题解 | #密码验证合格程序#

import java.util.*;
public class Main{
    public static void main(String[] args){
        Scanner in = new Scanner(System.in);
        while(in.hasNext()){
            ensurePass(in.nextLine());
        }

    }
    
    public static void ensurePass(String ss){
        boolean flag = true;
        int f1 = 0,f2 = 0,f3 = 0,f4 = 0;
        //判断是否满足条件1
        if(ss.length() < 9){
            System.out.println("NG");
            return;
        }
        //判断是否满足条件2
        for(char ch : ss.toCharArray()){
            if(f1 + f2 + f3 + f4 >= 3){
                break;
            }
            if(Character.isDigit(ch)){
                f1=1;
            }else if(ch >= 'a' && ch <= 'z'){
                f2=1;
            }else if(ch >= 'A' && ch <='Z'){
                f3=1;
            }else if(ch == ' ' || ch == '\n'){
                flag = false;
                break;
            }else{
                f4=1;
            }
        }
        //判断是否满足条件3
        flag = getString(ss,0,3);
        
        if(flag){
            System.out.println("OK");
        }else{
            System.out.println("NG");
        }
        
    }
    
    // 校验是否有重复子串
    private static boolean getString(String str, int l, int r) {
        if (r >= str.length()) {
            return true;
        }
        if (str.substring(r).contains(str.substring(l, r))) {
            return false;
        } else {
            return getString(str,l+1,r+1);
        }
    }
}