Data commit

Task/Average-loop-length/VBScript/average-loop-length.vb

@@ -0,0 +1,48 @@
+Const MAX = 20
+Const ITER = 100000
+
+Function expected(n)
+  Dim sum
+  ni=n
+  For i = 1 To n
+    sum = sum + fact(n) / ni / fact(n-i)
+    ni=ni*n
+  Next
+  expected = sum
+End Function
+
+Function test(n )
+  Dim coun,x,bits
+  For i = 1 To ITER
+    x = 1
+    bits = 0
+    Do While Not bits And x
+      count = count + 1
+      bits = bits Or x
+      x =shift(Int(n * Rnd()))
+    Loop
+  Next
+  test = count / ITER
+End Function
+
+'VBScript formats numbers but does'nt align them!
+function rf(v,n,s) rf=right(string(n,s)& v,n):end function
+
+'some precalculations to speed things up...
+dim fact(20),shift(20)
+fact(0)=1:shift(0)=1
+for i=1 to 20
+  fact(i)=i*fact(i-1)
+  shift(i)=2*shift(i-1)
+next
+
+Dim n
+Wscript.echo "For " & ITER &" iterations"
+Wscript.Echo " n     avg.     exp.   (error%)"
+Wscript.Echo "==   ======   ======  =========="
+For n = 1 To MAX
+  av = test(n)
+  ex = expected(n)
+  Wscript.Echo rf(n,2," ")& "  "& rf(formatnumber(av, 4),7," ") & "   "& _
+  rf(formatnumber(ex,4),6," ")& "  ("& rf(Formatpercent(1 - av / ex,4),8," ") & ")"
+Next