Data update

Task/Padovan-sequence/Scala/padovan-sequence.scala

@@ -0,0 +1,54 @@
+object Padovan extends App {
+
+  val recurrences = new collection.mutable.ListBuffer[Int]()
+  val floors = new collection.mutable.ListBuffer[Int]()
+  val PP = 1.324717957244746025960908854
+  val SS = 1.0453567932525329623
+
+  for (i <- 0 until 64) {
+    recurrences += padovanRecurrence(i)
+    floors += padovanFloor(i)
+  }
+
+  println("The first 20 terms of the Padovan sequence:")
+  recurrences.slice(0, 20).foreach(term => print(s"${term} "))
+  println("\n")
+
+  println(s"Recurrence and floor functions agree for first 64 terms? ${recurrences == floors}")
+  println("")
+
+  val words = createLSystem()
+
+  println("The first 10 terms of the L-system:")
+  words.slice(0, 10).foreach(term => print(term + " "))
+  println("\n")
+
+  print("Length of first 32 terms produced from the L-system match Padovan sequence? ")
+  val wordLengths = words.map(_.length)
+  print(wordLengths.slice(0, 32) == recurrences.slice(0, 32))
+
+  def padovanRecurrence(n: Int): Int = {
+    if (n <= 2) 1 else recurrences(n - 2) + recurrences(n - 3)
+  }
+
+  def padovanFloor(aN: Int): Int = {
+    scala.math.floor(scala.math.pow(PP, aN - 1) / SS + 0.5).toInt
+  }
+
+  def createLSystem(): List[String] = {
+    var words = List("A")
+    var text = "A"
+
+    while (words.length < 32) {
+      text = text.flatMap {
+        case 'A' => "B"
+        case 'B' => "C"
+        case 'C' => "AB"
+      }
+      words = words :+ text
+    }
+
+    words
+  }
+
+}