import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Random;

public class RandomArray {
  private static Random rng = new Random();

  public static int[] generate(int size) {
    List<Integer> ints = ints(size);
    int[] result = new int[size];
    int idx = 0;
    while (ints.size() > 0) {
      result[idx++] = ints.remove(random(ints.size()));
    }
    return result;
  }

  private static int random(int n) {
    return rng.nextInt(n);
  }

  // Creates List of size ints from 0-size - 1
  private static List<Integer> ints(int size) {
    List<Integer> ints = new ArrayList<Integer>();
    for (int i = 0; i < size; i++) {
      ints.add(i);
    }
    return ints;
  }

  public static void main(String[] args) {
    System.out.println(Arrays.toString(generate(10)));
  }
}