ExcelBanter - List all possible combinations

Following is a macro based solution form Myrna Larson (Microsoft MVP) on
permutation and combinations using EXCEL.

1. It allows Combinations or Permutations.
2. The macro handles numbers, text strings, words (e.g. names of people) or
symbols.
3. The combinations are written to a new sheet.
4. Results are returned almost instantaneously.

Setup:
In sheet1:
Cell A1, put €œC€ (Combinations) or €œP€ (Permutations). (C in your case)
Cell A2, put the number of items in the subset €“ (10 in your case).
Cells A3 down, your list. - (Type 1 in A3 2 in A4 & 3 in A5)
Run the macro

HERE IS THE CODE:

Option Explicit

Dim vAllItems As Variant
Dim Buffer() As String
Dim BufferPtr As Long
Dim Results As Worksheet
'
' Myrna Larson, July 25, 2000, Microsoft.Public.Excel.Misc

Sub ListPermutationsOrCombinations()
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

Worksheets("Sheet1").Range("A1").Select
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

"Spencer Hutton" wrote:

Is there a way to use VBA or a formula to return a list of integers from 1 to
10 starting in cell A1. my goal is to have this loop list all possible
combinations of say any 3 numbers from 1 to 10. like 123, 132, 231, 213,
312, 321, 456, 465, etc...