text: """
  
  link: https://leetcode.com/problems/power-of-two
  
  problem: 判断数字是否是2的幂
  
  solution: 去除首位1后判断是否为0
  
  """
  class Solution:
      def isPowerOfTwo(self, n: int) -> bool:
          if n == 0:
              return False
          return n & (n - 1) == 0