Obtaining a powerset of a set in Java

Question

The powerset of {1, 2, 3} is:

{{}, {2}, {3}, {2, 3}, {1, 2}, {1, 3}, {1, 2, 3}, {1}}

Let\'s say I have a Set in Java:<

Answer 1

One way without recursion is the following: Use a binary mask and make all the possible combinations.

public HashSet createPowerSet(Object[] array)
{
    HashSet powerSet=new HashSet();
    boolean[] mask= new boolean[array.length];

    for(int i=0;i