C = 10
'mutaterate has to be greater than 1 or it will not mutate
mutaterate = 2
mutationstaken = 0
generations = 0
Dim parentcopies$((C - 1))
Global targetString$ : targetString$ = "METHINKS IT IS LIKE A WEASEL"
Global allowableCharacters$ : allowableCharacters$ = " ABCDEFGHIJKLMNOPQRSTUVWXYZ"
currentminFitness = Len(targetString$)

For i = 1 To Len(targetString$)
    parent$ = parent$ + Mid$(allowableCharacters$, Int(Rnd(1) + 1 * Len(allowableCharacters$)), 1)  'corrected line
Next i

Print "Parent = " + parent$

While parent$ <> targetString$
    generations = (generations + 1)
    For i = 0 To (C - 1)
        parentcopies$(i) = mutate$(parent$, mutaterate)
        mutationstaken = (mutationstaken + 1)
    Next i
    For i = 0 To (C - 1)
        currentFitness = Fitness(targetString$, parentcopies$(i))
        If currentFitness = 0 Then
            parent$ = parentcopies$(i)
            Exit For
        Else
            If currentFitness < currentminFitness Then
                currentminFitness = currentFitness
                parent$ = parentcopies$(i)
            End If
        End If
    Next i
    CLS
    Print "Generation - " + str$(generations)
    Print "Parent - " + parent$
    Scan
Wend

Print
Print "Congratulations to me; I finished!"
Print "Final Mutation: " + parent$
'The ((i + 1) - (C)) reduces the total number of mutations that it took by one generation
'minus the perfect child mutation since any after that would not have been required.
Print "Total Mutations Taken - " + str$(mutationstaken - ((i + 1) - (C)))
Print "Total Generations Taken - " + str$(generations)
Print "Child Number " + str$(i) + " has perfect similarities to your target."
End



Function mutate$(mutate$, mutaterate)
        If (Rnd(1) * mutaterate) > 1 Then
            'The mutatingcharater randomizer needs 1 more than the length of the string
            'otherwise it will likely take forever to get exactly that as a random number
            mutatingcharacter = Int(Rnd(1) * (Len(targetString$) + 1))
            mutate$ = Left$(mutate$, (mutatingcharacter - 1))  + Mid$(allowableCharacters$, Int(Rnd(1) * Len(allowableCharacters$)), 1) _
                      + Mid$(mutate$, (mutatingcharacter + 1))
        End If
End Function

Function Fitness(parent$, offspring$)
    For i = 1 To Len(targetString$)
        If Mid$(parent$, i, 1) <> Mid$(offspring$, i, 1) Then
            Fitness = (Fitness + 1)
        End If
    Next i
End Function