Print All the Subsets of a Given Set (Power Set)

Objective: Given a set of numbers, print all the posssible subsets of it including empty set.

Power Set: In mathematics, PowerSet of any given set S, PS(S) is set of all subsets of S including empty set.
Example:

 S ={1,2,3}

PS(S): {{ᵩ}, {1}, {2}, {3}, {1, 2}, {1, 3}, {2, 3}, {1, 2, 3}}.

Approach:

Create an binary array of the same size as the given array.
Now for every integer we have two options, whether to select it or ignore it.
Now if we select it, we will put 1 in the boolean array at the corresponding index or if we ignore it, put 0 at that index.
Say you have a variable called x, which represents the current index at the given array.
Make x = 0 ( ignoring xth index) and x = 1( selecting xth index) and make recursive

Code:

	public class AllCombinations {

	static int[] B = { 1, 2, 3 };

	public void combinations(int[] A, int x) {
	if (x == A.length – 1) {
	A[x] = 0; // last digit, don't select it
	printArray(A); // print the set
	A[x] = 1; //// last digit, select it
	printArray(A);
	return;
	}
	A[x] = 0; //either you will not select this digit
	combinations(A, x + 1);
	A[x] = 1; //either you will select this digit
	combinations(A, x + 1);
	}

	public void printArray(int[] A) {
	boolean isNULL = true;
	System.out.print("{");
	for (int i = 0; i < B.length; i++) {
	if (A[i] == 1) {
	System.out.print(B[i] + "");
	isNULL = false;
	}
	}
	if (isNULL == false) {
	System.out.print("}");
	System.out.print(" ");
	}

	if (isNULL) {
	System.out.print("Empty");
	System.out.print("} ");
	}
	}

	public static void main(String[] args) {
	AllCombinations a = new AllCombinations();
	int[] A = new int[B.length];
	a.combinations(A, 0);

	}

	}

Output:

{Empty} {3}  {2}  {23}  {1}  {13}  {12}  {123}