public class Solution
extends Object
10 - Regular Expression Matching\.
Hard
Given an input string `s` and a pattern `p`, implement regular expression matching with support for `'.'` and `'*'` where:
* `'.'` Matches any single character.
* `'*'` Matches zero or more of the preceding element.
The matching should cover the **entire** input string (not partial).
**Example 1:**
**Input:** s = "aa", p = "a"
**Output:** false
**Explanation:** "a" does not match the entire string "aa".
**Example 2:**
**Input:** s = "aa", p = "a\*"
**Output:** true
**Explanation:** '\*' means zero or more of the preceding element, 'a'. Therefore, by repeating 'a' once, it becomes "aa".
**Example 3:**
**Input:** s = "ab", p = ".\*"
**Output:** true
**Explanation:** ".\*" means "zero or more (\*) of any character (.)".
**Example 4:**
**Input:** s = "aab", p = "c\*a\*b"
**Output:** true
**Explanation:** c can be repeated 0 times, a can be repeated 1 time. Therefore, it matches "aab".
**Example 5:**
**Input:** s = "mississippi", p = "mis\*is\*p\*."
**Output:** false
**Constraints:**
* `1 <= s.length <= 20`
* `1 <= p.length <= 30`
* `s` contains only lowercase English letters.
* `p` contains only lowercase English letters, `'.'`, and `'*'`.
* It is guaranteed for each appearance of the character `'*'`, there will be a previous valid character to match.