LeetCode -- Regular Expression Matching

'.'

'*'

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