From 746abfc9e58d0be0bc0b1d9e8bfa2f7f87e18a77 Mon Sep 17 00:00:00 2001
From: Simmo Saan <simmo.saan@gmail.com>
Date: Mon, 11 Dec 2023 08:37:57 +0200
Subject: [PATCH] Deduplicate 2023 day 11

---
 .../eu/sim642/adventofcode2023/Day11.scala    | 50 +++++++++----------
 .../sim642/adventofcode2023/Day11Test.scala   | 10 ++--
 2 files changed, 29 insertions(+), 31 deletions(-)

diff --git a/src/main/scala/eu/sim642/adventofcode2023/Day11.scala b/src/main/scala/eu/sim642/adventofcode2023/Day11.scala
index 697dadbb..1e937058 100644
--- a/src/main/scala/eu/sim642/adventofcode2023/Day11.scala
+++ b/src/main/scala/eu/sim642/adventofcode2023/Day11.scala
@@ -5,35 +5,33 @@ import eu.sim642.adventofcodelib.pos.Pos
 
 object Day11 {
 
-  def sumDistances(galaxies: Seq[Pos]): Int = {
-    val xs = galaxies.map(_.x).toSet
-    val freeXs = (0 to xs.max).toSet -- xs
-    val ys = galaxies.map(_.y).toSet
-    val freeYs = (0 to ys.max).toSet -- ys
-
-    (for {
-      (galaxy1, i) <- galaxies.view.zipWithIndex
-      galaxy2 <- galaxies.view.drop(i + 1)
-      galaxyMin = galaxy1 min galaxy2
-      galaxyMax = galaxy1 max galaxy2
-    } yield (galaxy1 manhattanDistance galaxy2) + freeXs.count(x => galaxyMin.x < x && x < galaxyMax.x) + freeYs.count(y => galaxyMin.y < y && y < galaxyMax.y)).sum
+  trait Part {
+    val defaultExpansionFactor: Int
+
+    def sumDistances(galaxies: Seq[Pos], expansionFactor: Long = defaultExpansionFactor): Long = {
+      val xs = galaxies.map(_.x).toSet
+      val freeXs = (0 to xs.max).toSet -- xs
+      val ys = galaxies.map(_.y).toSet
+      val freeYs = (0 to ys.max).toSet -- ys
+
+      (for {
+        (galaxy1, i) <- galaxies.view.zipWithIndex
+        galaxy2 <- galaxies.view.drop(i + 1)
+        galaxyMin = galaxy1 min galaxy2
+        galaxyMax = galaxy1 max galaxy2
+      } yield (galaxy1 manhattanDistance galaxy2) + (expansionFactor - 1) * freeXs.count(x => galaxyMin.x < x && x < galaxyMax.x) + (expansionFactor - 1) * freeYs.count(y => galaxyMin.y < y && y < galaxyMax.y)).sum
+    }
   }
 
-  // TODO: deduplicate
-  def sumDistances2(galaxies: Seq[Pos], factor: Long = 1000000L): Long = {
-    val xs = galaxies.map(_.x).toSet
-    val freeXs = (0 to xs.max).toSet -- xs
-    val ys = galaxies.map(_.y).toSet
-    val freeYs = (0 to ys.max).toSet -- ys
+  object Part1 extends Part {
+    override val defaultExpansionFactor: Int = 2
+  }
 
-    (for {
-      (galaxy1, i) <- galaxies.view.zipWithIndex
-      galaxy2 <- galaxies.view.drop(i + 1)
-      galaxyMin = galaxy1 min galaxy2
-      galaxyMax = galaxy1 max galaxy2
-    } yield (galaxy1 manhattanDistance galaxy2) + (factor - 1) * freeXs.count(x => galaxyMin.x < x && x < galaxyMax.x) + (factor - 1) * freeYs.count(y => galaxyMin.y < y && y < galaxyMax.y)).sum
+  object Part2 extends Part {
+    override val defaultExpansionFactor: Int = 1000000
   }
 
+
   def parseGalaxies(input: String): Seq[Pos] = {
     val grid = input.linesIterator.map(_.toVector).toVector
     (for {
@@ -46,7 +44,7 @@ object Day11 {
   lazy val input: String = scala.io.Source.fromInputStream(getClass.getResourceAsStream("day11.txt")).mkString.trim
 
   def main(args: Array[String]): Unit = {
-    println(sumDistances(parseGalaxies(input)))
-    println(sumDistances2(parseGalaxies(input)))
+    println(Part1.sumDistances(parseGalaxies(input)))
+    println(Part2.sumDistances(parseGalaxies(input)))
   }
 }
diff --git a/src/test/scala/eu/sim642/adventofcode2023/Day11Test.scala b/src/test/scala/eu/sim642/adventofcode2023/Day11Test.scala
index 6bbb9b06..f333c91b 100644
--- a/src/test/scala/eu/sim642/adventofcode2023/Day11Test.scala
+++ b/src/test/scala/eu/sim642/adventofcode2023/Day11Test.scala
@@ -18,19 +18,19 @@ class Day11Test extends AnyFunSuite {
       |#...#.....""".stripMargin
 
   test("Part 1 examples") {
-    assert(sumDistances(parseGalaxies(exampleInput)) == 374)
+    assert(Part1.sumDistances(parseGalaxies(exampleInput)) == 374)
   }
 
   test("Part 1 input answer") {
-    assert(sumDistances(parseGalaxies(input)) == 9509330)
+    assert(Part1.sumDistances(parseGalaxies(input)) == 9509330)
   }
 
   test("Part 2 examples") {
-    assert(sumDistances2(parseGalaxies(exampleInput), 10) == 1030)
-    assert(sumDistances2(parseGalaxies(exampleInput), 100) == 8410)
+    assert(Part2.sumDistances(parseGalaxies(exampleInput), 10) == 1030)
+    assert(Part2.sumDistances(parseGalaxies(exampleInput), 100) == 8410)
   }
 
   test("Part 2 input answer") {
-    assert(sumDistances2(parseGalaxies(input)) == 635832237682L)
+    assert(Part2.sumDistances(parseGalaxies(input)) == 635832237682L)
   }
 }