Initial data commit

Task/Permutations/C-sharp/permutations-3.cs

@@ -0,0 +1,31 @@
+public class Permutations<T>
+{
+    public static System.Collections.Generic.IEnumerable<T[]> AllFor(T[] array)
+    {
+        if (array == null || array.Length == 0)
+        {
+            yield return new T[0];
+        }
+        else
+        {
+            for (int pick = 0; pick < array.Length; ++pick)
+            {
+                T item = array[pick];
+                int i = -1;
+                T[] rest = System.Array.FindAll<T>(
+                    array, delegate(T p) { return ++i != pick; }
+                );
+                foreach (T[] restPermuted in AllFor(rest))
+                {
+                    i = -1;
+                    yield return System.Array.ConvertAll<T, T>(
+                        array,
+                        delegate(T p) {
+                            return ++i == 0 ? item : restPermuted[i - 1];
+                        }
+                    );
+                }
+            }
+        }
+    }
+}