[string]Regular Expression Matching

Implement regular expression matching with support for '.' and '*'.

'.' Matches any single character.
'*' Matches zero or more of the preceding element.

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", "a*") → true
isMatch("aa", ".*") → true
isMatch("ab", ".*") → true
isMatch("aab", "c*a*b") → true
class Solution {
public:
    bool isMatch(string& s,int sSize,int startS,string& p,int pSize,int startP)
    {
        if(startS==sSize){
            while(startP<pSize){
                if(p[startP]!='*' && (startP+1>=pSize || p[startP+1]!='*')){
                    break;
                }
                startP++;
            }
            return startP==pSize? true:false;
        }
        if(startP+1<pSize && p[startP+1]=='*'){
            int j=startP+1;
            while(j<pSize && p[j]=='*') j++;
            if(isMatch(s,sSize,startS,p,pSize,j)) return true;
            while(startS<sSize && (s[startS]==p[startP] || p[startP]=='.')){
                if(isMatch(s,sSize,++startS,p,pSize,j)) return true;
            }
            return false;
        }
        if(p[startP]=='.'||p[startP]==s[startS]){
            return isMatch(s,sSize,startS+1,p,pSize,startP+1);
        }
        return false;
    }
    bool isMatch(string s, string p) {
        return isMatch(s,s.size(),0,p,p.size(),0);
    }
};
/*
"aaaaddcbbeefggh"
"a*ddcb*eefc*ggh**"
*/

 通配符匹配:http://www.cnblogs.com/zengzy/p/5019079.html

 

posted @ 2015-12-06 15:53  zengzy  阅读(165)  评论(0)    收藏  举报
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