using big integer values in cpp

Question

how can we use big integer values in cpp? is there any library ?
i have already tried long long unsigned int and the requirement of my program is even more than this.

Answer 1

Saurabh Tiwari The easy way would be to use a string and simply apply addition and subtraction like you learned in school.
You know add 2 digits and keep track of any carries.

The more efficient, longer and less trivial solution would be to an array and store each number in base 2^64-1.

I recommend that you download the library and read through its source code and learn from it, which does exactly that.

Answer 2

Default
Sahil Bhakat
thanks guys
but i have to use modulo (%) operator and double doesnt allow it

Answer 3

I know it isn't an integer, but... how about long double?

This is 128-bits (2^128 MAX), opposed to unsigned long long int's (2^64 MAX).

Answer 4

Dennis can you explain how to do that.
Thnx😊

Answer 5

How big does the number have to be?

Answer 6

Here is a big integer library: https://mattmccutchen.net/bigint/

It's pretty old though, but still good.

Answer 7

Saurabh Tiwari No it's not, you could implement a simple big int class yourself though. :)

Sadly using long double isn't accurate anymore after 2^64-1.

Answer 8

Yeah Default is right you can use long double it has a range from -1.7×10^(4932) upto 1.7×10^(4932).

Answer 9

Default 10^200

Answer 10

Or you you have to put variable somewhere where double will give give you a error

Answer 11

Do you have to use it in a comparison statement or something? ?

Answer 12

Dennis but it is not supported in SL's compiler