Power of Four
Difficulty: Easy
Category: DSA
Topics: Math, Bit Manipulation, Recursion
Asked at: Two Sigma
Given an integer `n`, return _`true` if it is a power of four. Otherwise, return `false`_.
An integer `n` is a power of four, if there exists an integer `x` such that `n == 4x`.
**Example 1:**
**Input:** n = 16
**Output:** true
```
**Example 2:**
**Input:** n = 5
**Output:** false
```
**Example 3:**
**Input:** n = 1
**Output:** true
```
**Constraints:**
- `-231 <= n <= 231 - 1`
**Follow up:** Could you solve it without loops/recursion?