Power of Two

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:

  • -231 <= n <= 231 - 1

 

Follow up: Could you solve it without loops/recursion?SOLUTION:
class Solution:
    def isPowerOfTwo(self, n: int) -> bool:
        if n <= 0:
            return False
        if n == 1:
            return True
        return not (n & 1) and self.isPowerOfTwo(n >> 1)

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