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

 解题思路：当碰到*的时候，需要记录下*的位置，之后如果不匹配的情况下，需要将pattern中的指针指向*号的下一个位置。然后在s中找到第一个与*的下一个位置相同的字母。

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