题解 | #数值的整数次方#

/**
 * @author jingbu

 *
 *  数值的整数次方
 *      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。
 */
public class Main {
    public static void main(String[] args) {

    }
}

class Solution {
    public double Power(double base, int exponent) {

        //如果exponent小于0，用1除以正数的值
        return exponent<0?1/dfs(base,-exponent):dfs(base,exponent);
    }

    //一直递归到exponent为0
    public double dfs(double base, int exponent){
        if(exponent==0){
            return 1;
        }
        double y=dfs(base,exponent/2);
        return exponent%2==0?y*y:y*y*base;
    }
}