Get all subsets of a collection

Question

I am trying to create a method that will return all subsets of a set.

For example if I have the collection 10,20,30 I will like to get the following ou

Answer 1

This is a basic algorithm which i used the below technique to make a single player scrabble word solver (the newspaper ones).

Let your set have n elements. Increment an integer starting from 0 to 2^n. For each generater number bitmask each position of the integer. If the i th position of the integer is 1 then select the i th element of the set. For each generated integer from 0 to 2^n doing the above bitmasting and selection will get you all the subsets.

Here is a post: http://phoxis.org/2009/10/13/allcombgen/