Given an integer, write a function to determine if it is a power of two.
Example 1:
Input: 1 Output: true Explanation: 20 = 1
Example 2:
Input: 16 Output: true Explanation: 24 = 16
Example 3:
Input: 218 Output: false
class Solution { public boolean isPowerOfTwo(int n) { return n > 0 && (n & (n - 1)) == 0; } }
原文：https://www.cnblogs.com/xuanlu/p/11855615.html