🎄Advent of Code - Day 6 ✨part 2

src/main/kotlin/AdventOfCode2023/day6/WaitForIt.kt

@@ -0,0 +1,41 @@
+package AdventOfCode2023.day6
+
+import AdventOfCode.Puzzle
+import java.util.stream.Collectors
+
+data class Race(val raceTime: Long, val distance: Long)
+class WaitForIt : Puzzle("2023", "6") {
+
+    fun getRaceTimesPart1(): List<Race> {
+        return inputData.map {
+            // Split on spaces, ignore first item, transform tokens to integers
+            it.split(Regex("\\s")).drop(1).map { it.trim().toLongOrNull() }.filterNotNull()
+        }.zipWithNext().map {
+            // Take the zipped lines (since we only have 2) and transform them into races.
+            it.first.mapIndexed { index, i ->  Race(i, it.second[index])}
+        }.flatten().also { println("The input is $it") }
+    }
+
+    override fun partOne() {
+        val raceTimes = getRaceTimesPart1().map {
+            // here we transform a race into a list of all the possible combinations that we can have
+            (1..<it.raceTime).map { time -> Race((it.raceTime - time)* time, it.distance) }
+        }.parallelStream().map {
+            // Here we filter out the losing races
+            it.filter { it.raceTime > it.distance }.count()
+        }.reduce { acc, i -> acc * i }.get()
+
+        println("The number of ways the record was beaten $raceTimes.")
+    }
+
+    override fun partTwo() {
+        listOf(Race(49787980, 298118510661181)).map {
+            // here we transform a race into a list of all the possible combinations that we can have
+            (1..<it.raceTime).toList().parallelStream().map { time -> Race((it.raceTime - time)* time, it.distance) }.collect(
+                Collectors.toList())
+        }.map {
+            // Here we filter out the losing races
+            it.parallelStream().filter { it.raceTime > it.distance }.count()
+        }.reduce { acc, i -> acc * i }.also { println("The number of ways the record was beaten $it.") }
+    }
+}

src/main/kotlin/Main.kt

@@ -1,10 +1,10 @@
-import AdventOfCode2023.day4.Scratchcards
+import AdventOfCode2023.day6.WaitForIt
 import kotlin.system.measureTimeMillis
 
 fun main(args: Array<String>) {
-    val t = Scratchcards()
-    // t.partOne()
+    val t = WaitForIt()
     val time = measureTimeMillis {
+//        t.partOne()
          t.partTwo()
     }
     println("Took $time ms.")

src/main/resources/aoc2023/input_day6.txt

@@ -0,0 +1,2 @@
+Time:  49787980
+Distance:  298118510661181