Question

i want a program that can add the generated random numbers(unique not repeating) to 2 arrays alternatively…
this is what i have done so far:

int n = 56,m=0;
 int e=0,f=0;
 int[] deck1 = new int[n];
 int[] deck2 = new int[m];
        Random rng = new Random(); 
List<Integer> generated = new ArrayList<Integer>();
for(int i=1;i<=53;i++)
{
    while(true)
    {
        next = rng.nextInt(53) + 1;
        if (!generated.contains(next))
        {
            generated.add(next);
            break;
        } 
    }
   for(int t = 2;t<=i;t++)
   if(t%2==0)
   {deck1[e]=next;e++;}
    else
   {deck2[f]=next;f++;}

    }

but i am not getting the result. please help.
thanks.

Answer 1

You can fix your immediate problem by forgetting about the inner for loop (iterating over t) and instead compute using i:

if ( i % 2 == 0 ) {
    deck1[e] = next;
    e++;
} else {
    //...

The problem is that currently at each iteration of the loop, you add the element to each array many times (up to i times).

Some other suggestions:

• Make generated a Set<Integer> (HashSet<Integer>), it is much better suited to this task
• A better algorithm would be to construct a List<Integer> containing the numbers 1 through 53 and shuffle (e.g. with Collections.shuffle()). Then you could just add the first half of the list to deck1 and the second half to deck2.