[Leetcode]10. 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") → falseisMatch("aa","aa") → trueisMatch("aaa","aa") → falseisMatch("aa", "a*") → trueisMatch("aa", ".*") → trueisMatch("ab", ".*") → trueisMatch("aab", "c*a*b") → true

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