LeetCode – Refresh – Pow(x, n)

 1 class Solution {
 2 public:
 3     double pow(double x, int n) {
 4         bool sign = false;
 5         if (n < 0) {
 6             n = -n;
 7             sign = true;
 8         }
 9         double power = x, result = 1.0;
10         while (n > 0) {
11             if (n%2 == 1) {
12                 result *= power;
13             }
14             power *= power;
15             n /= 2;
16         }
17         if (sign) return 1/result;
18         return result;
19     }
20 };