How to create an integer data type with over 1 billion digits in c

I'm working on a prodgect in which I need a huge number, 1 billion dig开发者_如何学运维its. I'm writing in c, though I'll take answers from objective-c.

Also, I'm wondering about this function/data type I found: Biginteger.

I would like to know what language people use this in and if it will help my problem.

Please respond, Frederick

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There is the GMP bignum library, if that's what you are asking.
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