[LeetCode] 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)

Example

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:
    /**
     * @param s: A string 
     * @param p: A string includes "." and "*"
     * @return: A boolean
     */
    bool isMatch(const char *s, const char *p) {
        // write your code here
        if(*p == '\0') return *s == '\0';

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