Thread: Long double does not make sense.

Hello Community,

I wrote a small piece of code to print a fairly large number. Something along the lines of 30!++.
The problem is that what I get instead is a group of random numbers with no meaning, seemingly.
Am I using the notation wrong here?

Code:

#include<stdio.h>
int main(void){
    int i,lim;
    long double k;
    k=1;
    scanf("%d",&lim);
    for(i=1;i<lim;i++){
                      k*=i;
                      printf("%Ld\n",k);
                      }
    system("pause");
}

You need %Lf for long double.

30! would require 108 bits. That's more than long long.
Is long double (128-bit quadruple precision) supported?
"Not all compilers support the quad-precision type. Microsoft Visual C++, for example, makes the long double type synonymous with the double-precision type."

If your compiler does have it, that has a 112 bit mantissa which is sufficient for exact representation of such a large number.

What are the corresponding formatter codes for printf? I have no idea.

If your number is the factorial of 30, you probably want a long int rather than a long double anyway.

As I said, 30! exceeds long long. Best you can do there is 12!

Originally Posted by TheBigH

If your number is the factorial of 30, you probably want a long int rather than a long double anyway.

A float at the very least; a long int ain't gonna cut it.