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?