LeetCode231 Power of Two 2的冪

1. problem description

Given an integer, write a function to determine if it is a power of two.

Example 1:
Input: 1
Output: true
Explanation: 2^0 = 1

Example 2:
Input: 16
Output: true
Explanation: 24 = 16

Example 3:
Input: 218
Output: false

2. solution

class Solution {
public:
    bool isPowerOfTwo(int n) {
        return n > 0 && !(n&(n-1));
    }
};