Handling large integers in c++

Question

How can i handle very large integers like 2^100000000 in c++?

I found no solution for this on internet that gives an exact answer.

Is there any mechanism that gives correct value in c++ for such large integers?

Have you searched on stackoverflow? There must be at least one answer suggesting e.g. gmp. There's no _standard_ way (yet), but there are a ton of ways. Look closer. — stefan, Nov 02 '13 at 20:52
Try searching for [BigNum](http://en.wikipedia.org/wiki/Arbitrary-precision_arithmetic). — crashmstr, Nov 02 '13 at 20:53
It's a bit out of the standard range to call it "integer" -- your number has 3 *million* digits. Maybe that's why your search turned up nothing. — Jongware, Nov 02 '13 at 20:56
i searched on stackoverflow and about bignum ... but very long process than my program :( — hanugm, Nov 02 '13 at 20:56
What do you mean by 'handle'? Do you just want to get the decimal representation of such a number or do you want to do calculations with it? — mattnewport, Nov 02 '13 at 21:01

score 4 · Answer 1 · answered Nov 03 '13 at 07:41

4

What you are looking for is called arbitrary precision arithmetic, you will find numerous libraries and educational resources with some googling.

answered Nov 03 '13 at 07:41

Raff.Edward

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score 0 · Answer 2 · edited Nov 02 '13 at 21:27

0

You can represent given number as a string and convert it to array with integer digits. But the simplest way to google by keywords "long arithmetic c++ library" or something.

edited Nov 02 '13 at 21:27

indiv

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answered Nov 02 '13 at 21:11

mikhdm

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score 0 · Answer 3 · answered Nov 03 '13 at 07:52

Maybe you want to use a Computer Algebra System (CAS), which would represent your expression like this:

class Pow : public Expr {
  Number base;
  Number exp;
};

Pow expr = new Pow(2, 100*1000*1000);

A CAS then allows you to manipulate these expressions structurally instead of the concrete values.

Handling large integers in c++

3 Answers3