[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)

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

思考：难度4.9，参考这里。

bool isMatch(const char *s, const char *p)
{  
	assert(s && p);  
	if (*p == '\0') return *s == '\0';
	// next char is not '*': must match current character  
	if (*(p+1) != '*') 
	{   
		assert(*p != '*'); 
		return ((*p == *s) || (*p == '.' && *s != '\0')) && isMatch(s+1, p+1);  } 
	// next char is '*' 
	while ((*p == *s) || (*p == '.' && *s != '\0'))
	{    
		if (isMatch(s, p+2)) return true;  
		s++;  
	}  
	return isMatch(s, p+2);
}