Pow(x, n)

Implement pow(x, n).

class Solution {
public:
    double pow(double x, int n) {
        double result = 1;
        double factor = x;
        bool negative = false;
        if (n < 0)
        {
            n *= -1;
            negative = true;
        }

        while (n > 0)
        {
            if (n & 1)
            {
                result *= factor;
            }
            factor *= factor;
            n >>= 1;
        }

        if (negative)
        {
            result = 1/result;
        }

        return result;
    }
};