231. Power of Two

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Problem

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

Example 1:

Input: 1
Output: true
Explanation: 20 = 1

Example 2:

Input: 16
Output: true
Explanation: 24 = 16

Example 3:

Input: 218
Output: false

Code

class Solution:
    def isPowerOfTwo(self, n: int) -> bool:
        if n == 0:
            return False
        while n % 2 == 0:
            n /= 2
        return n == 1

class Solution:
    def isPowerOfTwo(self, n: int) -> bool:
        return n > 0 and (n & (n - 1) == 0)