数值的整数次方

题目描述

给定一个double类型的浮点数base和int类型的整数exponent。求base的exponent次方。

class Solution {
public:
    double Power(double base, int exponent) {
        if(exponent == 0)
            return 1;
        
        long long ans = 1;
        int temp = exponent;
        exponent = abs(exponent);
        while(exponent)
        {
            if(exponent&1)
                ans *= base;
            
            exponent = exponent >> 1;
            base = base * base;
        }
        return temp>0?ans:1.0/ans;
    }
};