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

代码如下

class Solution {
public:
    bool isMatch(const char *s,const char *p) {
     	if(*p == '\0')
		return *s == '\0';
	if(*(p+1) != '*'){
		if((*p==*s) || ((*p=='.') && (*s!='\0')))
                         return isMatch(s+1,p+1);
		else 
			return false;
	}else{
		while(*s && (*s==*p || *p=='.'))
		{
			if(isMatch(s,p+2))
				return true;
			s++;
		}
		return isMatch(s,p+2);
	}
	return false;
    }
};