题目描述

blablabla

样例

class Solution {
public:
    double Power(double base, int exponent) {
        bool mines = false;
        if(exponent<0){
            exponent = exponent*-1;
            mines = true;
        }else if(exponent==0){
            return 1;
        }
        double res = 1;
        int t = base;
        while(exponent){
            if(exponent&1){
                res *=t;
            }
            exponent >>= 1;
            t = t*t;
        }
        if(mines) return 1/res;
        return res;
    }
};