题解 | #密码验证合格程序#

import java.util.*;
import java.util.regex.*;

public class Main {
    public static void main(String[] arg) {
        Scanner sc = new Scanner(System.in);

        while (sc.hasNext()) {

            String str = sc.next();

            if (getString(str, 0, 3)) {
                System.out.println("NG");
                continue;
            }

            if (str.length() <= 8) {
                System.out.println("NG");
                continue;
            }
            if (getMatch(str)) {
                System.out.println("NG");
                continue;
            }
            System.out.println("OK");
        }
    }

    // 校验是否有重复子串-递归
    private static boolean getString(String str, int l, int r) {
        if (r >= str.length()) {
            return false;
        }

        //021Abc9000
        if (str.substring(r).contains(str.substring(l, r))) {
            return true;
        } else {
            return getString(str, l + 1, r + 1);
        }
    }

    // 检查是否满足正则
    private static boolean getMatch(String str) {
        int count = 0;

        Pattern p1 = Pattern.compile("[A-Z]");
        if (p1.matcher(str).find()) {
            count++;
        }
        Pattern p2 = Pattern.compile("[a-z]");
        if (p2.matcher(str).find()) {
            count++;
        }
        Pattern p3 = Pattern.compile("[0-9]");
        if (p3.matcher(str).find()) {
            count++;
        }
        //存在非以上其他字符
        Pattern p4 = Pattern.compile("[^a-zA-Z0-9]");
        if (p4.matcher(str).find()) {
            count++;
        }

        if (count >= 3) {
            return false;
        } else {
            return true;
        }
    }
}