题解 | #密码验证合格程序#

import java.util.Scanner;
import java.util.Scanner;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        while(in.hasNext()){
            int category=0;
            String target = in.next();
            //判断长度>8
            if (checkLength((target))){
                System.out.println("NG");
                continue;
            }
            //判断是否包含三种元素
            if (!checkClass(target)){
                System.out.println("NG");
                continue;
            }
            //判断是否有重复子串
            if (checkRule(target,0,3)){
                System.out.println("NG");
                continue;
            }


            System.out.println("OK");
        }
    }

    private static boolean checkRule(String target, int str, int end) {
        if (end >= target.length()) {
            return false;
        }
        if (target.substring(end).contains(target.substring(str, end))) {
            return true;
        } else {
            return checkRule(target, str + 1, end + 1);
        }
    }

    private static boolean checkClass(String str) {
        int count = 0;
        //大写字母
        Pattern p1 = Pattern.compile("[A-Z]");
        if (p1.matcher(str).find()) {
            count++;
        }
        //小写字母
        Pattern p2 = Pattern.compile("[a-z]");
        if (p2.matcher(str).find()) {
            count++;
        }
        //数字
        Pattern p3 = Pattern.compile("[0-9]");
        if (p3.matcher(str).find()) {
            count++;
        }
        //字符
        Pattern p4 = Pattern.compile("[^a-zA-Z0-9\\x0a]");
        if (p4.matcher(str).find()) {
            count++;
        }


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

    private static boolean checkLength(String target) {
        return target.length() <= 8;
    }
}

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