<p>Given an input string <code>s</code> and a pattern <code>p</code>, implement regular expression matching with support for <code>'.'</code> and <code>'*'</code> where:</p> <ul> <li><code>'.'</code> Matches any single character.</li> <li><code>'*'</code> Matches zero or more of the preceding element.</li> </ul> <p>The matching should cover the <strong>entire</strong> input string (not partial).</p> <p> </p> <p><strong>Example 1:</strong></p> <pre> <strong>Input:</strong> s = "aa", p = "a" <strong>Output:</strong> false <strong>Explanation:</strong> "a" does not match the entire string "aa". </pre> <p><strong>Example 2:</strong></p> <pre> <strong>Input:</strong> s = "aa", p = "a*" <strong>Output:</strong> true <strong>Explanation:</strong> '*' means zero or more of the preceding element, 'a'. Therefore, by repeating 'a' once, it becomes "aa". </pre> <p><strong>Example 3:</strong></p> <pre> <strong>Input:</strong> s = "ab", p = ".*" <strong>Output:</strong> true <strong>Explanation:</strong> ".*" means "zero or more (*) of any character (.)". </pre> <p> </p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 <= s.length <= 20</code></li> <li><code>1 <= p.length <= 30</code></li> <li><code>s</code> contains only lowercase English letters.</li> <li><code>p</code> contains only lowercase English letters, <code>'.'</code>, and <code>'*'</code>.</li> <li>It is guaranteed for each appearance of the character <code>'*'</code>, there will be a previous valid character to match.</li> </ul>