leetcode:231. Power of Two

Given an integer, write a function to determine if it is a power of two.
大概意思就是給一個整數n，判斷這個數是不是2的幾次方最後得到的值（忘了叫什麼了，冪還是？額大概就是這個意思。）
2^0=1
記得小時候劃過這個函數圖最小值就是1
所以要有一個判斷的條件就是n<=1時，就一定不符合條件返回False

class Solution(object):
    def isPowerOfTwo(self, n):
        """
        :type n: int
        :rtype: bool
        """
        if n <= 0:
            return False

        count = 0

        for x in range(0,32):
            if (n & 1) == 1:
                count = count + 1
            n = n >> 1

        return count == 1

參考鏈接

https://www.youtube.com/watch?v=jLY1Zrj9AZ0&list=PLAE-zml3hxQvdC8iD61W9-lqeUd4RWC45