Greatest GCD between some numbers

Question

We've got some nonnegative numbers. We want to find the pair with maximum gcd. actually this maximum is more important than the pair! For example if we have:

2 4 5 15

gcd(2,4)=2

gcd(2,5)=1

gcd(2,15)=1

gcd(4,5)=1

gcd(4,15)=1

gcd(5,15)=5

The answer is 5.

Answer 1

You can use the Euclidean Algorithm to find the GCD of two numbers.

while (b != 0) 
{
    int m = a % b;
    a = b;
    b = m;
}
return a;