leetcode[10]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(const char *s, const char *p) {
    if (*p=='\0')
        return *s=='\0';
    if (*(p+1)=='*')
    {
        while((*s!='\0')&&((*s==*p)||(*p=='.')))
        {
            if (isMatch(s,p+2))
            {
                return true;
            }
            else
            {
                s++;
            }
        }
        return isMatch(s,p+2);
    } 
    else 
    {
        if((*s!='\0')&&((*s==*p)||(*p=='.')))
        {
            return isMatch(s+1,p+1);
        }
        return false;
    }
    }
};

 

posted @ 2015-02-10 13:49  Vae永Silence  阅读(128)  评论(0编辑  收藏  举报