Hi Again,
This is the quick sort routine for a 2 dimensional array. It also has a
one dimensional array commented out; note: dividing by half does not work, a
random number does.
So, here you have the Quick Sort routine that can be changed in the
calling list at the name to a one dimensional array and what you need along
with the call to quicksort at the end which has to match the prototype at
the top.
So comment out the 2 dimensional stuff and uncomment the original one
dimensional and you have the quick sort both ways.
Sincerely
Bruce
' *******************************************************
' Recursively perform the actual quicksort algorithm.
' Do a 2 dimensional column sort where first column is row value and second
element is column element value.
' The column dimension allows many values in list, such as name, date,
version, size, and and thing, like the UnInstall program.
' *******************************************************
Sub Quicksort (List, min, max, sortCol, maxCols)
Dim midRow(), midValue, hi, lo, i
ReDim midRow(1, maxCols)
' If the list has no more than 1 element, it's sorted.
If min >= max Then Exit Sub
' Pick a dividing item.
' i = Int( (max - min) /2)
' i = Int( (max - min + 1) * Rnd + min)
i = Int( (max - min) * Rnd + min)
midValue = List( i, sortCol)
assignRow midRow, 0, List, i, maxCols
' Swap it to the front so we can find it easily.
' List( i) = List( min)
assignRow List, i, List, min, maxCols
' Move the items smaller than this into the left half of the list. Move the
others into the right.
lo = min
hi = max
Do
' Look down from hi for a value < midValue.
Do While List( hi, sortCol) >= midValue
hi = hi - 1
If hi <= lo Then Exit Do
Loop
If hi <= lo Then
' List( lo) = midValue
assignRow List, lo, midRow, 0, maxCols
Exit Do
End If
' Swap the lo and hi values.
'List( lo) = List( hi)
assignRow List, lo, List, hi, maxCols
' Look up from lo for a value >= midValue.
lo = lo + 1
Do While List( lo, sortCol) < midValue
lo = lo + 1
If lo >= hi Then Exit Do
Loop
If lo >= hi Then
lo = hi
'List( hi) = midValue
assignRow List, hi, midRow, 0, maxCols
Exit Do
End If
' Swap the lo and hi values.
'List(hi) = List(lo)
assignRow List, hi, List, lo, maxCols
Loop
' Sort the two sublists
Quicksort List, min, lo - 1, sortCol, maxCols
Quicksort List, lo + 1, max, sortCol, maxCols
End Sub
Sub assignRow( destinationList, destinationRow, sourceList, sourceRow,
maxCol)
' Assign source list row to destination list row.
Dim c
For c = 0 to maxCol
destinationList( destinationRow, c) = sourceList( sourceRow, c)
Next
End Sub
Sub swapListRows( row1, row2, maxCol)
' Swap the 2 list rows.
Dim c, temp
For c = 0 to maxCol
temp = list( row1, c)
list( row1, c) = list( row2, c)
list( row2, c) = temp
Next
End Sub
