Day 6 solution

src/Day06.kt

@@ -0,0 +1,55 @@
+fun main() {
+
+    data class Race(val time: Long, val distance: Long)
+
+    fun part1(input: List<String>) : Int {
+        val times = input[0].split(":")[1].split(" ").filter{ it.isNotEmpty() }.map { it.toLong() }
+        val distances = input[1].split(":")[1].split(" ").filter{ it.isNotEmpty() }.map { it.toLong() }
+
+        val races = times.zip(distances).map { Race(it.first, it.second) }
+
+        val results = mutableListOf<Int>()
+        for (race in races){
+            val possibleTimes = 0..race.time
+            val possibleDistances = possibleTimes.map {
+                it * (possibleTimes.last - it)
+            }.toList()
+
+            val possibleRaces = possibleTimes.zip(possibleDistances).map { Race(it.first, it.second) }
+            val winningRaces = possibleRaces.filter{ zeRace -> zeRace.distance > race.distance }
+
+            results += winningRaces.size
+        }
+
+        return results.reduce { acc, i ->  acc * i }
+
+    }
+
+    fun part2(input: List<String>) : Int {
+
+        val times = input[0].split(":")[1].filter { !it.isWhitespace() }.toLong()
+        val distances = input[1].split(":")[1].filter { !it.isWhitespace() }.toLong()
+
+        val race = Race(times, distances)
+
+        val possibleTimes = 0..race.time
+        val possibleDistances = possibleTimes.map {
+            it * (possibleTimes.last - it)
+        }.toList()
+
+        val possibleRaces = possibleTimes.zip(possibleDistances).map { Race(it.first, it.second) }
+        val winningRaces = possibleRaces.filter{ zeRace -> zeRace.distance > race.distance }
+
+        return winningRaces.size
+    }
+
+    val testInput = readInput("Day06_test")
+    check(part1(testInput) == 288)
+
+    val input = readInput("Day06")
+    part1(input).println()
+
+    check(part2(testInput) == 71503)
+
+    part2(input).println()
+}