[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

思路：递归
参考链接：http://blog.csdn.net/hopeztm/article/details/7992253

代码：

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