update

Task/Executable-library/00DESCRIPTION

@@ -6,10 +6,10 @@ The general idea behind an executable library is to create a library that when u
 
 * The library, when executed directly should satisfy the remaining requirements of the [[Hailstone sequence]] task:
 :: 2.  Use the routine to show that the hailstone sequence for the number 27 has 112 elements starting with 27, 82, 41, 124 and ending with 8, 4, 2, 1
-:: 3.  Show the number less than 100,000 which has the longest hailstone sequence together with that sequences length.
+:: 3.  Show the number less than 100,000 which has the longest hailstone sequence together with that sequence's length.
 
 * Create a second executable to calculate the following:
-** Use the libraries hailstone function, in the standard manner, (or document how this use deviates from standard use of a library), together with extra code in this executable, to find the hailstone length returned most often for 1 ≤ n < 100,000.
+** Use the library's hailstone function, in the standard manner, (or document how this use deviates from standard use of a library), together with extra code in this executable, to find the hailstone length returned most often for 1 ≤ n < 100,000.
 
 * Explain any extra setup/run steps needed to complete the task.
 

Task/Executable-library/NetRexx/executable-library.netrexx

@@ -0,0 +1,35 @@
+/* NetRexx */
+options replace format comments java crossref symbols nobinary
+
+import RHailstoneSequence
+
+runSample(arg)
+return
+
+-- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+method runSample(arg) private static
+  parse arg beginNum endNum .
+  if beginNum = '' | beginNum = '.' then beginNum = 1
+  if endNum   = '' | endNum   = '.' then endNum   = 100000
+  if beginNum > endNum then signal IllegalArgumentException('Gronk!')
+
+  -- collect sequences
+  hailstones = 0
+  loop hn = beginNum while hn < endNum
+    hslist = RHailstoneSequence.hailstone(hn)
+    hscount = hslist.words()
+    hailstones[hscount] = hailstones[hscount] + 1
+    end hn
+
+  -- locate most common
+  mostOftenNum = 0
+  mostOftenCount = 0
+  loop hn = beginNum while hn < endNum
+    if hailstones[hn] > mostOftenCount then do
+      mostOftenCount = hailstones[hn]
+      mostOftenNum   = hn
+      end
+    end hn
+
+  say 'The length of hailstone sequence that is most common in the range' beginNum '<= N <' endNum 'is' mostOftenNum'. It occurs' mostOftenCount 'times.'
+  return

Task/Executable-library/Racket/executable-library-1.rkt

@@ -0,0 +1,21 @@
+#lang racket
+
+(provide hailstone)
+(define hailstone
+  (let ([t (make-hasheq)])
+    (hash-set! t 1 '(1))
+    (λ(n) (hash-ref! t n
+            (λ() (cons n (hailstone (if (even? n) (/ n 2) (+ (* 3 n) 1)))))))))
+
+(module+ main
+  (define h27 (hailstone 27))
+  (printf "h(27) = ~s, ~s items\n"
+          `(,@(take h27 4) ... ,@(take-right h27 4))
+          (length h27))
+  (define N 100000)
+  (define longest
+    (for/fold ([m #f]) ([i (in-range 1 (add1 N))])
+      (define h (hailstone i))
+      (if (and m (> (cdr m) (length h))) m (cons i (length h)))))
+  (printf "for x<=~s, ~s has the longest sequence with ~s items\n"
+          N (car longest) (cdr longest)))

Task/Executable-library/Racket/executable-library-2.rkt

@@ -0,0 +1,12 @@
+#lang racket
+(require "hs.rkt")
+(define N 100000)
+(define t (make-hasheq))
+(define best
+  (for/fold ([best #f]) ([i (in-range 1 (add1 N))])
+    (define len (length (hailstone i)))
+    (define freq (add1 (hash-ref t len 0)))
+    (hash-set! t len freq)
+    (if (and best (> (car best) freq)) best (cons freq len))))
+(printf "Most frequent sequence length for x<=~s: ~s, appearing ~s times\n" N
+        (cdr best) (car best))