Module Module1


    Public Sub process(ByVal subset As Array)
        Console.WriteLine(subset.ToString)
    End Sub




    Public Sub processLargerSubsets(ByRef xset As Array, ByRef subset As Array, ByVal subsetSize As Integer, ByVal nextIndex As Integer)


        If subsetSize = subset.Length Then
            process(subset)
        Else
            For j As Integer = nextIndex To xset.Length - 1
                subset(subsetSize) = xset(j)
                processLargerSubsets(xset, subset, subsetSize + 1, j + 1)
            Next j
        End If


    End Sub

   
    Public Sub processSubsets(ByRef xset As Array, ByVal k As Integer)
        Dim subset As Array = Array.CreateInstance(GetType(Integer), k)
        processLargerSubsets(xset, subset, 0, 0)
    End Sub




    Sub Main()

        Dim nset As Array = Array.CreateInstance(GetType(Integer), 20)
        For k As Integer = 0 To 19
            nset(k) = k + 1
        Next k
        processSubsets(nset, 3)

    End Sub


End Module