leetcode 44. Wildcard Matching 贪心

Given an input string (s) and a pattern §, 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).

Note:

s could be empty and contains only lowercase letters a-z.
p could be empty and contains only lowercase letters a-z, and characters like ? or *.
Example 1:

Input:
s = “aa”
p = “a”
Output: false
Explanation: “a” does not match the entire string “aa”.
Example 2:

Input:
s = “aa”
p = ""
Output: true
Explanation: '’ matches any sequence.
Example 3:

Input:
s = “cb”
p = “?a”
Output: false
Explanation: ‘?’ matches ‘c’, but the second letter is ‘a’, which does not match ‘b’.
Example 4:

Input:
s = “adceb”
p = “ab”
Output: true
Explanation: The first ‘’ matches the empty sequence, while the second '’ matches the substring “dce”.
Example 5:

Input:
s = “acdcb”
p = “a*c?b”
Output: false

贪婪算法

class Solution {
public:
    bool isMatch(string s, string p) {
        int m = s.length(), n = p.length();
        int i = 0, j = 0, asterisk = -1, match;
        while (i < m) {
            if (j < n && p[j] == '*') {
                match = i; 
                asterisk = j++;
            }
            else if (j < n && (s[i] == p[j] || p[j] == '?')) {
                i++; 
                j++;
            }
            else if (asterisk >= 0) {
                i = ++match;
                j = asterisk + 1;
            }
            else return false;
        }
        while (j < n && p[j] == '*') j++;
        return j == n;
    }
};