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
Solution:
class Solution {
public:
bool isMatch(const char *s, const char *p) {
if (*s == '\0' && *p == '\0') return true;
if (*s == '\0' && *(p+1) == '*') return isMatch(s, p+2);
if (*s == '\0' || *p == '\0') return false;
if (* (p+1) == '*'){
if (*p != *s && *p != '.') return isMatch(s, p+2);
return isMatch(s+1, p) || isMatch(s, p+2);
}
if (*p == '.') return isMatch(s+1, p+1);
if (*s != *p) return false;
return isMatch(s+1, p+1);
}
};
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