题解 | #密码验证合格程序#

import java.util.Scanner;

// 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);
        // 注意 hasNext 和 hasNextLine 的区别
        while (in.hasNext()) { // 注意 while 处理多个 case
            String pwd = in.next();
            boolean flag = checkPwd(pwd);
            String outMessage = flag ? "OK" : "NG";
            System.out.println(outMessage);
        }
    }

    private static boolean checkPwd(String pwd) {
        boolean checkLen = checkLen(pwd, 8);
        if (!checkLen) return false;
        boolean checkRule = checkRule(pwd);
        if (!checkRule) return false;
        return checkChild(pwd);
    }

    private static boolean checkChild(String pwd) {
        char[] charArray = pwd.toCharArray();
        for (int i = 0; i < charArray.length - 5; i++) {
            for (int j = i + 3; j < charArray.length - 2; j++) {
                if (charArray[i] == charArray[j] && charArray[i + 1] == charArray[j + 1] && charArray[i + 2] == charArray[j + 2]) {
                    return false;
                }
            }
        }
        return true;
    }

    private static boolean checkRule(String pwd) {
        char[] charArray = pwd.toCharArray();
        int digit = 0, low = 0, upper = 0, other = 0;
        for (int i = 0; i < charArray.length; i++) {
            char ch = charArray[i];
            if (Character.isDigit(ch)) {
                if (digit == 0) {
                    ++digit;
                }
            } else if (Character.isLowerCase(ch)) {
                if (low == 0) {
                    ++low;
                }
            } else if (Character.isUpperCase(ch)) {
                if (upper == 0) {
                    ++upper;
                }
            } else {
                if (other == 0) {
                    ++other;
                }
            }
        }
        return digit + low + upper + other > 2;
    }

    private static boolean checkLen(String pwd, int minLen) {
        return pwd.length() > minLen;
    }
}