 deletions.
diff --git a/kt/aoc2024-lib/src/commonMain/kotlin/com/github/ephemient/aoc2024/Day4.kt b/kt/aoc2024-lib/src/commonMain/kotlin/com/github/ephemient/aoc2024/Day4.kt
@@ -1,14 +1,12 @@
 package com.github.ephemient.aoc2024
 
-class Day4(
-    input: String,
-) {
+class Day4(input: String) {
     private val lines = input.lines()
 
     fun part1() = lines.indices.sumOf { y ->
         lines[y].indices.sumOf { x ->
             Direction.entries.count { (dx, dy) ->
-                "XMAS".withIndex().all { (i, c) ->
+                XMAS.withIndex().all { (i, c) ->
                     lines.getOrNull(y + i * dy)?.getOrNull(x + i * dx) == c
                 }
             }
@@ -20,12 +18,8 @@ class Day4(
             if (lines[y][x] != 'A') return@count false
             val n = lines.getOrNull(y - 1) ?: return@count false
             val s = lines.getOrNull(y + 1) ?: return@count false
-            val nw = n.getOrNull(x - 1) ?: return@count false
-            val ne = n.getOrNull(x + 1) ?: return@count false
-            val sw = s.getOrNull(x - 1) ?: return@count false
-            val se = s.getOrNull(x + 1) ?: return@count false
-            (nw == 'M' && se == 'S' || se == 'M' && nw == 'S') &&
-                (sw == 'M' && ne == 'S' || ne == 'M' && sw == 'S')
+            setOf(n.getOrNull(x - 1), s.getOrNull(x + 1)) == MS &&
+                setOf(n.getOrNull(x + 1), s.getOrNull(x - 1)) == MS
         }
     }
 
@@ -43,4 +37,9 @@ class Day4(
         operator fun component1() = dx
         operator fun component2() = dy
     }
+
+    companion object {
+        private const val XMAS = "XMAS"
+        private val MS = "MS".toSet()
+    }
 }
diff --git a/kt/graalvm/build.gradle.kts b/kt/graalvm/build.gradle.kts
@@ -72,7 +72,7 @@ val externalTestClasspath = configurations.resolvable("externalTestClasspath") {
 configurations.testImplementation {
     extendsFrom(externalTestClasses.get())
 }
-tasks.named<Test>("test") {
+tasks.test {
     testClassesDirs = files(testClassesDirs, externalTestClasspath.get())
     useJUnitPlatform()
 }