Package g0001_0100.s0010_regular_expression_matching

Class Solution

  • 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.

    • Constructor Detail

      • Solution

        public Solution()

    • Method Detail