private static void permutations(int[] a, int i) {
        if (i > a.length)
            return;
        if (i == a.length) {
            System.out.println(Arrays.toString(a));
            return;
        }

        for (int j = i; j < a.length; j++) {
            int temp = a[i];
            a[i] = a[j];
            a[j] = temp;
            permutations(a, i + 1);
            temp = a[i];
            a[i] = a[j];
            a[j] = temp;
        }
    }
Why Did you create this class? what does it do?
src/codeforces/SubsetGenerator.java