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: 0 <= s.length <= 20 0 <= 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.