位运算（5）——Power of Two

 1 public class Solution {
 2     public boolean isPowerOfTwo(int n) {
 3         int count = 0;
 4         if (n <= 0) {
 5             return false;
 6         } else {
 7             while (n != 0) {
 8                 if ((n & 1) == 1) {
 9                     count++;
10                 }
11                 n = n >> 1;
12                 if (count > 1) {
13                     return false;
14                 }
15             }
16             return true;
17         }
18     }
19 }