美团笔试密码匹配

不知道什么边界没有考虑到，只能AC91%

import java.util.Scanner;
public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        while (sc.hasNext()) {
            int n = sc.nextInt();
            sc.nextLine();
            String[] str = new String[n];
            for (int i = 0; i < n; i ++) {
                 str[i] = sc.nextLine();
            }        
            for (int i = 0; i < n; i ++ ) {
                 System.out.println(match(str[i]));

            }                 
        }
    }
    public static String match(String str) {
          String res = null;
          if (str.length() < 8) {
              res = "NO";
          } else {
              String regex = "^[^0-9]\\w*";

              if (!str.matches("[0-9A-Za-z]+")) {
                  res = "NO";
              } else if (!str.matches(regex)) {
                  res = "NO";
              } else if (str.matches("\\w*[0-9]+\\w*") && (str.matches("\\w*[a-z]+\\w*") || str.matches("\\w*[A-Z]+\\w*"))){
                  res = "YES";

              } else {
                  res = "NO";
              }
          }
          return res;
    }        
}