[leetcode]231. Power of Two

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

Example 1:

Input: 1
Output: true 
Explanation: 20 = 1

分析：

给定一个整数，判断其是否为2的幂。只要%2求余数不为0，则返回false；否则一直/2，判断最后是否为1，为1则为true

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