LeetCode OJ：Regular Expression Matching（正则表达式匹配）

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

正则表达式的匹配，注意*代表的不是任意的字符，而是0个或者任意多个前向的字符，代码如下：

 class Solution {
 public:
     bool isMatch(string s, string p) {
            if(p.size() == ) return s.size() == ;
            if(p[] != '*'){
                if(s.size() !=  && (p[] == s[] || p[] == '.'))
                    return isMatch(s.substr(), p.substr());
                return false;
            }else{
                while(s.size() !=  &&(s[] == p[] || p[] == '.')){//模式串匹配0个或者更多的字符
                    if(isMatch(s, p.substr()))
                        return true;
                    s = s.substr();
                }
                return isMatch(s, p.substr());
            }
     }
 };