Question

How to generate random integers but making sure that they don’t ever repeat?

For now I use :

Random randomGenerator = new Random();
randomGenerator.nextInt(100);

EDIT I

I’m looking for most efficient way, or least bad

EDIT II

Range is not important

Answer 1

ArrayList<Integer> list = new ArrayList<Integer>(100);
for(int i = 0; i < 100; i++)
{
  list.add(i);
}
Collections.shuffle(list);

Now, list contains the numbers 0 through 99, but in a random order.