Time for an 2014 update…

Task/Average-loop-length/D/average-loop-length.d

@@ -1,6 +1,6 @@
 import std.stdio, std.random, std.math, std.algorithm, std.range;
 
-real analytical(in int n) /*pure nothrow*/ {
+real analytical(in int n) pure nothrow {
     real total = 0.0;
     foreach (immutable k; 1 .. n + 1) {
         immutable x = reduce!q{a * b}(1.0L, iota(n - k + 1, n + 1))

Task/Average-loop-length/Liberty-BASIC/average-loop-length.liberty

@@ -0,0 +1,36 @@
+MAXN = 20
+TIMES = 10000'00
+
+'t0=time$("ms")
+FOR n = 1 TO MAXN
+    avg = FNtest(n, TIMES)
+    theory = FNanalytical(n)
+    diff = (avg / theory - 1) * 100
+    PRINT n, avg, theory, using("##.####",diff); "%"
+NEXT
+'t1=time$("ms")
+'print t1-t0; " ms"
+END
+
+function FNanalytical(n)
+    FOR i = 1 TO n
+        s = s+ FNfactorial(n) / n^i / FNfactorial(n-i)
+    NEXT
+    FNanalytical = s
+end function
+
+function FNtest(n, times)
+    FOR i = 1 TO times
+        x = 1 : b = 0
+        WHILE (b AND x) = 0
+            c = c + 1
+            b = b OR x
+            x = 2^int(n*RND(1))
+        WEND
+    NEXT
+    FNtest = c / times
+end function
+
+function FNfactorial(n)
+    IF n=1 OR n=0 THEN FNfactorial=1 ELSE FNfactorial= n * FNfactorial(n-1)
+end function

Task/Average-loop-length/Ruby/average-loop-length.rb

@@ -0,0 +1,23 @@
+class Integer
+  def factorial
+    self == 0 ? 1 : (1..self).inject(:*)
+  end
+end
+
+def rand_until_rep(n)
+  rands = {}
+  loop do r = rand(1..n)
+    return rands.size if rands[r]
+    rands[r] = true
+  end
+end
+
+runs = 1_000_000
+
+puts " n\tavg\texp.\tdiff\n_____________________________"
+(1..20).each do |n|
+  sum_of_runs = runs.times.inject(0){|sum, _| sum += rand_until_rep(n)}
+  avg = sum_of_runs / runs.to_f
+  analytical = (1..n).inject(0){|sum, i| sum += (n.factorial / (n**i).to_f / (n-i).factorial)}
+  puts "%2d %8.4f %8.4f %8.4f" % [n, avg, analytical, (avg/analytical - 1)*100]
+end