More than 4,294,967,296 in C?

Question

Possible Duplicate:
“BigInt” in C?

Hey there! I'm calculating the Fibonacci numbers in C up to 46 using an unsigned int, but I can't calculate F(47) because it's long. So, is there a way to get numbers bigger than 2^32 in C?
NB: I use a 32-bit processor.

score 11 · Accepted Answer · answered Aug 08 '10 at 13:51

11

(unsigned) long long, but it's also limited (to 2^64). If it's not enough, you need to look for a BigInt library.

answered Aug 08 '10 at 13:51

GameZelda

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Of course, on x86 and some other architectures, you can push it to 128 bits with a `__uint128_t`... – haneefmubarak May 11 '14 at 18:59

score 2 · Answer 2 · answered Aug 08 '10 at 13:59

2

#include <stdint.h>

uint64_t my64bit;

answered Aug 08 '10 at 13:59

Dacav

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score 1 · Answer 3 · answered Aug 08 '10 at 14:02

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You could try using 64-bit unsigned integers (check your C implementation for support), or simply use a BigNum package like GMP.

In the past, I've made BigNum libraries myself for various purposes but GMP blows my meagre efforts out of the water.

answered Aug 08 '10 at 14:02

paxdiablo

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score 1 · Answer 4 · edited May 23 '17 at 10:33

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I love the answer given by user R.. for this question here to operate on bigints. Of-course you have to implement your own add function if you want to scale it to very large numbers. It explains the steps very clearly.

edited May 23 '17 at 10:33

Community

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answered Aug 08 '10 at 14:21

Praveen S

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score 0 · Answer 5 · answered Aug 08 '10 at 13:53

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You should implement your own data type that is able to hold big numbers or use a library such as this one.

answered Aug 08 '10 at 13:53

Hamid Nazari

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More than 4,294,967,296 in C?

5 Answers5