Sorting

 BBS: Inland Empire Archive
Date: 03-25-93 (14:29)             Number: 338
From: DIK COATES                   Refer#: NONE
  To: ALL                           Recvd: NO  
Subj: Sorting                        Conf: (2) Quik_Bas

- Area: Quik_Bas -------------------------------------------------------------
  Msg#: 290                                          Date: 03-23-93  18:43
  From: Leonard Erwine                               Read: Yes    Replied: No
    To: Daniel Stasinski                             Mark:

  Subj: Re: did i make it up?
___

Yeah, those recursive sorting algorythms can eat up alot of
stack space and also dynamic memory space.  I never did
like shell sorting algorythms anyway.

This shell sort is non-recursive...

'******************************************************* SUBPROGRAM ShellSort
'
'   Procedure uses the Shell-Metzger algorithm for sorting an array of string
'   variables.  Adapted from an article by Donald Shell and disassembled IBM
'   360 machine language.  This sorting algorithm is extremely efficient for
'   sorting small and medium sized arrays.
'
'   PARAMETERS: col0% = number of elements in the string array array$()
'               array$() = string variable array to be sorted.
'   RETURNS:    array$() = sorted string variable array
'
'   Released to Public Domain, 1993, by R.A. Coates
'
SUB ShellSort (col0%, array$())
    col1% = col0%

    WHILE col1%
      col1% = col1% \ 2
      col2% = col0% - col1%

      FOR count% = 1 TO col2%
        col3% = count%
sort1:
        col4% = col3% + col1%
        IF array$(col3%) <= array$(col4%) THEN
          GOTO sort2
        ELSE
          SWAP array$(col3%), array$(col4%)
          col3% = col3% - col1%
        END IF

        IF col3% > 0 THEN
          GOTO sort1
        END IF
sort2:
      NEXT count%
    WEND
END SUB

It was done many years back... and if you ignore the goto's (actually,
they're the fastest way to get somewhere!) you'll find it really quite
fast...

Regards Dik, Oshawa, Canada

... "Hey!  Who took the cork off my lunch??!"
___ Blue Wave/QWK v2.10

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