Initial data commit

Task/Average-loop-length/Factor/average-loop-length.factor

@@ -0,0 +1,25 @@
+USING: formatting fry io kernel locals math math.factorials
+math.functions math.ranges random sequences ;
+
+: (analytical) ( m n -- x )
+    [ drop factorial ] [ ^ /f ] [ - factorial / ] 2tri ;
+
+: analytical ( n -- x )
+    dup [1,b] [ (analytical) ] with map-sum ;
+
+: loop-length ( n -- x )
+    [ 0 0 1 [ 2dup bitand zero? ] ] dip
+    '[ [ 1 + ] 2dip bitor 1 _ random shift ] while 2drop ;
+
+:: average-loop-length ( n #tests -- x )
+     0 #tests [ n loop-length + ] times #tests / ;
+
+: stats ( n -- avg exp )
+    [ 1,000,000 average-loop-length ] [ analytical ] bi ;
+
+: .line ( n -- )
+    dup stats 2dup / 1 - 100 *
+    "%2d %8.4f %8.4f %6.3f%%\n" printf ;
+
+" n\tavg\texp.\tdiff\n-------------------------------" print
+20 [1,b] [ .line ] each