feat(day06): both parts

Author: fdlk

day06.sc

@@ -0,0 +1,19 @@
+import common.loadPackets
+
+type Population = Map[Int, Long]
+val input = loadPackets(List("day06.txt")).head.split(",").map(_.toInt).toList
+
+val initialState: Population = input.groupBy(identity).view.mapValues(_.size.toLong).toMap
+
+def next(state: Population): Population = state.map {
+  case (timer, amount) if timer == 0 => List((6, amount), (8, amount))
+  case (timer, amount) => List((timer - 1, amount))
+}.toList.flatten
+  .foldLeft(Map[Int, Long]()) {
+    case (map, (timer, amount)) =>
+      map + (timer -> (map.getOrElse(timer, 0L) + amount))
+  }
+
+val part1 = Range(0, 80).foldLeft(initialState)((state, _) => next(state)).values.sum
+val part2 = Range(0, 256).foldLeft(initialState)((state, _) => next(state)).values.sum
+

src/main/resources/day06.txt

@@ -0,0 +1 @@
+5,3,2,2,1,1,4,1,5,5,1,3,1,5,1,2,1,4,1,2,1,2,1,4,2,4,1,5,1,3,5,4,3,3,1,4,1,3,4,4,1,5,4,3,3,2,5,1,1,3,1,4,3,2,2,3,1,3,1,3,1,5,3,5,1,3,1,4,2,1,4,1,5,5,5,2,4,2,1,4,1,3,5,5,1,4,1,1,4,2,2,1,3,1,1,1,1,3,4,1,4,1,1,1,4,4,4,1,3,1,3,4,1,4,1,2,2,2,5,4,1,3,1,2,1,4,1,4,5,2,4,5,4,1,2,1,4,2,2,2,1,3,5,2,5,1,1,4,5,4,3,2,4,1,5,2,2,5,1,4,1,5,1,3,5,1,2,1,1,1,5,4,4,5,1,1,1,4,1,3,3,5,5,1,5,2,1,1,3,1,1,3,2,3,4,4,1,5,5,3,2,1,1,1,4,3,1,3,3,1,1,2,2,1,2,2,2,1,1,5,1,2,2,5,2,4,1,1,2,4,1,2,3,4,1,2,1,2,4,2,1,1,5,3,1,4,4,4,1,5,2,3,4,4,1,5,1,2,2,4,1,1,2,1,1,1,1,5,1,3,3,1,1,1,1,4,1,2,2,5,1,2,1,3,4,1,3,4,3,3,1,1,5,5,5,2,4,3,1,4