How to deal with large numbers which cannot be store by int in c

Question

I am trying to do modulus operator on number upto 10^18. i cannot store this numbers in int and if i take it float then i cannot apply modulus operator so how can i do it.

I searched it but didn't find my answer.

I found one method to typecast but it cannot solve my problem and other is to use array.

So , there is only way to use array.

You don't show the calculation, but it can be posssible to do the modulus on its steps, so it never gets large. — Weather Vane, Feb 11 '16 at 19:59
If you're using the C99 standard or later, you can use the [long long](https://en.wikipedia.org/wiki/C_data_types#Basic_types) type, which is at least 64 bits, and will hold 10^18. — skrrgwasme, Feb 11 '16 at 20:00
Possible duplicate of [Declaring 64-bit variables in C](http://stackoverflow.com/questions/19451101/declaring-64-bit-variables-in-c) — user3386109, Feb 11 '16 at 20:02
Here is a list from wikipedia: https://en.wikipedia.org/wiki/List_of_C%2B%2B_multiple_precision_arithmetic_libraries but it doesn't include all of them - there are a bunch more. See: https://www.google.co.nz/search?q=c%2B%2B+arbitrary+precision — Jerry Jeremiah, Feb 11 '16 at 20:17
You have kind of modulus operations on floating point see for example http://linux.die.net/man/3/remainder - it's just that 10^18 takes about 60 bits of data, a bit too much for IEEE double precision — aka.nice, Feb 11 '16 at 21:08

score 3 · Answer 1 · edited Feb 11 '16 at 20:15

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Use a long long int which ranges from −9,223,372,036,854,775,808 to +9,223,372,036,854,775,807. For unsigned values you can use unsigned long long int, which ranges from 0 to 18,446,744,073,709,551,615

Here are your choices

long long
long long int
signed long long
signed long long int
unsigned long long
unsigned long long int

edited Feb 11 '16 at 20:15

user3386109

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answered Feb 11 '16 at 20:04

Jonh Doe

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yeah it's more like it depends on the platform, and the edited version by user3386109 is correct. – Jonh Doe Feb 11 '16 at 20:15
the int is optional so long long is equal to long long int, but I suggest using long long int it's clearer for non C or new C programmers. – Jonh Doe Feb 11 '16 at 20:27

score 0 · Answer 2 · answered Feb 11 '16 at 20:05

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For long number you can use unsigned long long int or long long int If this not working for you than you can use filing for storing values.

answered Feb 11 '16 at 20:05

Faraz Sultan

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"Use filing for storing values"? – user253751 Feb 11 '16 at 20:36

How to deal with large numbers which cannot be store by int in c

2 Answers2