[LeetCode] Regular Expression Matching

 

 

class Solution {
public:
    bool isMatch(const char *s, const char *p) {
        int ls = strlen(s);
        int lp = strlen(p);
        if (lp == 0) {
            if (ls != 0) return false;
            else return true;
        }
        if (lp >= 2 && p[1] == '*') {
            int i = 0;
            if (isMatch(s, p+2)) return true;
            while (s[i] == p[0] || p[0] == '.') {
                if (isMatch(s+i+1, p+2)) return true;
                i++;
                if (i >= ls) break;
            }
        } else {
            if (ls > 0 && (s[0] == p[0] || p[0] == '.')) return isMatch(s+1, p+1); 
        }
        return false;
    }
};