Android: Check Array for a number Random

Question

I hope you can help me.

I make a game like 4Pics1Word.

I want to load the Level Randomly, I want a loop which generate a Random number from 0 to 10, and then check if the generated number is the first time loaded. If yes write it in an array and end the loop. If the number is not the first time loaded, generate a new random number and check it again until it is not used.

For example this is my code (don´t work right):

Boolean usedImageSet = false;
    for (int t = 0; t <= usedImages.length; t++) {
        if (usedImageSet == false) {
            StringBuilder sb = new StringBuilder();
            sb.append(currentQuestion);
            String used = sb.toString();            

            if (usedImages[t] != null) {
                System.out.println("usedImage" + t
                        + " = not Null, it is" + usedImages[t]);
                if (usedImages[t].equals(used)) {
                    System.out.println("String: "
                            + used
                            + " found it here: [" + t + "]");
                    currentQuestion = (int) (Math.random() * 10);

                }else {
                    System.out.println("String: "
                            + used + " not found");
                }
            }
            if (usedImages[t] == null) {
                usedImages[t] = used;
                System.out.println("useddImage[" + t + "]: "
                        + usedImages[t]);
                System.out.println("usedImage" + t + " is Null, change to"
                        + usedImages[t]);
                usedImageSet = true;
            }
        }

    }

PS: Thank you all, I think the solution from Oren is the best

    // naive implementation
ArrayList<Integer> list = new ArrayList();
for(int i=0; i<10; i++)
{
    list.add(i);
}
Collections.shuffle(list);

// output the generated list
for(int i=0; i<10; i++)
{
    System.out.print(list.get(i));
}

But how can I save the list if I close the game?

Oren · Accepted Answer · 2015-03-10 14:49:39Z

2

You would probably be much better off creating a List of the numbers you want and then calling Collections.shuffle() on that list.

// naive implementation
ArrayList<Integer> list = new ArrayList();
for(int i=0; i<10; i++)
{
    list.add(i);
}
Collections.shuffle(list);

// output the generated list
for(int i=0; i<10; i++)
{
    System.out.print(list.get(i));
}

edited Mar 10, 2015 at 14:49

answered Mar 10, 2015 at 14:44

Oren

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Comments

Xjasz · Accepted Answer · 2015-03-10 14:46:56Z

0

    int oldnumber = 5;
    int newnumber = new Random().nextInt(10);
    while (newnumber == oldnumber){
        newnumber = new Random().nextInt(10);
    }

answered Mar 10, 2015 at 14:46

Xjasz

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