Unique check

Question about the task

Resolved

I already passed the task but can't fully understand the "right solution". In the conditions it states : All generated passwords must be unique. I ensured this condition by just adding all generated passwords to a list and checking for the newly generated password like this:

while(noNumeral || noUppercase || noLowercase || notUnique){
             //more code
            String uniqueCheck =  new String(byteArray);
            if(!uniqueList.contains(uniqueCheck)){
                uniqueList.add(uniqueCheck);
                notUnique = false;
             //more code
}

How did the code in the "right solution" checked for duplicates? I can't find it or don't understand. Thanks in advance.

Comments (3)

Popular
New
Old

You must be signed in to leave a comment

Guadalupe Gagnon

Level 37 , Tampa, United States

25 May 2021, 16:13

They mean that there shouldn't be hard coded passwords in your solution, or "random" numbers generated by the exact same algorithm. I'm not sure how your "check" works because each time the code is run it should return only 1 password, and logically the first password will always be unique as there are no passwords in the unique list. Also, logically, there isn't any way for this code to save a previously used passwords in the validation system when the code is tested multiple times.

Guadalupe Gagnon

Level 37 , Tampa, United States

25 May 2021, 16:56

solution

Take, for example, if there were a task that said create a random string of 20 digits that has to be unique each time it is run; and you passed in this code:

public static void main(String[] s) {
   Random rand = new Random(42);

   StringBuilder sb = new StringBuilder();

   for(int i = 0; i < 20; i++)
      sb.append(rand.nextInt(10));

   System.out.println(sb);
}

This code creates a Random, loops 20 times to add a digit 0-9 each cycle using that Random, then outputs the result. Looks to be good. However, if you run it more than one time, you will notice that the output is not unique. This task is asking that you don't do something like above.

Jurij Thmsn

Level 29 , Flensburg, Germany

26 May 2021, 06:50

Thanks for your answer! In my solution, I just added a static "uniqueList" which stores the passwords outside of the getPassword() method. In a real-life situation I thought the passwords could probably be stored somewhere externally. But of course, theres not really a need for every password to be truly unique and this would slow the program down and probably create security issues. I just interpreted the condition too literally, I guess.