Pow(x, n)

Implement pow(x, n).

Solution:

public class Solution {
    public double myPow(double x, int n) {
        if(n==0) return 1;
        double res = myPow(x, n/2);
        return n%2==0 ? res*res : n<0 ? res*res*(1/x) : res*res*x;
    }
}