Getting all possible combinations from a list of numbers

Question

I\'m looking for an efficient way to achieve this:

• you have a list of numbers 1.....n (typically: 1..5 or 1..7 or so - reasonably small, but can vary from c

Answer 1

Not my code, but you're looking for the powerset. Google gave me this solution, which seems t work:

public IEnumerable> GetPowerSet(List list)
{
    return from m in Enumerable.Range(0, 1 << list.Count)
              select
                  from i in Enumerable.Range(0, list.Count)
                  where (m & (1 << i)) != 0
                  select list[i];
}

Source: http://rosettacode.org/wiki/Power_set#C.23