added fast compiling day 17 part 2 in Scala

README.md

@@ -38,7 +38,7 @@ To run all solutions, simply run `./gradlew run`. If you want to run the solutio
 | 14  | ⭐        | ⭐                                                                                                                         |
 | 15  | ⭐        | ⭐                                                                                                                         |
 | 16  | ⭐        | ⭐ <img src="https://scalacenter.github.io/scala-advent-of-code/img/scala-icon.png" width="15" height="15" alt="Scala" />  |
-| 17  | ⭐        | ⭐                                                                                                                         |
+| 17  | ⭐        | ⭐ <img src="https://scalacenter.github.io/scala-advent-of-code/img/scala-icon.png" width="15" height="15" alt="Scala" />  |
 | 18  | ⭐        | ⭐                                                                                                                         |
 | 19  | ⭐        | ⭐                                                                                                                         |
 | 20  | ⭐        | ⭐                                                                                                                         |

aoc16/build.gradle

@@ -12,7 +12,7 @@ dependencies {
     implementation 'org.jetbrains.kotlin:kotlin-stdlib-jdk8'
     implementation 'org.scala-lang:scala3-library_3:3.3.1'
 
-    testImplementation 'org.junit.jupiter:junit-jupiter:5.9.1'
+    testImplementation 'org.junit.jupiter:junit-jupiter:5.10.1'
     testImplementation 'org.jetbrains.kotlin:kotlin-test-junit'
     testImplementation 'org.scalatest:scalatest_3:3.2.17'
     testImplementation 'org.scalatestplus:junit-5-10_3:3.2.17.0'

aoc17/build.gradle

@@ -4,14 +4,18 @@ import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
 plugins {
     id 'application'
     id 'org.jetbrains.kotlin.jvm' version '1.7.22'
+    id 'scala'
 }
 
 dependencies {
     implementation 'org.jetbrains.kotlin:kotlin-reflect'
     implementation 'org.jetbrains.kotlin:kotlin-stdlib-jdk8'
+    implementation 'org.scala-lang:scala3-library_3:3.3.1'
 
-    testImplementation 'org.junit.jupiter:junit-jupiter:5.9.1'
+    testImplementation 'org.junit.jupiter:junit-jupiter:5.10.1'
     testImplementation 'org.jetbrains.kotlin:kotlin-test-junit'
+    testImplementation 'org.scalatest:scalatest_3:3.2.17'
+    testImplementation 'org.scalatestplus:junit-5-10_3:3.2.17.0'
 }
 
 tasks.withType(KotlinCompile).configureEach {
@@ -22,7 +26,9 @@ tasks.withType(KotlinCompile).configureEach {
 }
 
 tasks.withType(Test).configureEach {
-    useJUnitPlatform()
+    useJUnitPlatform {
+        includeEngines("junit-jupiter", "scalatest")
+    }
 
     testLogging {
         exceptionFormat = TestExceptionFormat.FULL

aoc17/src/main/scala/de/havox_design/aoc2022/day17/Day17.scala

@@ -0,0 +1,38 @@
+package de.havox_design.aoc2022.day17
+
+object Day17 {
+  def solvePart2(filename: String, runs: Int = 10000): Long = {
+    val guess = 1000
+    val height = simulate(readData(filename).next())
+      .slice(1, 5 * guess)
+      .toSeq
+    val delta = height.sliding(2).map(s => s.last - s.head).toSeq
+    val end = delta.size - guess
+    val start = delta.lastIndexOfSlice(delta.takeRight(guess), end - 1)
+    val cycleHeight = height(end) - height(start)
+    val cycleWidth = end - start
+    val offset = 1000000000000L - 1 - start
+    val quotient = offset / cycleWidth
+    val remainder = offset % cycleWidth
+
+    (quotient * cycleHeight) + height(start + remainder.toInt)
+  }
+
+  def main(args: Array[String]): Unit = {
+    println("Solution for part2: " + solvePart2("input.txt"))
+  }
+
+  private def simulate(jets: String): Iterator[Int] =
+    val initial = State(jets, Set.tabulate(8)(Point(_, 0)), 0, 0, 0)
+
+    Iterator
+      .iterate(initial)(_.step)
+      .map(_.height)
+
+  private def readData(filename: String): Iterator[String] =
+    scala
+      .io
+      .Source
+      .fromResource(filename)
+      .getLines()
+}

aoc17/src/main/scala/de/havox_design/aoc2022/day17/Point.scala

@@ -0,0 +1,7 @@
+package de.havox_design.aoc2022.day17
+
+case class Point(x: Int, y: Int)
+
+extension (shape: Set[Point])
+  def move(dx: Int, dy: Int): Set[Point] = shape.map(p => Point(p.x + dx, p.y + dy))
+  def canMove(grid: Set[Point]): Boolean = shape.forall(p => p.x > 0 && p.x < 8 && !grid.contains(p))

aoc17/src/main/scala/de/havox_design/aoc2022/day17/State.scala

@@ -0,0 +1,37 @@
+package de.havox_design.aoc2022.day17
+
+val shapes = Seq(
+  Set(Point(0, 0), Point(1, 0), Point(2, 0), Point(3, 0)),
+  Set(Point(1, 0), Point(0, 1), Point(1, 1), Point(2, 1), Point(1, 2)),
+  Set(Point(0, 0), Point(1, 0), Point(2, 0), Point(2, 1), Point(2, 2)),
+  Set(Point(0, 0), Point(0, 1), Point(0, 2), Point(0, 3)),
+  Set(Point(0, 0), Point(1, 0), Point(0, 1), Point(1, 1)))
+
+case class State(jets: String, grid: Set[Point], shapeIndex: Int, jetIndex: Int, height: Int):
+  def step: State =
+    val initialShape = shapes(shapeIndex % shapes.size)
+      .move(3, height + 4)
+    val (nextShape, nextJetIndex) = fall(initialShape, jetIndex)
+    val nextHeight = height
+      .max(nextShape.map(_.y).max)
+
+    State(jets, grid ++ nextShape, shapeIndex + 1, nextJetIndex, nextHeight)
+
+  private def fall(shape: Set[Point], jetIndex: Int): (Set[Point], Int) =
+    val jet = jets(jetIndex % jets.length)
+    val first = if jet != '>' then
+      shape.move(-1, 0)
+    else
+      shape.move(1, 0)
+    val second = if !first.canMove(grid) then
+      shape
+    else
+      first
+    val third = second
+      .move(0, -1)
+
+    if !third.canMove(grid) then
+      (second, jetIndex + 1)
+    else
+      fall(third, jetIndex + 1)
+end State

aoc17/src/test/scala/de/havox_design/aoc2022/day17/Day17ScalaTest.scala

@@ -0,0 +1,14 @@
+package de.havox_design.aoc2022.day17
+
+import Day17._
+import org.scalatest.funsuite.AnyFunSuite
+
+class Day17ScalaTest extends AnyFunSuite {
+  test("Day 17 - Part 2") {
+    println("Solution for part2: " + solvePart2("input.txt"))
+  }
+
+  test("Day 17 - Part 2 - Sample") {
+    assert(solvePart2("sample.txt") == 1514285714288L)
+  }
+}

build.gradle

@@ -4,7 +4,7 @@ plugins {
 
 // project meta data
 group 'de.havox_design.aoc2022'
-version '1.0.4'
+version '1.0.5'
 
 // Switch to gradle "all" distribution.
 wrapper {