"""
Given an integer n, return true if it is a power of two. Otherwise, return false.
An integer n is a power of two, if there exists an integer x such that n == 2x.

Example 1:
Input: n = 1
Output: true
Explanation: 20 = 1

Example 2:
Input: n = 16
Output: true
Explanation: 24 = 16

Example 3:
Input: n = 3
Output: false

Constraints:
-2^31 <= n <= 2^31 - 1

Follow up: Could you solve it without loops/recursion?
"""

class PowerOfTwo:
    def isPowerOfTwo(self, n: int) -> bool:
        return n and not (n & n - 1)