Leetcode 44: Wildcard Matching

Implement wildcard pattern matching with support for '?' and '*'.

'?' Matches any single character.
'*' Matches any sequence of characters (including the empty sequence).

The matching should cover the entire input string (not partial).

The function prototype should be:
bool isMatch(const char *s, const char *p)

Some examples:
isMatch("aa","a") → false
isMatch("aa","aa") → true
isMatch("aaa","aa") → false
isMatch("aa", "*") → true
isMatch("aa", "a*") → true
isMatch("ab", "?*") → true
isMatch("aab", "c*a*b") → false

 

 

public class Solution {
    public bool IsMatch(string s, string p) {
        if (s == null || p == null) return s == null && p == null;
        
        int i = 0, j = 0, star = -1, match = -1;
        
        while (i < s.Length)
        {
            if (j < p.Length && (s[i] == p[j] || p[j] == '?'))
            {
                i++;
                j++;
            }
            else if (j < p.Length && p[j] == '*')
            {
                star = j;
                match = i;
                j++;
            }
            else if (star != -1)
            {
                match++;
                i = match;
                j = star + 1;
            }
            else
            {
                return false;
            }
        }
        
        while (j < p.Length)
        {
            if (p[j++] != '*') return false;
        }
        
        return true;
    }
}