How can I get this random method to work?

Question

I have a game that displays patterns on the screen based off order. I don't want this order to be very strict to one order like 1 2 3 4 5 6 I would like the order to be more random. So I am trying to create a method that will generate a random order from 1-6. I tried to create a method that would do so but I failed. Could anyone help me out with that.

P.s. This is in java btw.

public static Random rand = new Random();

public static int[] array = new int[]{0,0,0,0,0,0};

public static void main(String[] args)
{
    for(int i =0;i<6;i++)
    {
        for (int a =0;a<6;a++)
        {
            array[i] = rand.nextInt(6)+1;
            while(array[i] == array[a])
            {
                array[i] = rand.nextInt(6)+1;
            }
        }
    }
}

I did it to check and see if the number i just generated is equal to another number already in the array — Rikupika, Dec 24 '13 at 06:03
@user3131533 You're looking for a permutation. http://stackoverflow.com/q/4240080/279982 might help. — atoMerz, Dec 24 '13 at 06:10
I will tell you an issue with your approach... how do you ensure that the new random number you generated is not already in the list... you loop again... but you cannot keep on doing it all the time.. Hence, better approach is to use collections — AurA, Dec 24 '13 at 06:13

score 3 · Accepted Answer · answered Dec 24 '13 at 06:07

3

create a list of 1-6
use Collections.shuffle() on it
use this list

Sample code:

final List<Integer> list16 = Lists.newArrayList(1,2,3,4,5,6); // guava Lists
Collections.shuffle(list16);
// use list16

or without guava:

final List<Integer> list16 = new ArrayList<Integer>();
for (int i = 1; i < 7; i++) {
    list16.add(i);
}
Collections.shuffle(list16);
// use list16

answered Dec 24 '13 at 06:07

How could I create a list? – Rikupika Dec 24 '13 at 06:09

score 0 · Answer 2 · answered Dec 24 '13 at 06:15

//your no.array say a[6]={0,0,0,0,0,0}

 boolean flag=true;
 int temp=0;
 for(int i=0;i<6;i++)
 {
   while(flag==true)
   {
    temp=rand.nextInt(6);
    if(a[temp]==0)
     {
      array[i] = temp+1; 
      a[temp]=1;
      flag=false;
     }


   }
   flag=true;
  }

score 0 · Answer 3 · answered Dec 24 '13 at 06:36

int num = 6;
    ArrayList<Integer> randomList = new ArrayList<Integer>(); 
    Random rand = new Random();
    for (int i = 0; i < 6; i++) {
        randomList.add(rand.nextInt(6));
    }
     for (int i = 0; i < randomList.size(); i++) {
        System.out.println("numbers  "+randomList.get(i));
    }

How can I get this random method to work?

3 Answers3