]数值的整数次方

 1 public class Solution {
 2     public double Power(double base, int exponent) {
 3         if(exponent==1) return base;
 4         if(exponent==-1) return 1/base;
 5         if(exponent==0) return 1; 
 6         double res = Power(base, exponent>>1);
 7         res = (exponent & 0x1)==1?  base *res*res:res*res;
 8         return res; 
 9   }
10 }