Adding day 18 p1 and 19 p1 + creating folder 2018

2018/day14/part1.scala

@@ -0,0 +1,42 @@
+import scala.io.StdIn.readInt
+
+case class Turn(recipes: Vector[Int], idx1: Int, idx2: Int, turnNb: Int) {
+  def newScores(a: Int, b: Int): Vector[Int] =
+    (a + b).toString.map(_.toInt - '0').toVector
+
+  def next: Turn = {
+    val newRecipes = recipes ++ newScores(recipes(idx1), recipes(idx2))
+    val newIdx1 = (idx1 + (newRecipes(idx1) + 1)) % newRecipes.size
+    val newIdx2 = (idx2 + (newRecipes(idx2) + 1)) % newRecipes.size
+    Turn(newRecipes, newIdx1, newIdx2, turnNb + 1)
+  }
+
+  override def toString: String =
+    recipes.zipWithIndex.map {
+      case (v, k) => k match {
+        case _ if k == idx1 => s"($v)"
+        case _ if k == idx2 => s"[$v]"
+        case _ => s" $v "
+      }
+    }.mkString(" ")
+
+  def computeScoreAt(n: Int): Option[String] =
+    recipes match {
+      case _ if recipes.size < n + 10 => None
+      case _ => Some(recipes.slice(n, n + 10).mkString(""))
+    }
+}
+
+val input = readInt
+
+val turn0 = Turn(Vector(3, 7), 0, 1, 0)
+
+val endTurn = Iterator.iterate(turn0)(_.next)
+  .filter(_.recipes.length >= input + 11)
+  .next
+
+// println(s"Score: ${endTurn.computeScoreAt(5)} - Expected: 0124515891")
+// println(s"Score: ${endTurn.computeScoreAt(18)} - Expected: 9251071085")
+// println(s"Score: ${endTurn.computeScoreAt(2018)} - Expected: 5941429882")
+
+println(s"Score: ${endTurn.computeScoreAt(input).get}")