Regular Expression Matching

Q:
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

T:
Typical recursive program.

A:

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