leetcode之Power of Two

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

Credits:

Special thanks to @jianchao.li.fighter for adding this problem and creating all test cases.

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该题判断一个数是否为2的幂，这里利用的是二进制的方法，如果一个数为2的幂，则只有首位为1，所以与其减一的结果相与的结果为0。

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