Leetcode 231. Power of Two

文章作者：Tyan
博客：noahsnail.com  |  CSDN  |  简书

1. Description

Power of Two

2. Solution

• Version 1

class Solution {
public:
    bool isPowerOfTwo(int n) {
        if(n == 0) {
            return false;
        }
        while(n != 1) {
            if(n % 2) {
               return false; 
            }
            n /= 2;
        }
        return true;
    }
};

• Version 2

class Solution {
public:
    bool isPowerOfTwo(int n) {
        if(n == 0) {
            return false;
        }
        while(n != 1) {
            if(n % 2) {
               return false; 
            }
            n >>= 1;
        }
        return true;
    }
};

• Version 3

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

Reference

1. https://leetcode.com/problems/power-of-two/description/