Problem - Power Function

Implement a function that computes $x^n$, where $x$ is a floating-point number and $n$ is an integer (possibly negative).

For example, $pow(2.0, 10) = 1024.0$ and $pow(2.0, -2) = 0.25$.

Before reading on, think: how would you do this? A loop that multiplies $n$ times? That's one way. But can you do better?