Author 
Message 
Chocoholic
Joined: 16 Feb 2009 Posts: 44 Location: UK 



abc: I don't quite get what you want to say.
Anyways, you might want to notice that the text reads "the 1500000th member" of the sequence, not F(1500000). There's a difference, and I calculated 3 different numbers until I got the right one.


Sat Feb 21, 2009 12:15 am 


quwieorp
Joined: 07 Apr 2009 Posts: 2




So how is the Fibonacci sequence defined in this challenge?
Like this?:
Fib(0) = 0
Fib(1) = 1
Fib(2) = 1
Fib(3) = 2
Fib(1 500 000) <


Thu Apr 09, 2009 12:34 pm 


lukas
Joined: 26 Nov 2008 Posts: 34 Location: Germany 



If he is right:


It starts with 129... and ends with ...000 
Then you have to take the "1500001" if you count like that:
"Fib(0) = 0
Fib(1) = 1
Fib(2) = 1
Fib(3) = 2"
I have this number, but still don't get the answer. Something on my every 20.000 function must be wrong


Thu Apr 09, 2009 1:52 pm 


tschiew
Joined: 05 Mar 2009 Posts: 11






So how is the Fibonacci sequence defined in this challenge?
Like this?:
Fib(0) = 0
Fib(1) = 1
Fib(2) = 1
Fib(3) = 2
Fib(1 500 000) 
No, the sequence is defined as follows:
Fib(0) = 0
Fib(1) = 1
Fib(2) = 2
...
I also got this problems....


Tue Apr 14, 2009 5:27 pm 


cutter
Joined: 12 Jan 2009 Posts: 17




looks like the sequence of the natural numbers


Tue Apr 14, 2009 5:49 pm 


wiz1989
Joined: 19 Feb 2009 Posts: 10 Location: Germany 



It's
Fib(0) = 1
Fib(1) = 1
Fib(2) = 2
Fib(3) = 3
Just to be correct


Tue Apr 14, 2009 8:49 pm 


teebee
Joined: 10 Nov 2008 Posts: 89 Location: Germany 



looks like the sequence of the natural numbers with one exception


Tue Apr 14, 2009 9:01 pm 


blablaSTX
Joined: 17 Aug 2009 Posts: 11




there is no need for it be prime, so please do not discard your result simply because it ends in zeros.


(1 to:20) collect:[:n  n fib]

gives:
#(1 1 2 3 5 8 13 21 34 55 89 144 233 377 610 987 1597 2584 4181 6765)
of which 8, 21, 34, 55 ... are NOT prime.
And, as you can see, "fib 15" also gives you a number which ends in a zero.


Tue Aug 25, 2009 1:03 pm 


quangntenemy
Joined: 02 Jul 2009 Posts: 8




Do you guys calculate it the traditional way? It's kinda slow for me.


Sun Aug 30, 2009 5:08 am 


blablaSTX
Joined: 17 Aug 2009 Posts: 11




... "in the traditional way" ...
Almost; two little tricks help with big numbers, though (both a math trick and a coding trick).
That should not reveal too much info, I hope.


Mon Aug 31, 2009 6:23 pm 


whattheh@ck
Joined: 16 Jul 2008 Posts: 16 Location: here 



I was able to do it in about 10 minutes using Python... It's very good at handling large integers. The answer is 16 digits long so the actual number has to be over 320,000 digits long.
_________________ hack the planet 

Sun Nov 08, 2009 1:24 am 


CodeX
Joined: 17 Oct 2008 Posts: 350



Sun Nov 08, 2009 1:43 pm 


Guderian
Joined: 25 Jan 2011 Posts: 18 Location: Greece 



i solved with the recursive way and c++. I used to huge char arrays of 1 million bytes each to store the results. It took 5 hours to get the result. However the tricky part is the next challenge, must find a way to calculate the ln of this array


Sun Jan 30, 2011 1:55 pm 


Millennium
Joined: 21 Apr 2011 Posts: 17


A Word to the Wise 

It's not the 1st digit, followed by the 20,000th digit, etc. or the 20,000th followed by the 40,000th, but rather the 1st followed by the 20,001st. That's what originally got me XD


Sun May 15, 2011 7:07 pm 


compudemon
Joined: 13 Aug 2011 Posts: 33




lucky for me i got it on the first try, it does not help that the web does not agree weather it is
1,1,2,3,5
0,1,1,2,3,5
or if the first in the sequence would be 0 or 1
so here is a hint
55 is the 10th number in the fib series given by the same code i solved it with
i used python i would say it was solved in less then 5 mins, i left when it wasn't an instant answer


Thu Aug 18, 2011 7:11 pm 


