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?