Initial data commit

Task/Hailstone-sequence/C-sharp/hailstone-sequence-1.cs

@@ -0,0 +1,44 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace Hailstone
+{
+    class Program
+    {
+        public static List<int> hs(int n,List<int> seq)
+        {
+            List<int> sequence = seq;
+            sequence.Add(n);
+            if (n == 1)
+            {
+                return sequence;
+            }else{
+                int newn = (n % 2 == 0) ? n / 2 : (3 * n) + 1;
+                return hs(newn, sequence);
+            }
+        }
+
+        static void Main(string[] args)
+        {
+            int n = 27;
+            List<int> sequence = hs(n,new List<int>());
+            Console.WriteLine(sequence.Count + " Elements");
+            List<int> start = sequence.GetRange(0, 4);
+            List<int> end = sequence.GetRange(sequence.Count - 4, 4);
+            Console.WriteLine("Starting with : " + string.Join(",", start) + " and ending with : " + string.Join(",", end));
+            int number = 0, longest = 0;
+            for (int i = 1; i < 100000; i++)
+            {
+                int count = (hs(i, new List<int>())).Count;
+                if (count > longest)
+                {
+                    longest = count;
+                    number = i;
+                }
+            }
+            Console.WriteLine("Number < 100000 with longest Hailstone seq.: " + number + " with length of " + longest);
+       }
+    }
+}

Task/Hailstone-sequence/C-sharp/hailstone-sequence-2.cs

@@ -0,0 +1,42 @@
+using System;
+using System.Collections.Generic;
+
+namespace ConsoleApplication1
+{
+    class Program
+    {
+        public static void Main()
+        {
+            int longestChain = 0, longestNumber = 0;
+
+            var recursiveLengths = new Dictionary<int, int>();
+
+            const int maxNumber = 100000;
+
+            for (var i = 1; i <= maxNumber; i++)
+            {
+                var chainLength = Hailstone(i, recursiveLengths);
+                if (longestChain >= chainLength)
+                    continue;
+
+                longestChain = chainLength;
+                longestNumber = i;
+            }
+            Console.WriteLine("max below {0}: {1} ({2} steps)", maxNumber, longestNumber, longestChain);
+        }
+
+        private static int Hailstone(int num, Dictionary<int, int> lengths)
+        {
+            if (num == 1)
+                return 1;
+
+            while (true)
+            {
+                if (lengths.ContainsKey(num))
+                    return lengths[num];
+
+                lengths[num] = 1 + ((num%2 == 0) ? Hailstone(num/2, lengths) : Hailstone((3*num) + 1, lengths));
+            }
+        }
+    }
+}