数值的整数次方

 1 class Solution {
 2 public:
 3     double Power(double base, int exponent) {
 4         if (exponent == 0)
 5             return 1;
 6         else if (exponent > 0)
 7         {
 8             
 9             double sum = 1;
10             for (int i = 0 ; i < exponent ;++i)
11                 {
12                     sum = sum*base;
13                 }
14             return sum;
15         }
16         else
17         {
18              exponent = -1 * exponent;
19             double sum = 1;
20             for (int i = 0 ; i < exponent ;++i)
21                 {
22                     sum = sum/base;
23                 }
24             return sum;
25            }
26     }
27 };