Data commit

Task/Kaprekar-numbers/Visual-Basic-.NET/kaprekar-numbers.vb

@@ -0,0 +1,51 @@
+Module Module1
+
+    ReadOnly max As ULong = 1000000
+
+    Function Kaprekar(n As ULong) As Boolean
+        If n = 1 Then Return True
+
+        Dim sq = n * n
+        Dim sq_str = Str(sq)
+        Dim l = Len(sq_str)
+
+        For x = l - 1 To 1 Step -1
+            If sq_str(x) = "0" Then
+                l = l - 1
+            Else
+                Exit For
+            End If
+        Next
+
+        For x = 1 To l - 1
+            Dim p2 = Val(Mid(sq_str, x + 1))
+            If p2 > n Then
+                Continue For
+            End If
+            Dim p1 = Val(Left(sq_str, x))
+            If p1 > n Then Return False
+            If (p1 + p2) = n Then Return True
+        Next
+
+        Return False
+    End Function
+
+    Sub Main()
+        Dim count = 0
+
+        Console.WriteLine("Kaprekar numbers below 10000")
+
+        For n = 1 To max - 1
+            If Kaprekar(n) Then
+                count = count + 1
+                If n < 10000 Then
+                    Console.WriteLine("{0,2} {1,4}", count, n)
+                End If
+            End If
+        Next
+
+        Console.WriteLine()
+        Console.WriteLine("{0} numbers below {1} are kaprekar numbers", count, max)
+    End Sub
+
+End Module