int[] array1 = new int[1000000], array2 = new int[1000000];
        long start = System.nanoTime();
        for (int i = 1; i < 100000; i++) {
            System.arraycopy(array2, 0, array1, 0, 1000000);
        }
        System.out.println(System.nanoTime() - start);
        start = System.nanoTime();
        for (int i = 1; i < 100000; i++) {
            for (int j = 0; j < 1000000; j++)
                array1[j] = 0;
        }
        System.out.println(System.nanoTime() - start);