Leetcode: Pow(x, n)

Recursive solution is easier to understand. It uses the divide-and-conquer approach, which also runs in  time. The formula is shown below:

And the code is quite simple and straightforward.

code:

 1 class Solution {
 2 public:
 3     double pow(double x, int n) {
 4         // Start typing your C/C++ solution below
 5         // DO NOT write int main() function
 6         if (n == 0)
 7             return 1.0;
 8         double half = pow(x, n/2);
 9         if (n % 2 == 0)
10             return half * half;
11         else if(n > 0)
12             return half * half * x;
13         else 
14             return half * half / x;
15     }
16 };

 

posted @ 2013-05-02 14:29  caijinlong  阅读(130)  评论(0)  编辑  收藏  举报