Data update

Task/Padovan-sequence/C-sharp/padovan-sequence.cs

@@ -0,0 +1,74 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+
+public static class Padovan
+{
+    private static readonly List<int> recurrences = new List<int>();
+    private static readonly List<int> floors = new List<int>();
+    private const double PP = 1.324717957244746025960908854;
+    private const double SS = 1.0453567932525329623;
+
+    public static void Main(string[] args)
+    {
+        for (int i = 0; i < 64; i++)
+        {
+            recurrences.Add(PadovanRecurrence(i));
+            floors.Add(PadovanFloor(i));
+        }
+
+        Console.WriteLine("The first 20 terms of the Padovan sequence:");
+        recurrences.GetRange(0, 20).ForEach(term => Console.Write(term + " "));
+        Console.WriteLine(Environment.NewLine);
+
+        Console.WriteLine("Recurrence and floor functions agree for first 64 terms? " + recurrences.SequenceEqual(floors));
+        Console.WriteLine(Environment.NewLine);
+
+        List<string> words = CreateLSystem();
+
+        Console.WriteLine("The first 10 terms of the L-system:");
+        words.GetRange(0, 10).ForEach(term => Console.Write(term + " "));
+        Console.WriteLine(Environment.NewLine);
+
+        Console.Write("Length of first 32 terms produced from the L-system match Padovan sequence? ");
+        List<int> wordLengths = words.Select(s => s.Length).ToList();
+        Console.WriteLine(wordLengths.SequenceEqual(recurrences.GetRange(0, 32)));
+    }
+
+    private static int PadovanRecurrence(int n)
+    {
+        if (n <= 2)
+            return 1;
+        return recurrences[n - 2] + recurrences[n - 3];
+    }
+
+    private static int PadovanFloor(int n)
+    {
+        return (int)Math.Floor(Math.Pow(PP, n - 1) / SS + 0.5);
+    }
+
+    private static List<string> CreateLSystem()
+    {
+        List<string> words = new List<string>();
+        string text = "A";
+
+        while (words.Count < 32)
+        {
+            words.Add(text);
+            char[] textChars = text.ToCharArray();
+            text = "";
+            foreach (char ch in textChars)
+            {
+                text += ch switch
+                {
+                    'A' => "B",
+                    'B' => "C",
+                    'C' => "AB",
+                    _ => throw new InvalidOperationException("Unexpected character found: " + ch),
+                };
+            }
+        }
+
+        return words;
+    }
+}