Implement Regular Expression matching with support‘.‘
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(const char *s, const char *p) { if (*p == ‘\0‘) return *s == ‘\0‘; //empty if (*(p + 1) != ‘*‘) {//without * if(!matchFirst(s,p)) return false; return isMatch(s + 1, p + 1); } else { //next: with a * if(isMatch(s, p + 2)) return true; //try the length of 0 while ( matchFirst(s,p) ) //try all possible lengths if (isMatch(++s, p + 2)) return true; } }private: bool matchFirst(const char *s, const char *p){ return (*p == *s || (*p == ‘.‘ && *s != ‘\0‘)); }};
[Leetcode] Regular Expression matching (recursion)