CDE

Task/Executable-library/REXX/executable-library-3.rexx

@@ -0,0 +1,15 @@
+/*REXX pgm finds the most common (popular) hailstone sequence length.   */
+parse arg z .;  if z=='' then z=99999  /*get the optional first argument*/
+!.=0
+w=0;          do j=1  for z            /*═════════════task 4════════════*/
+              #=words(hailstone(j))    /*obtain hailstone sequence count*/
+              !.# = !.# + 1            /*add unity to popularity count. */
+              end   /*j*/
+occ=0;  p=0
+              do k=1  for z
+              if !.k>occ  then do;  occ=!.k;  p=k;  end
+              end   /*p*/
+
+say '(between 1──►'z") "  p,
+' is the most common hailstone sequence length  (with' occ "occurrences)."
+                                       /*stick a fork in it, we're done.*/