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;    }};