[pb_freak9666]

So I'm taking a JAVA programming class, but I'm not too good with it. We needed to come up with a random number generator that won't come up with the same number twice, and it can use up to 3 digits. But this is a close as I could get:

import java.util.Random;
/** Generate 10 random integers in the range 0..99. */
public final class RandomInteger {    

       public static final void main(String... aArgs){    
          log("Generating 10 random integers in range 0..99.");        

          //note a single Random object is reused here    
         Random randomGenerator = new Random();    
         for (int idx = 1; idx <= 10; ++idx){      
            int randomInt = randomGenerator.nextInt(100);      
            log("Generated : " + randomInt);    
         }    
    
         log("Done.");  
      }    
        private static void log(String aMessage){    
           System.out.println(aMessage);  
      }
}

Anyone have have any suggestions on how I can tweak this?

EDIT: I'm also using the freeware bluejay to program in JAVA.

[fireisgood4u]

Nuclear decay.

Geiger counter and a household smoke detector.

[pb_freak9666]

What?

[fireisgood4u]

When you use a language's internal random number generator it's 'pseudorandom.' It's generated by software it is not truly random.

Through external hardware you can achieve truly random numbers.

Nuclear decay is random and if you can measure it voila. So get crackin on that nuclear reactor.

Where are you stuck at? I don't know Java but I can provide C pseudocode if that'd help give you ideas.

[pb_freak9666]

What I've wrote so far, is just for a single digit, I need it to be randomized up to 3. And so it can't use the same number sequence twice. Which I have no idea how to do.

[boomslang]

Add generated numbers to a queue, look through the queue to determine if you've already generated that number?

[pb_freak9666]

That's the thing, this is as much as I know...

[PbGoods]

I was working on something similar but in C++.

Basically here is the pseudocode of the program:

Generate random numbers.
Store the random numbers into an array or however you want to store them.
Have a temp variable that take the value of one of the random numbers.
Check to see if this number exists as a duplicate
If number is not a duplicate, continue to check the rest of the numbers.
If number is a duplicate reassign that variable with a new value.

Hope that makes sense.

Edit: You can also check Google for "Java: non repeating random numbers"

[pb_freak9666]

Thanks for the help guys. I got all of it written, with the exeption of an GUI, I don't know how to create a form with just a textbox and button in BlueJ.

[Darth Bagel]

It can't do the same *number* twice or it can't do the same *sequence* twice? The two are very different. If it's number, you'll need to use the queue. If it's sequence, just seed it with the current time.