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

bool isMatch(const char* s, const char* p){    if (s == NULL || p == NULL)        return false;    if (*p == ‘\0‘)        return *s == ‘\0‘;    // next char is not ‘*‘    if (*(p+1) != ‘*‘)            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);}

http://leetcode.com/2011/09/regular-expression-matching.html

Regular Expression Matching