String[] user_ids;

String[] banned_ids;

Set<Set<Integer>> answer;

int n, k;

public int solution(String[] user_id, String[] banned_id) {

user_ids = user_id;

banned_ids = banned_id;

answer = new HashSet<>();

n = user_id.length;

k = banned_id.length;

boolean[] visited = new boolean[n];

search(visited, 0, new ArrayList<>());

// 4

return answer.size();

}

public void search(boolean[] visited, int idx, List<Integer> selected) {

// 2

if (idx == k) {

answer.add(new HashSet<>(selected));

return;

}

for (int i = 0; i < n; i++) {

// 1

if (!visited[i] && isMatch(user_ids[i], banned_ids[idx])) {

visited[i] = true;

selected.add(i);

search(visited, idx + 1, selected);

selected.remove(selected.size() - 1);

visited[i] = false;

}

}

}

// 3

public boolean isMatch(String user, String ban) {

if (user.length() != ban.length()) return false;

for (int i = 0; i < user.length(); i++) {

if (ban.charAt(i) != '*' && ban.charAt(i) != user.charAt(i)) return false;

}

return true;

}

public static void main(String[] args) {

Solution64064 s = new Solution64064();

System.out.println(s.solution(new String[] {"frodo", "fradi", "crodo", "abc123", "frodoc"}, new String[] {"fr*d*", "abc1**"}));

System.out.println(s.solution(new String[] {"frodo", "fradi", "crodo", "abc123", "frodoc"}, new String[] {"*rodo", "*rodo", "******"}));

System.out.println(s.solution(new String[] {"frodo", "fradi", "crodo", "abc123", "frodoc"}, new String[] {"fr*d*", "*rodo", "******", "******"}));

}

}