How can i use long int in C

Dear Friends,

When i make a program of factorial in C it runs but it doesn't gives the factorial of big numbers. Like 20 or 50. I read about long int data-type in book, but i am unable to process it. Please help in these regards.

 

I think you mean long long not long int. long int is equivalent to long I believe. long long will give you a 64-bit integer value, but even this may not be enough to work with larger factorials.

 

Without a bignum library, you won't be able to do this. C++ just doesn't have the support 'out of the box' for numbers over a certain size. If you're feeling brave, you can code your own. GMP works well, and I'm pretty sure it works with Visual Studio.

http://gmplib.org/

 

Thanks Brian and organicCyborg, I got my answer. Here it is:-

void main()
{
long int a;
printf ("Enter the population of India");
scanf("%ld",&a);

Thanks all for your support.

 

long long int is 64 bits.
long int is long, thus usually 32 bits.
%lld should be fine for printf, but you should really look up the format specifications instead of asking. It's easy.

 

you can have a look at double.

 

I think fot that you should use double variable in it.....instead of long and it is used as int...

 

I think for that you should use double datatype for that variable..