<p>Given an integer <code>n</code>, return <em><code>true</code> if it is a power of three. Otherwise, return <code>false</code></em>.</p> <p>An integer <code>n</code> is a power of three, if there exists an integer <code>x</code> such that <code>n == 3<sup>x</sup></code>.</p> <p> </p> <p><strong>Example 1:</strong></p> <pre> <strong>Input:</strong> n = 27 <strong>Output:</strong> true </pre> <p><strong>Example 2:</strong></p> <pre> <strong>Input:</strong> n = 0 <strong>Output:</strong> false </pre> <p><strong>Example 3:</strong></p> <pre> <strong>Input:</strong> n = 9 <strong>Output:</strong> true </pre> <p> </p> <p><strong>Constraints:</strong></p> <ul> <li><code>-2<sup>31</sup> <= n <= 2<sup>31</sup> - 1</code></li> </ul> <p> </p> <strong>Follow up:</strong> Could you solve it without loops/recursion?