Regular Expression Matching

Given an input string s and a pattern p, implement regular expression matching with support for '.' and '*'.

• '.' matches any single character.
• '*' matches zero or more of the preceding element.

The matching must cover the entire input string, not just a partial match.

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Example 1

Input: s = "aa", p = "a*"
Output: true
Explanation: '*' means zero or more 'a', so "a*" can match "aa".

Example 2

Input: s = "ab", p = ".*"
Output: true
Explanation: ".*" means zero or more of any character, so it matches any string.

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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 that for each occurrence of '*', there will be a valid preceding element.