题解 | #密码验证合格程序#

import java.util.Scanner;
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()) {
            String line = in.nextLine();
            if (line.length() <= 8) {
                System.out.println("NG");
                continue;
            }
            if (!pattenMatched(line)) {
                System.out.println("NG");
                continue;
            }
            //判断是否有长度大于等于3的重复子串，只需要判断大小为3就好了；
            boolean find = false;
            //从坐标0开始，不断往右移动窗口；
            for (int i = 0; i < line.length() - 3; i++) {
                //要比对的子串
                String substring = line.substring(i, i + 3);
                //左侧不用比较，之前已经比较过了
                //右侧的字串
                String right = line.substring(i + 3);
                if (right.contains(substring)) {
                    find = true;
                    break;
                }
            }
            if (find) {
                System.out.println("NG");
            } else {
                System.out.println("OK");
            }
        }
    }

    private static boolean pattenMatched(String line) {
        int count = 0;
        Pattern upperCase = Pattern.compile("[A-Z]+");
        Pattern lowerCase = Pattern.compile("[a-z]+");
        Pattern number = Pattern.compile("\\d+");
        Pattern others = Pattern.compile("[^A-Za-z0-9]+");

        if (upperCase.matcher(line).find()) {
            count++;
        }
        if (lowerCase.matcher(line).find()) {
            count++;
        }
        if (number.matcher(line).find()) {
            count++;
        }
        if (others.matcher(line).find()) {
            count++;
        }
        return count >= 3;
    }
}