Wildcard Matching Algorithm
In computer science, an algorithm for matching wildcards (also known as globbing) is useful in comparing text strings that may contain wildcard syntax. common uses of these algorithms include command-line interfaces, e.g. the Bourne shell or Microsoft Windows command-line or text editor or file manager, as well as the interfaces for some search engines and databases. Among both recursive and non-recursive algorithms, strategies for performing the shape matching operation vary widely, as evidenced among the variety of example algorithms referenced below. Early algorithms for matching wildcards often relied on recursion, but the technique was criticized on grounds of performance and reliability considerations. Test case development and performance optimization techniques have been demonstrably bring to bear on certain algorithms, particularly those developed by critics of the recursive algorithms.
class Solution {
public:
bool isMatch(const char *s, const char *p) {
// Start typing your C/C++ solution below
// DO NOT write int main() function
if (s == NULL || p == NULL)
return false;
int slen = strlen(s);
int plen = strlen(p);
int count_char = 0;
for (int i = 0; i < plen; i++) {
if (p[i] != '*')
count_char += 1;
}
if (count_char > slen)
return false;
bool matches[slen + 1];
memset(matches, false, sizeof(bool)*(slen+1));
int first_match = 0;
matches[first_match] = true;
for (int i = 0; i < plen; i++) {
if (i > 0 && p[i] == '*' && p[i-1] == '*')
continue;
if (p[i] == '*') {
for (int j = first_match + 1; j <= slen; j++)
matches[j] = true;
} else {
int match_id = -1;
for (int j = slen; j > first_match; j--) {
matches[j] = (s[j-1] == p[i] || p[i] == '?') && matches[j-1];
if (matches[j])
match_id = j;
}
if (match_id != -1)
first_match = match_id;
else
return false;
}
}
return matches[slen];
}
};
