by Kevin Lawrence (1 Submission)
Category: Math/Dates
Compatability: Visual Basic 3.0
Difficulty: Unknown Difficulty
Date Added: Wed 3rd February 2021
Rating: 
(9 Votes)
With this simple, and very fast, routine you can generate a series of non-repeating random numbers. You can select a series of 10 numbers, or a series of a million...It doesn't matter. Can be useful for image fades, deck shuffling, random tip of the day, etc. - It even tells you how long it took to generate the series.
Code Returns
A popup message stating how many numbers had been mixed up and how long it took.
Side Effects
The larger the series of numbers the more RAM required. Uses arrays.
API Declarations
VBcodersPrivate Sub Command1_Click()
'-------------------------------------------------------------
' Produces a series of X random numbers without repeating any
'-------------------------------------------------------------
'Results can be used by using array B(X)
Dim A(10000) ' Sets the maximum number to pick
Dim B(10000) ' Will be the list of new numbers (same as DIM above)
Dim Message, Message_Style, Message_Title, Response
'Set the original array
MaxNumber = 10000 ' Must equal the DIM above
For seq = 0 To MaxNumber
A(seq) = seq
Next seq
'Main Loop (mix em all up)
StartTime = Timer
Randomize (Timer)
For MainLoop = MaxNumber To 0 Step -1
ChosenNumber = Int(MainLoop * Rnd)
B(MaxNumber - MainLoop) = A(ChosenNumber)
A(ChosenNumber) = A(MainLoop)
Next MainLoop
EndTime = Timer
TotalTime = EndTime - StartTime
Message = "The sequence of " + Format(MaxNumber, "#,###,###,###") + " numbers has been" + Chr$(10)
Message = Message + "mixed up in a total of " + Format(TotalTime, "##.######") + " seconds!"
Message_Style = vbInformationOnly + vbInformation + vbDefaultButton2
Message_Title = "Sequence Generated"
Response = MsgBox(Message, Message_Style, Message_Title)
End Sub
