langs a-z

Task/Forward-difference/Visual-Basic-.NET/forward-difference.visual

@@ -0,0 +1,22 @@
+Module ForwardDifference
+
+    Sub Main()
+        Dim lNum As New List(Of Integer)(New Integer() {90, 47, 58, 29, 22, 32, 55, 5, 55, 73})
+        For i As UInteger = 0 To 9
+            Console.WriteLine(String.Join(" ", (From n In Difference(i, lNum) Select String.Format("{0,5}", n)).ToArray()))
+        Next
+        Console.ReadKey()
+    End Sub
+
+    Private Function Difference(ByVal Level As UInteger, ByVal Numbers As List(Of Integer)) As List(Of Integer)
+        If Level >= Numbers.Count Then Throw New ArgumentOutOfRangeException("Level", "Level must be less than number of items in Numbers")
+
+        For i As Integer = 1 To Level
+            Numbers = (From n In Enumerable.Range(0, Numbers.Count - 1) _
+                       Select Numbers(n + 1) - Numbers(n)).ToList()
+        Next
+
+        Return Numbers
+    End Function
+
+End Module