Data commit

Task/Calculating-the-value-of-e/Visual-Basic-.NET/calculating-the-value-of-e.vb

@@ -0,0 +1,19 @@
+Imports System, System.Numerics, System.Math, System.Console
+
+Module Program
+    Function CalcE(ByVal nDigs As Integer) As String
+        Dim pad As Integer = Round(Log10(nDigs)), n = 1,
+            f As BigInteger = BigInteger.Pow(10, nDigs + pad), e = f + f
+        Do : n+= 1 : f /= n : e += f : Loop While f > n
+        Return (e / BigInteger.Pow(10, pad + 1)).ToString().Insert(1, ".")
+    End Function
+
+    Sub Main()
+        WriteLine(Exp(1))  '  double precision built-in function
+        WriteLine(CalcE(100))   '  arbitrary precision result
+        Dim st As DateTime = DateTime.Now, qmil As Integer = 250_000,
+            es As String = CalcE(qmil)  '  large arbitrary precision result string
+        WriteLine("{0:n0} digits in {1:n3} seconds.", qmil, (DateTime.Now - st).TotalSeconds)
+        WriteLine("partial: {0}...{1}", es.Substring(0, 46), es.Substring(es.Length - 45))
+    End Sub
+End Module