Pow(x, n)

Implement pow(x, n).

Example 1:

Input: 2.00000, 10
Output: 1024.00000

Example 2:

Input: 2.10000, 3
Output: 9.26100

public double myPow(double x, int n) {
        if (n<0) return 1/Pow(x,-n);
        return Pow(x,n);
    }
    double Pow(double x,int n){
        if (n==0) return 1;
        double half = Pow(x,n/2);
        if ((n&1)==0){
            return half*half;
        }
        return x*half*half;
    }