Project euler no. 3
MRAB
python at mrabarnett.plus.com
Sat Sep 12 18:14:45 CEST 2009
Someone Something wrote:
> But, I'm returning true or false right?
>
No. If you don't explicitly return a value then None will be returned.
> On Sat, Sep 12, 2009 at 11:32 AM, MRAB <python at mrabarnett.plus.com
> <mailto:python at mrabarnett.plus.com>> wrote:
>
> Someone Something wrote:
>
> Project euler (in case you don't know: projecteuler.net
> <http://projecteuler.net> <http://projecteuler.net>)
>
>
> I'm trying to do the third one and here's my current code:
>
> 1 def checkPrime (x):
> 2 factors=2;
> 3 while factors<=x:
> 4 if x==factors:
> 5 return True;
> 6 elif x%factors==0:
> 7 return False;
> 8 elif x%factors!=0:
> 9 factors=factors+1;
>
>
> You're not returning 'factors', so the function will return None.
>
>
> 10
> 11 factorl=[];
> 12 factors=600851475142;
> 13
> 14 while factors != 1:
> 15 if 600851475143%factors==0:
> 16 if checkPrime(factors)==True:
> 17 print factors;
> 18 else:
> 19 factors=factors-1;
> 20
> 21 else:
> 22 factors=factors-1;
> 23
>
> And it just gets frozen when I run it. I put a
>
> print "Loop completed"
>
> in one of the loops and it showed up just fine. So, there are
> two possibilities:
> 1. Its looping in the trillions and taking a while
> 2. I have a forever loop somewhere
>
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