Clean-up day 5

PaulWoitaschek · Dec 5, 2024 · 40c2c3d · 40c2c3d
1 parent 3a45177
commit 40c2c3d
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Showing 2 changed files with 29 additions and 46 deletions.
diff --git a/2024/src/main/kotlin/aoc/year2024/Day5.kt b/2024/src/main/kotlin/aoc/year2024/Day5.kt
@@ -2,58 +2,41 @@ package aoc.year2024
 
 import aoc.library.Puzzle
 
-object Day5 : Puzzle<Long, Long>(day = 5) {
+object Day5 : Puzzle<Int, Int>(day = 5) {
 
-  override fun solvePart1(input: String): Long {
-    //  println(input)
-
-    val (orderingRulesValue, pagesValue) = input.split("\n\n")
-
-    val orderingRules = orderingRulesValue.lines().map {
-      val (l, r) = it.split("|")
-      l.toLong() to r.toLong()
-    }
-
-    val pages = pagesValue.lines()
-      .map {
-        it.split(",").map { it.toLong() }
-      }
-
-    val comparator = Comparator<Long> { o1, o2 ->
-      val rule = orderingRules.first { (it.first == o1 && it.second == o2) || (it.first == o2 && it.second == o1) }
-      if (o1 == rule.first) -1 else 1
-    }
+  override fun solvePart1(input: String): Int {
+    val (pages, comparator) = parse(input)
+    return pages
+      .filter { it.sortedWith(comparator) == it }
+      .sumOf { it[it.count() / 2] }
+  }
 
+  override fun solvePart2(input: String): Int {
+    val (pages, comparator) = parse(input)
     return pages
-      .filter {
-        it.sortedWith(comparator) == it
-      }
+      .filter { it.sortedWith(comparator) != it }
+      .map { it.sortedWith(comparator) }
       .sumOf { it[it.count() / 2] }
   }
 
-  override fun solvePart2(input: String): Long {
+  private fun parse(input: String): Pair<List<List<Int>>, Comparator<Int>> {
     val (orderingRulesValue, pagesValue) = input.split("\n\n")
+    return getPages(pagesValue) to comparator(orderingRulesValue)
+  }
 
-    val orderingRules = orderingRulesValue.lines().map {
-      val (l, r) = it.split("|")
-      l.toLong() to r.toLong()
-    }
-
-    val pages = pagesValue.lines()
-      .map {
-        it.split(",").map { it.toLong() }
-      }
+  private fun getPages(pagesValue: String) = pagesValue.lines().map { page ->
+    page.split(",").map(String::toInt)
+  }
 
-    val comparator = Comparator<Long> { o1, o2 ->
-      val rule = orderingRules.first { (it.first == o1 && it.second == o2) || (it.first == o2 && it.second == o1) }
-      if (o1 == rule.first) -1 else 1
+  private fun comparator(orderingRulesValue: String): Comparator<Int> {
+    val orderingRules = mutableMapOf<Pair<Int, Int>, Int>()
+    orderingRulesValue.lines().forEach {
+      val (l, r) = it.split("|").map(String::toInt)
+      orderingRules[l to r] = -1
+      orderingRules[r to l] = 1
+    }
+    return Comparator { o1, o2 ->
+      orderingRules.getValue(o1 to o2)
     }
-
-    return pages
-      .filter {
-        it.sortedWith(comparator) != it
-      }
-      .map { it.sortedWith(comparator) }
-      .sumOf { it[it.count() / 2] }
   }
 }
diff --git a/2024/src/test/kotlin/aoc/year2024/Day5Test.kt b/2024/src/test/kotlin/aoc/year2024/Day5Test.kt
@@ -2,7 +2,7 @@ package aoc.year2024
 
 import aoc.library.solvePart1
 import aoc.library.solvePart2
-import io.kotest.matchers.longs.shouldBeExactly
+import io.kotest.matchers.ints.shouldBeExactly
 import org.junit.jupiter.api.Test
 
 class Day5Test {
@@ -44,7 +44,7 @@ class Day5Test {
 
   @Test
   fun part1() {
-    Day5.solvePart1() shouldBeExactly 42
+    Day5.solvePart1() shouldBeExactly 5747
   }
 
   @Test
@@ -84,6 +84,6 @@ class Day5Test {
 
   @Test
   fun part2() {
-    Day5.solvePart2() shouldBeExactly 42
+    Day5.solvePart2() shouldBeExactly 5502
   }
 }