Raising large number to large power and mod it by a large number?

Question

I am stuck with probably simple question. I got 3 large numbers(A,B,C), all integers and i need to do the following: power A to B and modulo the result by C, and then check if t

Answer 1

The min and max sizes for Double are -1.7*10^308 and 1.7*10^308 respectively. If you need bigger you could try long long.

Not sure why you are using fmod. But this should do what you want.

double power = ( pow(A, B) ) % C;
if (power != 1){
        printf("Something!\n");
    }