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Combinations

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João Veríssimo

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Jan 18, 2003, 9:08:57 AM1/18/03
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Hi!

I am trying to think how VBA/Excel could list all possible combinations /
arrangements of a set of elements, but I couldn´t manage it yet.

I think Myrna Larson had written some code for this, and that it was posted
in this newsgroup.

Notice that i am not talking about permutations, but combinations of a
(smaller) number of elements from a set.

Any one can do this?

Tham you very much,
--
João Veríssimo (joao_ve...@clix.pt)

Ken Wright

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Jan 18, 2003, 9:22:59 AM1/18/03
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Myrna's code you want, Myrna's code you got!!


Written and Posted by Myrna Larson:

Option Explicit

Dim vAllItems As Variant
Dim Buffer() As String
Dim BufferPtr As Long
Dim Results As Worksheet
'
' Posted by Myrna Larson
' July 25, 2000
' Microsoft.Public.Excel.Misc
' Subject: Combin
'
'
'Since you asked, here it is. It is generic, i.e. it isn't written
specifically
'for a given population and set size, as yours it. It will do permutations
or
'combinations. It uses a recursive routine to generate the subsets, one
routine
'for combinations, a different one for permutations.

'To use it, you put the letter C or P (for combinations or permutations) in
a
'cell. The cell below that contains the number of items in a subset. The
cells
'below are a list of the items that make up the population. They could be
'numbers, letters and symbols, or words, etc.

'You select the top cell, or the entire range and run the sub. The subsets
are
'written to a new sheet in the workbook.
'
'

Sub ListPermutations()
Dim Rng As Range
Dim PopSize As Integer
Dim SetSize As Integer
Dim Which As String
Dim N As Double
Const BufferSize As Long = 4096

Set Rng = Selection.Columns(1).Cells
If Rng.Cells.Count = 1 Then
Set Rng = Range(Rng, Rng.End(xlDown))
End If

PopSize = Rng.Cells.Count - 2
If PopSize < 2 Then GoTo DataError

SetSize = Rng.Cells(2).Value
If SetSize > PopSize Then GoTo DataError

Which = UCase$(Rng.Cells(1).Value)
Select Case Which
Case "C"
N = Application.WorksheetFunction.Combin(PopSize, SetSize)
Case "P"
N = Application.WorksheetFunction.Permut(PopSize, SetSize)
Case Else
GoTo DataError
End Select
If N > Cells.Count Then GoTo DataError

Application.ScreenUpdating = False

Set Results = Worksheets.Add

vAllItems = Rng.Offset(2, 0).Resize(PopSize).Value
ReDim Buffer(1 To BufferSize) As String
BufferPtr = 0

If Which = "C" Then
AddCombination PopSize, SetSize
Else
AddPermutation PopSize, SetSize
End If
vAllItems = 0

Application.ScreenUpdating = True
Exit Sub

DataError:
If N = 0 Then
Which = "Enter your data in a vertical range of at least 4 cells. " _
& String$(2, 10) _
& "Top cell must contain the letter C or P, 2nd cell is the number " _
& "of items in a subset, the cells below are the values from which " _
& "the subset is to be chosen."

Else
Which = "This requires " & Format$(N, "#,##0") & _
" cells, more than are available on the worksheet!"
End If
MsgBox Which, vbOKOnly, "DATA ERROR"
Exit Sub
End Sub

Private Sub AddPermutation(Optional PopSize As Integer = 0, _
Optional SetSize As Integer = 0, _
Optional NextMember As Integer = 0)

Static iPopSize As Integer
Static iSetSize As Integer
Static SetMembers() As Integer
Static Used() As Integer
Dim i As Integer

If PopSize <> 0 Then
iPopSize = PopSize
iSetSize = SetSize
ReDim SetMembers(1 To iSetSize) As Integer
ReDim Used(1 To iPopSize) As Integer
NextMember = 1
End If

For i = 1 To iPopSize
If Used(i) = 0 Then
SetMembers(NextMember) = i
If NextMember <> iSetSize Then
Used(i) = True
AddPermutation , , NextMember + 1
Used(i) = False
Else
SavePermutation SetMembers()
End If
End If
Next i

If NextMember = 1 Then
SavePermutation SetMembers(), True
Erase SetMembers
Erase Used
End If

End Sub 'AddPermutation

Private Sub AddCombination(Optional PopSize As Integer = 0, _
Optional SetSize As Integer = 0, _
Optional NextMember As Integer = 0, _
Optional NextItem As Integer = 0)

Static iPopSize As Integer
Static iSetSize As Integer
Static SetMembers() As Integer
Dim i As Integer

If PopSize <> 0 Then
iPopSize = PopSize
iSetSize = SetSize
ReDim SetMembers(1 To iSetSize) As Integer
NextMember = 1
NextItem = 1
End If

For i = NextItem To iPopSize
SetMembers(NextMember) = i
If NextMember <> iSetSize Then
AddCombination , , NextMember + 1, i + 1
Else
SavePermutation SetMembers()
End If
Next i

If NextMember = 1 Then
SavePermutation SetMembers(), True
Erase SetMembers
End If

End Sub 'AddCombination

Private Sub SavePermutation(ItemsChosen() As Integer, _
Optional FlushBuffer As Boolean = False)

Dim i As Integer, sValue As String
Static RowNum As Long, ColNum As Long

If RowNum = 0 Then RowNum = 1
If ColNum = 0 Then ColNum = 1

If FlushBuffer = True Or BufferPtr = UBound(Buffer()) Then
If BufferPtr > 0 Then
If (RowNum + BufferPtr - 1) > Rows.Count Then
RowNum = 1
ColNum = ColNum + 1
If ColNum > 256 Then Exit Sub
End If

Results.Cells(RowNum, ColNum).Resize(BufferPtr, 1).Value _
= Application.WorksheetFunction.Transpose(Buffer())
RowNum = RowNum + BufferPtr
End If

BufferPtr = 0
If FlushBuffer = True Then
Erase Buffer
RowNum = 0
ColNum = 0
Exit Sub
Else
ReDim Buffer(1 To UBound(Buffer))
End If

End If

'construct the next set
For i = 1 To UBound(ItemsChosen)
sValue = sValue & ", " & vAllItems(ItemsChosen(i), 1)
Next i

'and save it in the buffer
BufferPtr = BufferPtr + 1
Buffer(BufferPtr) = Mid$(sValue, 3)
End Sub 'SavePermutation


--
Regards
Ken....................... Win XP / XL2K & XLXP

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"João Veríssimo" <joao_ve...@clix.pt> wrote in message
news:MfdW9.1812$9x.11...@newsserver.ip.pt...

srif...@gmail.com

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Feb 8, 2016, 7:07:06 AM2/8/16
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hi sir i am from india
i am doing project in vba.
i want to known how to create a combinations using text/words like aaa,bbb and numbers?

can u help me?
\

nat...@gmail.com

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Jun 3, 2020, 6:05:05 AM6/3/20
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Thank you very much everyone - Myrna Larson especially.

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