一、题目

Given an integer n, return true if it is a power of two. Otherwise, return false.

An integer n is a power of two, if there exists an integer x such that n == 2x.

Example 1:

Input: n = 1
Output: true
Explanation: 20 = 1
Example 2:

Input: n = 16
Output: true
Explanation: 24 = 16
Example 3:

Input: n = 3
Output: false

Constraints:

-231 <= n <= 231 - 1

二、题解

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