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Hey Guys,
I have a big problem here. I need a sorting algorithm that is VERY quick and can keep track of a particular row. I am using a quick sort algorithm now but it doesn't work right. when it comes accross two values that are the same on alternate calls it flips the two around.
Here's my example
On the first pass (pass = 0) all the records show up unsorted. On every pass after that they are sorted but every other sorting pass causes depth numbers that are the same to trade spaces. In other words, I dont want that!
How can I prevent depth values that are the same from swapping with each other? It's probably very simple but I havn't a clue were to begin looking.
Thanks for any help guys!
------------------
Cheers!
[This message has been edited by mark smit (edited June 01, 2001).]
I have a big problem here. I need a sorting algorithm that is VERY quick and can keep track of a particular row. I am using a quick sort algorithm now but it doesn't work right. when it comes accross two values that are the same on alternate calls it flips the two around.
Here's my example
Code:
#compile exe
#include "win32api.inc"
type CRecord
lDepth as long
lData as long
end type
function SortRecords(Record() as CRecord,byval lRow as long,byval l as long,byval r as long) as long
dim lDepth as long
dim i as long
dim j as long
lDepth = Record((l+r)\2).lDepth
i = l
j = r
while (i <= j)
while (Record(i).lDepth < lDepth) and (i < r):incr i:wend
while (Record(j).lDepth > lDepth) and (j > l):decr j:wend
if (i <= j) then
'Track row number
if (lRow = i) then
lRow = j
elseif (lRow = j) then
lRow = i
end if
'Swap records
swap Record(i),Record(j)
incr i
decr j
end if
wend
if (l < j) then lRow = SortRecords(Record(),lRow,l,j)
if (i < r) then lRow = SortRecords(Record(),lRow,i,r)
'Return row number
function = lRow
end function
function pbmain as long
dim Record(10) as CRecord
dim strMsg as string
dim lResult as long
dim lIndex as long
dim lPass as long
dim lRow as long
randomize 1'Make sure we all see the same "random" numbers
'Generate random data
for lIndex = 0 to 10
Record(lIndex).lDepth = rnd(0,5)
Record(lIndex).lData = lIndex
next
lPass = 0'First pass means we didn't sort yet
lRow = 2'Select row 2
do
'Build dialog message
strMsg = format$(lRow,"Row = #")
strMsg = (strMsg & format$(Record(lRow).lDepth," Depth = #"))
strMsg = (strMsg & $CRLF & $CRLF)
for lIndex = 0 to 10
strMsg = (strMsg & str$(Record(lIndex).lDepth) & str$(Record(lIndex).lData) & $CRLF)
next
'Display results and check for cancel
lResult = msgbox(strMsg,%MB_OKCANCEL,format$(lPass,"Pass #"))
if (lResult = %IDCANCEL) then exit loop
'Sort records
lRow = SortRecords(Record(),lRow,0,10)
incr lPass
loop
end function
On the first pass (pass = 0) all the records show up unsorted. On every pass after that they are sorted but every other sorting pass causes depth numbers that are the same to trade spaces. In other words, I dont want that!
How can I prevent depth values that are the same from swapping with each other? It's probably very simple but I havn't a clue were to begin looking.
Thanks for any help guys!
------------------
Cheers!
[This message has been edited by mark smit (edited June 01, 2001).]
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