I will need QuickSort routine

[stephane fonteyne]

Hi programmers,

Is there someone help me how I can writing the algoritm QuickSort routine?

Greetings,
Stephane


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[Mel Bishop]

Is there some reason you need to write your own QuickSort
routine? PB's Array Sort is just about the fastest sort
you can get on the market and it works with both numeric and
string arrays.


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[Ian Cairns]

Do a search on quicksort. There is at least one in the DOS forum and one in the Source Code forum.

Regards,

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[email protected]

[john writer]

---------Example---------
TYPE sortar
Length AS integer
data as byte
END TYPE

DIM SortArray(1 TO 1000) AS shared sortar
Defint A-Z

QuickSort 1,1000

End


SUB QuickSort (low as integer, high as integer)
IF low < high THEN
IF high - low = 1 THEN
IF SortArray(low).Length > SortArray(high).Length THEN
SWAP SortArray(low), SortArray(high)
END IF
ELSE

' Pick a pivot element at random, then move it to the end:
RandIndex = RandInt(low+0, high+0)
SWAP SortArray(high), SortArray(RandIndex)
Partition = SortArray(high).Length
DO

' Move in from both sides towards the pivot element:
I = low: J = high
DO WHILE (I < J) AND (SortArray(I).Length <= Partition)
I = I + 1
LOOP
DO WHILE (J > I) AND (SortArray(J).Length >= Partition)
J = J - 1
LOOP

' If we haven't reached the pivot element, it means that two
' elements on either side are out of order, so swap them:
IF I < J THEN
SWAP SortArray(I), SortArray(J)
END IF
LOOP WHILE I < J

' Move the pivot element back to its proper place in the array:
SWAP SortArray(I), SortArray(high)

' Recursively call the QuickSort procedure (pass the smaller
' subdivision first to use less stack space):
IF (I - low) < (high - I) THEN
QuickSort low, I - 1
QuickSort I + 1, high
ELSE
QuickSort I + 1, high
QuickSort low, I - 1
END IF
END IF
END IF
END SUB


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[mark smit]

Hello Stephane,

Here is another quicksort...

sub qsort(dat() as long, l as long, r as long)
    local i as long
    local j as long
    local m as long

    i = l
    j = r
    m = dat((l+r)\2)


    while (i<=j)
        while dat(i)<m: incr i: wend
        while dat(j)>m: decr j: wend

        if (i<=j) then
            swap dat(i),dat(j)
            incr i
            decr j
        end if
    wend


    if (l<j) then qsort dat(),l,j
    if (i<r) then qsort dat(),i,r
end sub


called: qsort array(),lbound(array),ubound(array)

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Cheers

[Nedal Qunibi]

hi stephane ,

try this one i think it is the fastest

in DECLAREATION write this( PUBLIC C$),

in the procedure write this.

i = 1
FOR i% = 0 TO 255
C$ = C$ + CHR$(i%)
NEXT i%

AND USE THIS
ARRAY SORT (NAME OF WHAT YOU WANT TO SORT) , COLLATE C$


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