[RESOLVED] Loop is slowing down greatly.

[Troy Lundin]

I have a loop in my program that iterates at the start about 20,000 - 25,000 times per second. By the end of the loop, the iteration is down to about 6000 per second.

Here is my code.

    Sub FindAnagrams(ByVal s As String)
        ' Remove the string we are currently using from the queue
        If Not AnagramQueue.Count = 0 Then AnagramQueue.RemoveAt(0)

        ' Loop through each character in the string
        For n As Integer = 0 To s.Length - 1

            ' Since all Anagrams of a particular word have the same exact letters,
            ' alphabetizing them will help us weed out the duplicates.
            AlphaString = Alphabetize(s)

            ' This loop lops of the nth letter and adds the rest of the string to our lists.
            While AlphaString.Length > 0
                NumPathsSearched += 1
                ' If the anagram hasn't been found yet, add it.
                If Not FoundAnagrams.Contains(AlphaString) Then
                    AnagramQueue.Add(AlphaString)
                    FoundAnagrams.Add(AlphaString)
                    UpdateAnagramUI()
                End If

                ' Prevent an OutOfRange exception
                If n >= AlphaString.Length Then
                    Exit While
                Else
                    AlphaString = AlphaString.Remove(n, 1)
                End If
            End While

            ' Recurse
            While AnagramQueue.Count > 0
                   FindAnagrams(AnagramQueue(0))
            End While

        Next
    End Sub

AnagramQueue and FoundAnagrams are List(Of String).
The Alphabetize function merely returns the string with it's Chars in abc order.

Can you see any bottlenecks or any reasons for the slowdown?