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

Solution: Both of the two solutions are from http://leetcode.com/2011/09/regular-expression-matching.html .

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