;------------------------------------------------------------------------------------------------------------------------------------------
#DefineFunction udfArrayShellSort (arrArray)
If !ArrInfo (arrArray, -1) Then Return ArrDimension (0) ; Invalid input array, return empty valid dim-0 array.
If ArrInfo (arrArray, 0) != 1 Then Return ArrDimension (0) ; Only dim-1 array allowed, return empty valid dim-0 array.
intElements = ArrInfo (arrArray, 1)
If intElements == 0 Then Return ArrDimension (0) ; Input array has no elements, return empty valid dim-0 array.
If intElements == 1 Then Return arrArray ; Input array has only one element, return the input array.
intHigh = intElements - 1
intLow = 0
intStart = Int (Floor (LogE (Max (intHigh, 2) - 1) / LogE (2)))
For intI = intStart To intLow By -1
   intStep = Int (Exp (intI * LogE (2)))
   For intK = intStep To intHigh
      anyValue = arrArray [intK]
      intZ = intK - intStep
      intDone = (anyValue >= arrArray [intZ])
      While !intDone
         arrArray [intZ + intStep] = arrArray [intZ]
         intZ = intZ - intStep
         intDone = 1
         If intZ > 0 Then intDone = (anyValue >= arrArray [intZ])
      EndWhile
      arrArray [intZ + intStep] = anyValue
   Next
Next
Return arrArray
;..........................................................................................................................................
; Note:
; Using code fragment (B) instead of fragment (A) in the inner While loop
; tunes up the performance speed of this ShellSort implementation of arrBout >=10 Pct.!
; (A)
;         If (iZ>0)
;            intDone = (aA>=arrArray [iZ])
;         Else
;            intDone = 1
;         EndIf
; (B)
;         intDone = 1
;         If (iZ>0) Then intDone = (aA>=arrArray [iZ])
;..........................................................................................................................................
; ShellSort, developed by Donald L. Shell, is a non-stable in-place sort.
; ShellSort improves on the efficiency of insertion sort by quickly shifting values to their destination.
; For further reading, consult:
; Knuth, Donald. E. [1998]. The Art of Computer Programming, Volume 3,
; Sorting and Searching. Addison-Wesley, Reading, Massachusetts.
;..........................................................................................................................................
#EndFunction
;------------------------------------------------------------------------------------------------------------------------------------------

;----------------------------------------------------------------------------------------------------------------------
#DefineFunction udfArrayItemize (arrArray, strDelimiter)
If !ArrInfo (arrArray, -1) Then Return "" ; No array.
If !ArrInfo (arrArray, 6) Then Return "" ; No elements.
If ArrInfo (arrArray, 0) > 1 Then Return "" ; Too much dimensions.
strItemList = ""
intHigh = Max (ArrInfo (arrArray, 1) - 1, 0)
intLow = 0
For intElem = intLow To intHigh
   If !!VarType (arrArray [intElem])
      strItemList = ItemInsert (arrArray [intElem], -1, strItemList, strDelimiter)
   Else
      strItemList = ItemInsert ("", -1, strItemList, strDelimiter)
   EndIf
Next
Return strItemList
;----------------------------------------------------------------------------------------------------------------------
; This UDF "udfArrayItemize" converts a given dim-1 array into an itemlist
; with each item separated by delimiter character.
;
; Example: strMyItemList = udfArrayItemize (arrMyArray, @TAB)
; Creates an itemList from array.
;
; Note:
; This UDF supports only dim-1 array.
; An array element which is not initialized has a Vartype=0 (undefined).
; Therefore an empty item will be appended to target itemlist.
;
; Detlev Dalitz.20020718.20090508.
;----------------------------------------------------------------------------------------------------------------------
#EndFunction
;----------------------------------------------------------------------------------------------------------------------


; Test.

strMsgTitle = "Demo: udfArrayShellSort (arrArray)"
strMsgText = ""

strDelimiter = ","
strItemList = "22,q,w,e,r,t,T,999,a,s,d,f,1,/z,B5,-196" ; 16 Items.

arrA = Arrayize (strItemList, strDelimiter)
arrB = Arrayize (strItemList, strDelimiter)

arrB = udfArrayShellSort (arrB)

strMsgText = strMsgText : "Array A: " : @LF : udfArrayItemize (arrA, strDelimiter) : @LF : @LF ; "22,q,w,e,r,t,T,999,a,s,d,f,1,/z,B5,-196"
strMsgText = strMsgText : "Array B sorted: " : @LF : udfArrayItemize (arrB, strDelimiter) : @LF : @LF ; "/z,-196,1,22,999,a,B5,d,e,f,q,r,s,t,T,w"

Message (strMsgTitle, strMsgText)

Exit