string combinations

[cengineer]

I have the following code to generate combinations of string for a small list and would like to adapt this for a large list of over 300 string words.Can anyone suggest how to alter this code or to use a different method?

Basically what i need to do is generate a list of string words in different combinations. The order does not change based on the list but for example if I had a list of integers: 1,2,3,4,5,6,7,8,9
then the combinations should be

12,23,34,45,56,67,78,89
123,234,345,456,567,678,789
1234,2345,3456,4567,5678,6789
etc all up to the 9

My code works for the list of 5 but if I had a list of 300 strings which I input from a file into an arraylist it takes too long.
here is my initial code with the small list

Imports System
Imports System.IO

Public Class combinations

    Public Shared Sub main()

        Dim myAnimals As String = "cat dog horse ape hen mouse"
        Dim list As New ArrayList
        
       Dim myAnimalCombinations As String() = BuildCombinations(myAnimals)

        For Each combination As String In myAnimalCombinations
            'Look on the Output Tab for the results! 
            Console.WriteLine("(" & combination & ")")
        Next combination

       console.ReadLine()

    End Sub



    Public Shared Function BuildCombinations(ByVal inputString As String) As String()
    
        'Separate the sentence into useable words. 
        Dim wordsArray As String() = inputString.Split(" ".ToCharArray)
       
        'A plase to store the results as we build them 
        Dim returnArray() As String = New String() {""}

        'The 'combination level' that we're up to 
        Dim wordDistance As Integer = 1

        'Go through all the combination levels... 
        For wordDistance = 1 To wordsArray.GetUpperBound(0)
          

            Dim count = wordsArray.GetUpperBound(0)

            'Go through all the words at this combination level... 
            For wordIndex As Integer = 0 To wordsArray.GetUpperBound(0) - wordDistance
               'Get the first word of this combination level 
                Dim combination As New System.Text.StringBuilder(wordsArray(wordIndex))
                             'And all all the remaining words a this combination level 
                For combinationIndex As Integer = 1 To wordDistance

                    combination.Append(wordsArray(wordIndex + combinationIndex))
                    Next combinationIndex

                'Add this combination to the results 
                returnArray(returnArray.GetUpperBound(0)) = combination.ToString



                'Add a new row to the results, ready for the next combination 
                ReDim Preserve returnArray(returnArray.GetUpperBound(0) + 1)
                
            Next wordIndex

        Next wordDistance

        'Get rid of the last, blank row. 
        ReDim Preserve returnArray(returnArray.GetUpperBound(0) - 1)
    


        'Return combinations to the calling method. 
        Return returnArray

    End Function

End Class

and the alterations to include arraylist

Private Function comboGenerator(ByRef chunk As ArrayList) As ArrayList
            Dim phrase As String = Nothing
            Dim size As Integer = chunk.Count
            Dim myCombinations As String()
            'BuildCombinations(myAnimals)


            For i As Integer = 0 To size - 1
                phrase = phrase & chunk.Item(i)
            Next


            myCombinations = BuildCombinations(phrase)

            For j As Integer = 0 To chunk.Count - 1
                chunk.Add(myCombinations(j))

            Next
            Return chunk
        End Function

I kept the BuildCombinations function the same
Please advise.