2012a_82que1

public static boolean isSumOf(int[] a, int n)
    {
        return isSumOf(a, n, 0, "");
    }

    private static boolean isSumOf(int[] a, int n, int i, String res)
    {
        if(n == 0){
            System.out.println(res);
            return true;
        }
        if(i == a.length || n < 0)
            return false;
        return isSumOf(a, n - a[i], i, res + " " + a[i]) || isSumOf(a, n, i + 1, res);
    }