题解 | #密码验证合格程序#

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

/**
 * HJ20 密码验证合格程序
 * @author d3y1
 */
public class Main {
    // 长度
    private static final int LEN = 8;
    // 种类
    private static final int K = 3;
    // 窗口大小
    private static final int W = 3;

    public static void main(String[] args) {
        // solution1();
        solution2();
    }

    /**
     * 字符串 + 哈希
     */
    private static void solution1(){
        Scanner in = new Scanner(System.in);
        while (in.hasNextLine()) {
            String password = in.nextLine();
            int n = password.length();

            // 空格
            if(password.contains(" ")){
                System.out.println("NG");
                continue;
            }
            
            // 长度
            if(n <= LEN){
                System.out.println("NG");
                continue;
            }

            // 种类
            HashSet<String> kindSet = new HashSet<>();
            for(char ch: password.toCharArray()){
                if(Character.isUpperCase(ch)){
                    kindSet.add("upper");
                }
                else if(Character.isLowerCase(ch)){
                    kindSet.add("lower");
                }
                else if(Character.isDigit(ch)){
                    kindSet.add("digit");
                }
                else{
                    kindSet.add("other");
                }
            }
            if(kindSet.size() < K){
                System.out.println("NG");
                continue;
            }

            // 重复
            String sub;
            boolean isDuplicated = false;
            for(int i=0; i+W<n; i++){
                sub = password.substring(i, i+W);
                if(password.substring(i+W).contains(sub)){
                    isDuplicated = true;
                    break;
                }
            }
            if(isDuplicated){
                System.out.println("NG");
                continue;
            }

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

    /**
     * 字符串 + 正则
     */
    private static void solution2(){
        Scanner in = new Scanner(System.in);
        while (in.hasNextLine()) {
            String password = in.nextLine();
            int n = password.length();

            // 空格
            if(password.contains(" ")){
                System.out.println("NG");
                continue;
            }
            
            // 长度
            if(n <= LEN){
                System.out.println("NG");
                continue;
            }
            
            // 种类
            if(!isKindMatch(password)){
                System.out.println("NG");
                continue;
            }
            
            // 重复
            String sub;
            boolean isDuplicated = false;
            for(int i=0; i+W<n; i++){
                sub = password.substring(i, i+W);
                if(password.substring(i+W).contains(sub)){
                    isDuplicated = true;
                    break;
                }
            }
            if(isDuplicated){
                System.out.println("NG");
                continue;
            }

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

    /**
     * 种类校验: 正则
     * @param password
     * @return
     */
    private static boolean isKindMatch(String password){
        int kind = 0;

        Pattern p1 = Pattern.compile("[A-Z]");
        if(p1.matcher(password).find()){
            kind++;
        }
        Pattern p2 = Pattern.compile("[a-z]");
        if(p2.matcher(password).find()){
            kind++;
        }
        Pattern p3 = Pattern.compile("[0-9]");
        if(p3.matcher(password).find()){
            kind++;
        }
        Pattern p4 = Pattern.compile("[^A-Za-z0-9]");
        if(p4.matcher(password).find()){
            kind++;
        }

        if(kind < K){
            return false;
        }

        return true;
    }
}