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[Solved]Could someone help me fix my is_prime function?


E1M1
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I tried to convert C# conde from wiki to autoit http://en.wikipedia.org/wiki/Trial_division

That's what I got

Func is_prime($number)

if ($number < 2) Then return false;

$d = 2

While ($d * $d <= $number)

$d +=1

if (Mod($number, $d) == 0) Then

return false;

EndIf

WEnd

return true;

EndFunc

This function always returns me true.. for example it returns true for 99, but you can devide 99 with 3, so it's not primenumber. Could someone help me fixing this function pleae?

Edited by E1M1

edited

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E1M1,

I use this function to check primes: :graduated:

For $i = 1 To 100
    If _IsPrime($i) Then ConsoleWrite($i & @CRLF)

Next

Func  _IsPrime($i)

    If $i < 2 Then
        Return False
    ElseIf $i < 4 Then
        Return True
    ElseIf Mod($i, 2) = 0 Then
        Return False
    Else
        $id = 3
        Do
            If Mod($i, $id) = 0 Then Return False
            $id += 2
        Until $id * $id > $i
        Return (($id * $id) > $i)
    EndIf

EndFunc

M23

Edit: See you solved it yourself - would delete post if I could! :(

Edited by Melba23

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IsPrime functions can be horribly slow, and including a (not too long) table of initial primes speeds them up tremendously:

:graduated:

Valuater's AutoIt 1-2-3, Class... Is now in Session!For those who want somebody to write the script for them: RentACoder"Any technology distinguishable from magic is insufficiently advanced." -- Geek's corollary to Clarke's law
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