Data update

Task/Padovan-sequence/Kotlin/padovan-sequence.kotlin

@@ -0,0 +1,59 @@
+import kotlin.math.floor
+import kotlin.math.pow
+
+object CodeKt{
+
+    private val recurrences = mutableListOf<Int>()
+    private val floors = mutableListOf<Int>()
+    private const val PP = 1.324717957244746025960908854
+    private const val SS = 1.0453567932525329623
+
+    @JvmStatic
+    fun main(args: Array<String>) {
+        for (i in 0 until 64) {
+            recurrences.add(padovanRecurrence(i))
+            floors.add(padovanFloor(i))
+        }
+
+        println("The first 20 terms of the Padovan sequence:")
+        recurrences.subList(0, 20).forEach { term -> print("$term ") }
+        println("\n")
+
+        println("Recurrence and floor functions agree for first 64 terms? ${recurrences == floors}\n")
+
+        val words = createLSystem()
+
+        println("The first 10 terms of the L-system:")
+        words.subList(0, 10).forEach { term -> print("$term ") }
+        println("\n")
+
+        print("Length of first 32 terms produced from the L-system match Padovan sequence? ")
+        val wordLengths = words.map { it.length }
+        println(wordLengths == recurrences.subList(0, 32))
+    }
+
+    private fun padovanRecurrence(n: Int): Int =
+        if (n <= 2) 1 else recurrences[n - 2] + recurrences[n - 3]
+
+    private fun padovanFloor(n: Int): Int =
+        floor(PP.pow(n - 1) / SS + 0.5).toInt()
+
+    private fun createLSystem(): List<String> {
+        val words = mutableListOf<String>()
+        var text = "A"
+
+        while (words.size < 32) {
+            words.add(text)
+            text = text.map { ch ->
+                when (ch) {
+                    'A' -> "B"
+                    'B' -> "C"
+                    'C' -> "AB"
+                    else -> throw AssertionError("Unexpected character found: $ch")
+                }
+            }.joinToString("")
+        }
+
+        return words
+    }
+}