Fastest way to sort an array without overwriting it

Question

I want to sort an int[] array in Java, but store the sorted array as a new array instead of overwriting it.

The most obvious way to do this seems to be to create a copy of the array and then sort that new array, like so:

int[] a2 = new int[a.length];

for (int i = 0; i < this.length; i++) {
    a2[i] = a[i];
}

Arrays.sort(a2);

However, is there a faster way? Can we sort 'at the same time' as we copy the elements of the old array into the new one?

Answer 1

You could use

int[] a2 = IntStream.of(a).sorted().toArray();

But I doubt it's faster than

int[] a2 = a.clone();
Arrays.sort(a2);

Regardless it's the same complexity, so don't expect more than a constant factor speedup.