Produce all combinations from a list of names in excel

问题

So I already have the list of permutations, but i'd like to convert it to combinations. So i have a single list of names "john" "mike" "tom", and these have already been converted to two columns of permutations "john mike" "john tom" "mike john" "mike tom" "tom john" "tom mike", so how would i go about either deleting the redundant permutations to convert it to combinations, or would it be easier to make a new macro to just generate combinations?

So to be clear, the new list i'm looking for would be "john mike" "john tom" "tom mike"

Here is the macro for permutations given to me yesterday (source).

Sub Permutation()

Dim NameList As Variant, NameVal As Variant, NameVal2 As Variant
Dim Iter As Long

NameList = Sheet3.Range("A1:A108").Value

Iter = 1
For Each NameVal In NameList
    For Each NameVal2 In NameList
        If NameVal2 <> NameVal Then
            Range("C" & Iter).Value = NameVal
            Range("D" & Iter).Value = NameVal2
            Iter = Iter + 1
        End If
    Next NameVal2
Next NameVal

End Sub

回答1:

Try this:

Sub NoRepetition()

Dim NameList As Variant, NameVal As Variant, NameVal2 As Variant
Dim Iter As Long, OutputList As Range, NotYet As Boolean

NameList = Range("A1:A5").Value

Iter = 1
For Each NameVal In NameList
    For Each NameVal2 In NameList
        LRow = Range("C" & Rows.Count).End(xlUp).Row
        Set OutputList = Range("C1:C" & LRow)
        NotYet = (Application.CountIf(OutputList, NameVal2) = 0)
        If NameVal2 <> NameVal And NotYet Then
            Range("C" & Iter).Value = NameVal
            Range("D" & Iter).Value = NameVal2
            Iter = Iter + 1
        End If
    Next NameVal2
Next NameVal

End Sub

The additional concept is simple: just add a check to see if the name already exists in the first column. If it does, skip that combination. If not, put it in.

Screenshot:

Let us know if this helps.

来源：https://stackoverflow.com/questions/21630030/produce-all-combinations-from-a-list-of-names-in-excel