题目描述:
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: 2^4 = 16
Example 3:
Input: 218
Output: false
判断一个数是否为2的幂,直接不断除2,判断最后是否为1.
class Solution {
public:
bool isPowerOfTwo(int n) {
while(n>=2)
{
if(n%2==1) return false;
n=n/2;
}
return n==1;
}
};