44. Wildcard Matching

description:

匹配字符串,具体看例子
Given an input string (s) and a pattern (p), 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:

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 = "*a*b"
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

answer:

class Solution {
public:
    bool isMatch(string s, string p) {
        int i = 0, j = 0, iStar = -1, jStar = -1;
        while (i < s.size()) {
            if (s[i] == p[j] || p[j] == '?') {
                ++i; ++j;
            } else if (p[j] == '*') {
                iStar = i;
                jStar = j++; // 这里是先标记位置,然后在挪动 j index
            } else if (iStar >= 0) {
                i = ++iStar; //这里一定是++iStar,而不是 iStar+1,因为不但要挪,还要改变 iStar
                j = jStar + 1;
            } else return false;
        }
        while (j < p.size() && p[j] == '*') ++j;
        return j == p.size();
    }
};

relative point get√:

hint :

两个都从头开始走,一样就继续,不一样就三种可能,一种是‘?’,继续;一种是'*',标记完位置之后上边字符串不变,下边走一步(先假设'*'是空,然后往后走,走到不行了再用这个开挂神器);最后一种就是真的不一样,这个时候就想起来看之前有没有'*',有的话,就用'*'去匹配上边的,一直匹配到上边出现某个字符和下边‘*’右边那个字符一样,然后继续开始之前正常的运作。最后上边的字符都匹配完了,如果下面字符还剩下了,还不是‘*’,那也是失败。

原文地址:https://www.cnblogs.com/forPrometheus-jun/p/11193209.html