What is the most efficient way to calculate the least common multiple of two integers?

Question

What is the most efficient way to calculate the least common multiple of two integers?

I just came up with this, but it definitely leaves something to be desired.

Answer 1

Euclidean GCD code snippet

int findGCD(int a, int b) {
        if(a < 0 || b < 0)
            return -1;

        if (a == 0)
            return b;
        else if (b == 0)
            return a;
        else 
            return findGCD(b, a % b);
    }