VBA Sort RossetaCode

Public Sub Quick(a() As Variant, last As Integer)
' quicksort a Variant array (1-based, numbers or strings)
Dim aLess() As Variant
Dim aEq() As Variant
Dim aGreater() As Variant
Dim pivot As Variant
Dim naLess As Integer
Dim naEq As Integer
Dim naGreater As Integer
 
If last > 1 Then
    'choose pivot in the middle of the array
    pivot = a(Int((last + 1) / 2))
    'construct arrays
    naLess = 0
    naEq = 0
    naGreater = 0
    For Each el In a()
      If el > pivot Then
        naGreater = naGreater + 1
        ReDim Preserve aGreater(1 To naGreater)
        aGreater(naGreater) = el
      ElseIf el < pivot Then
        naLess = naLess + 1
        ReDim Preserve aLess(1 To naLess)
        aLess(naLess) = el
      Else
        naEq = naEq + 1
        ReDim Preserve aEq(1 To naEq)
        aEq(naEq) = el
      End If
    Next
    'sort arrays "less" and "greater"
    Quick aLess(), naLess
    Quick aGreater(), naGreater
    'concatenate
    P = 1
    For i = 1 To naLess
      a(P) = aLess(i): P = P + 1
    Next
    For i = 1 To naEq
      a(P) = aEq(i): P = P + 1
    Next
    For i = 1 To naGreater
      a(P) = aGreater(i): P = P + 1
    Next
End If
End Sub
 
Public Sub QuicksortTest()
Dim a(1 To 26) As Variant
 
 'populate a with numbers in descending order, then sort
 For i = 1 To 26: a(i) = 26 - i: Next
 Quick a(), 26
 For i = 1 To 26: Debug.Print a(i);: Next
 Debug.Print
 'now populate a with strings in descending order, then sort
 For i = 1 To 26: a(i) = Chr$(Asc("z") + 1 - i) & "-stuff": Next
 Quick a(), 26
 For i = 1 To 26: Debug.Print a(i); " ";: Next
 Debug.Print
End Sub

Source: rosettacode.org

Similar codes

0 vote227 views1 answer
Vba copy file
VBA
0 vote214 views1 answer
Vbnet get file name from path
VBA
0 vote236 views1 answer
Vba array dimensions
VBA
0 vote213 views1 answer
Replace spaces with underscores vbnet
VBA
0 vote240 views1 answer
Pivot data source not accepting table named range vba
VBA
1 vote165 views1 answer
Vba Remove Case Sensitivity
VBA
2 votes220 views2 answers
Vba code to remove duplicates from a column
VBA
2 votes224 views1 answer
Vba ado ace sql alias ignored for calculated column
VBA
0 vote235 views1 answer
Build an index all files of a FTP site
VBA
1 vote237 views1 answer
Excel vba How to determine if a date falls on the weekend?
VBA