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

Here is an adaptation of the code provided by Marvin Mendes in this answer but refactored into a single method with an iterator block.

public static IEnumerable> Subsets(IEnumerable source)
{
    List list = source.ToList();
    int length = list.Count;
    int max = (int)Math.Pow(2, list.Count);

    for (int count = 0; count < max; count++)
    {
        List subset = new List();
        uint rs = 0;
        while (rs < length)
        {
            if ((count & (1u << (int)rs)) > 0)
            {
                subset.Add(list[(int)rs]);
            }
            rs++;
        }
        yield return subset;
    }
}