Module leetcode_rust::problems::p000_0xx::p000_010

Problem #10 Regular Expression Matching

Description

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 (.)".

Constraints:

• 1 $\leqslant$ s.length $\leqslant$ 20
• 1 $\leqslant$ p.length $\leqslant$ 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.

Source: https://leetcode.com/problems/regular-expression-matching/

Functions

is_match

Simplified regular expression match algorithm