Thread: Mod question...

How can I calculate it in C?

20X(77^2) mod 119

It's too big... even can't use pow/%/mod.....

thx!!

How is that too big? A modulus can't get that big. Here is the code I used to check it:

Code:

#include <stdio.h>
#include <stdlib.h>
#include <math.h>

int main()
{
   long int number;

   number = (20 * pow(77, 2));
   number = number % 119; 
      
   printf("Answer: %d\n", number);

   system("PAUSE");
   return 0;
}

I think your problem was the face that you didn't use a long int.

Good luck

Originally posted by klausi
Hi!
Did you know that you can even declare a long long int in C?
It works, but I have never used it.

klausi

However... it doesn't work on me with long long int......
anyway... thx!!

Accurate arithmetic on truly large numbers requires the support of a library.

Here's one example
http://swox.com/gmp/

Originally posted by biosx
How is that too big? A modulus can't get that big. Here is the code I used to check it:

Code:

#include <stdio.h>
#include <stdlib.h>
#include <math.h>

int main()
{
   long int number;

   number = (20 * pow(77, 2));
   number = number % 119; 
      
   printf("Answer: %d\n", number);

   system("PAUSE");
   return 0;
}

I think your problem was the face that you didn't use a long int.

Good luck

I mean 20^77....

It shouldn't be number = (pow(20,77));??