题解 | #数值的整数次方#

class Solution {
public:
    double Power(double base, int exponent) {
        if(base==0.0&&exponent<0)
            return 0.0;
        if (exponent==0) 
            return 1;
        if(exponent==1)
            return base;
        if(exponent<0)
        {
            base=1/base;
            exponent=-exponent;
        }
        double result=1.0;
        while (exponent>0) {
            if(exponent&0x1==1)//位运算效率更高
                result*=base;
            base*=base;
            exponent=exponent>>1;//位运算效率更高
        }
        return result;
    }
};