Best way to check if a string contains all of the integers from 1 to N with no duplicates?

[JenniferMurphy]

I am working on a UDF to generate a random set of counting numbers on [1,N]. For example, "3 2 5 4 1".

Now I want to write another UDF to test it. What I have come up with is to split the result string into an array, create another array of the same length, loop through the result array setting a code in the second array. If I find a code already set, the code fails. Here's my code. Is there a better way?

Function TestRandSelect(pM As Long, pN As Long) As Variant

Dim iTally As Long
Dim Result As Variant
Dim ResultArray As Variant
Dim TallyArray() As Variant
Dim NextRand As Long

ReDim TallyArray(1 To pN)

' To be done in a loop
  Result = RandSelect1(pM, pN)
  ResultArray = Split(Result)
  For iTally = 1 To pM
    NextRand = ResultArray(iTally)
    If TallyArray(NextRand) <> "" Then
      TestRandSelect = "Error"
      Exit Function
    End If
    TallyArray(NextRand) = "X"
  Next iTally
  
TestRandSelect = "OK"

End Function

 

[BSALV]

use a dictionary, that's made for that.
But if it's good generated, you don't need the test
Random select N number between 1 and N (exact same, thus normally without duplicates).
If the sum of them is N * (N+1) / 2 then there are no duplicates.

 

[Peter_SSs]

I don't have the RandSelect1 function so I have structured this a different way but you should be able to adapt to your structure.
This requires no looping & no dictionary.

Function Test(Result) As String
  Dim a As Variant, b As Variant
  
  a = Split(Result)
  b = Application.Transpose(Evaluate("row(1:" & UBound(a) + 1 & ")"))
  Test = "Error"
  If Join(b) = Join(WorksheetFunction.Sort(Split(Result), , , True)) Then Test = "OK"
End Function

I tested it by feeding strings directly like this but you could use the strings from your RandSelect1 function/

Sub Test_Function_Test()
  MsgBox Test("3 2 5 4 1")
End Sub

 

[BSALV]

WorksheetFunction.Sort is what ? Since excel-2019 or 2021 ?

 

[Peter_SSs]

WorksheetFunction.Sort is what ? Since excel-2019 or 2021 ?