Java Array of unique randomly generated integers

Question

public static int[] uniqueRandomElements (int size) {

    int[] a = new int[size];

    for (int i = 0; i < size; i++) {
        a[i] = (int)(Math.random()*10);
         


        

Answer 1

It might work out faster to start with a sequential array and shuffle it. Then they will all be unique by definition.

Take a look at Random shuffling of an array, and at the Collections.shuffle function.

int [] arr = [1,2,3,.....(size)]; //this is pseudo code

Collections.shuffle(arr);// you probably need to convert it to list first