Creating a power set of a Sequence

Question

I am trying to create a program that is a base for creating possible combinations of a sequence, string or a number. This is some sort of encryption / decryption program. I

Answer 1

Same algorithm SergeyS mention using Linq (where inputSet is the input and outputPowerSet is the output):

int setLength = inputSet.Count;
int powerSetLength = 1 << setLength;
for (int bitMask = 0; bitMask < powerSetLength; bitMask++)
{
    var subSet = from x in inputSet 
                 where ((1 << inputSet.IndexOf(x)) & bitMask) != 0 
                 select x;
    outputPowerSet.Add(subSet.ToList());
}