LeetCode----Power of Two

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.

分析：

简单题，判断一个数是否是2的倍数。我先统计出给定数的二进制中1的个数，如果个数大于1，则为False。

相关学习链接：快速求二进制中1的个数，位运算。

代码：

class Solution(object):
def isPowerOfTwo(self, n):
"""
:type n: int
:rtype: bool
"""
if n <= 0:
return False
count = 0
while n:
n &= n - 1
count += 1
if count == 1:
return True
else:
return False