Data commit

Task/Bell-numbers/Visual-Basic-.NET/bell-numbers.vb

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+Imports System.Numerics
+Imports System.Runtime.CompilerServices
+
+Module Module1
+
+    <Extension()>
+    Sub Init(Of T)(array As T(), value As T)
+        If IsNothing(array) Then Return
+        For i = 0 To array.Length - 1
+            array(i) = value
+        Next
+    End Sub
+
+    Function BellTriangle(n As Integer) As BigInteger()()
+        Dim tri(n - 1)() As BigInteger
+        For i = 0 To n - 1
+            Dim temp(i - 1) As BigInteger
+            tri(i) = temp
+            tri(i).Init(0)
+        Next
+        tri(1)(0) = 1
+        For i = 2 To n - 1
+            tri(i)(0) = tri(i - 1)(i - 2)
+            For j = 1 To i - 1
+                tri(i)(j) = tri(i)(j - 1) + tri(i - 1)(j - 1)
+            Next
+        Next
+        Return tri
+    End Function
+
+    Sub Main()
+        Dim bt = BellTriangle(51)
+        Console.WriteLine("First fifteen Bell numbers:")
+        For i = 1 To 15
+            Console.WriteLine("{0,2}: {1}", i, bt(i)(0))
+        Next
+        Console.WriteLine("50: {0}", bt(50)(0))
+        Console.WriteLine()
+        Console.WriteLine("The first ten rows of Bell's triangle:")
+        For i = 1 To 10
+            Dim it = bt(i).GetEnumerator()
+            Console.Write("[")
+            If it.MoveNext() Then
+                Console.Write(it.Current)
+            End If
+            While it.MoveNext()
+                Console.Write(", ")
+                Console.Write(it.Current)
+            End While
+            Console.WriteLine("]")
+        Next
+    End Sub
+
+End Module