Fibonacci numbers

[dleecurt]

Hello, I have a small problem, I am trying to write a program that
will calculate the Fibonacci number series, and I have the code
complete with one problem. I used a long in to store the numbers, and
when the numbers get too large it maxes out the int and I can't count
any higher. I am trying to use extremely large numbers, I would like
to use up to 10^50 or so. So my question is how do I do this? I'm just
learning the language and I can't think of any way around variable
storage limitations. I would appreciate any advice.
Lee ;-)

[Joost Ronkes Agerbeek]

You will have to write your own class for that and overload the arithmic
operators, especially the + in your case.

Of course there is the question of how to store the number. One way to do
it, is to store it as a string. It might not be the most efficient way in
terms of memory and speed, but it does make the implementation
straight-forward. Initialization is also clean, just write:
Huge("123456789 ");

Another way to do it is to use multiple ints (or longs) to store the number.
You could probably implement this more efficiently than with strings, but I
think it makes the code a bit more complicated.

hth,
Joost

[Ryan Winter]

dl******@cc.usu .edu wrote:

Hello, I have a small problem, I am trying to write a program that
will calculate the Fibonacci number series, and I have the code
complete with one problem. I used a long in to store the numbers, and
when the numbers get too large it maxes out the int and I can't count
any higher. I am trying to use extremely large numbers, I would like
to use up to 10^50 or so. So my question is how do I do this? I'm just
learning the language and I can't think of any way around variable
storage limitations. I would appreciate any advice.
Lee ;-)

use a double is probably the easiest as you get 52 bits of accuracy.
Otherwise maybe an __in64.

Ryan

[Ryan Winter]

Ryan Winter wrote:

use a double is probably the easiest as you get 52 bits of accuracy.
Otherwise maybe an __in64.

__int64 :)

[Sam Holden]

On Fri, 10 Oct 2003 15:20:27 +0800,
Ryan Winter <wi*********@op tusnet.com.au> wrote:

dl******@cc.usu .edu wrote:

Hello, I have a small problem, I am trying to write a program that
will calculate the Fibonacci number series, and I have the code
complete with one problem. I used a long in to store the numbers, and
when the numbers get too large it maxes out the int and I can't count
any higher. I am trying to use extremely large numbers, I would like
to use up to 10^50 or so. So my question is how do I do this? I'm just
learning the language and I can't think of any way around variable
storage limitations. I would appreciate any advice.
Lee ;-)

use a double is probably the easiest as you get 52 bits of accuracy.
Otherwise maybe an __in64.

Those won't be useful since 167 bits are needed for 10^50.

A reasonably simple cless could be written to represent such a number,
or an existing implementation of arbitrary precision numbers.

--
Sam Holden

[Karl Heinz Buchegger]

dl******@cc.usu .edu wrote:

Hello, I have a small problem, I am trying to write a program that
will calculate the Fibonacci number series, and I have the code
complete with one problem. I used a long in to store the numbers, and
when the numbers get too large it maxes out the int and I can't count
any higher. I am trying to use extremely large numbers, I would like
to use up to 10^50 or so. So my question is how do I do this? I'm just
learning the language and I can't think of any way around variable
storage limitations. I would appreciate any advice.
Lee ;-)

Search the web for some big number library.
Eg.

http://www.google.com

Search text: "BigNum C++"
--
Karl Heinz Buchegger
kb******@gascad .at

[Chris Theis]

"Sam Holden" <sh*****@flexal .cs.usyd.edu.au > wrote in message
news:slrnbocpm4 .c0l.sh*****@fl exal.cs.usyd.ed u.au...

On Fri, 10 Oct 2003 15:20:27 +0800,
Ryan Winter <wi*********@op tusnet.com.au> wrote:

dl******@cc.usu .edu wrote:

Hello, I have a small problem, I am trying to write a program that
will calculate the Fibonacci number series, and I have the code
complete with one problem. I used a long in to store the numbers, and
when the numbers get too large it maxes out the int and I can't count
any higher. I am trying to use extremely large numbers, I would like
to use up to 10^50 or so. So my question is how do I do this? I'm just
learning the language and I can't think of any way around variable
storage limitations. I would appreciate any advice.
Lee ;-)

use a double is probably the easiest as you get 52 bits of accuracy.
Otherwise maybe an __in64.

Those won't be useful since 167 bits are needed for 10^50.

A reasonably simple cless could be written to represent such a number,
or an existing implementation of arbitrary precision numbers.

A very common way to solve this problem is either splitting or representing
the numbers as a string. For a simple example how you could do this take a
look at http://www.codeproject.com/cpp/largenumber.asp

HTH
Chris

[Ivan Vecerina]

"Joost Ronkes Agerbeek" <jo***@ronkes.n l> wrote in message
news:3f******** *************** @news.xs4all.nl ...
| You will have to write your own class for that and overload the arithmic
| operators, especially the + in your case.
|
| Of course there is the question of how to store the number. One way to do
| it, is to store it as a string. It might not be the most efficient way in
| terms of memory and speed, but it does make the implementation
| straight-forward. Initialization is also clean, just write:
| Huge("123456789 ");
|
| Another way to do it is to use multiple ints (or longs) to store the
number.
| You could probably implement this more efficiently than with strings, but
I
| think it makes the code a bit more complicated.

Not necessarily more complicated.
Instead of using characters to represent decimal digits, you can use
short integers that store a base 10000 digit (0 to 9999).
(this keeps the product of two such digits in range for 'long').
It is easier than dealing with characters, as you don't need to offset
the values by '0' everywhere. Printing the number is also simple enough.

Also, for many computations, it is easier to manipulate the numbers in
little-endian format (units to the left/lower adresses), rather than
the way that we write numbers in strings (units at the end).

std::vector<int > is an option to store such a number...
Regards,
--
http://ivan.vecerina.com

[Alex Vinokur]

"Sam Holden" <sh*****@flexal .cs.usyd.edu.au > wrote in message news:slrnbocpm4 .c0l.sh*****@fl exal.cs.usyd.ed u.au...

On Fri, 10 Oct 2003 15:20:27 +0800,
Ryan Winter <wi*********@op tusnet.com.au> wrote:

dl******@cc.usu .edu wrote:

Hello, I have a small problem, I am trying to write a program that
will calculate the Fibonacci number series, and I have the code
complete with one problem. I used a long in to store the numbers, and
when the numbers get too large it maxes out the int and I can't count
any higher. I am trying to use extremely large numbers, I would like
to use up to 10^50 or so. So my question is how do I do this? I'm just
learning the language and I can't think of any way around variable
storage limitations. I would appreciate any advice.
Lee ;-)

use a double is probably the easiest as you get 52 bits of accuracy.
Otherwise maybe an __in64.

Those won't be useful since 167 bits are needed for 10^50.

A reasonably simple cless could be written to represent such a number,
or an existing implementation of arbitrary precision numbers.

--
Sam Holden

Computing Very Long Fibonacci Numbers (for instance Fibonacci[5,000,000]) :
http://alexvn.freeservers.com/s1/fibonacci.html
=============== =============== =======
Alex Vinokur
mailto:al****@c onnect.to
http://mathforum.org/library/view/10978.html
=============== =============== =======

[dleecurt]

Here is the code that I wrote, It is quite simple. Dose anyone have
and advice on fixing it.I am compiling it under Linux with gcc.
#include<iostre am.h>

int main(void)
{
long fib1 = 1;
long fib2 = 1;
long fib3;
long fib4;

while (fib4 < 400000000)
{
fib3 = fib1 + fib2;
fib4 = fib3 + fib2;
fib1 = fib3;
fib2 = fib4;

cout << fib3 << endl;
cout << fib4 << endl;
}
return 0;
}

I would appriciate any advice or examples on how make the code do what
I want.
Lee