C# LINQ combinatorics: All Combinations of a Set without the Empty Set

Question

I have a set of strings, and I want to find all possible combinations of the strings and add them to a list. I want to end up with a list of a list of each combination of th

Answer 1

Providing that all the values in the list are unique:

  List <String> list = new List<String> { "a", "b", "c" };

  var result = Enumerable
    .Range(1, (1 << list.Count) - 1)
    .Select(index => list.Where((item, idx) => ((1 << idx) & index) != 0).ToList());

To print out:

Console.WriteLine(String
  .Join(Environment.NewLine, result
     .Select(line => String.Join(", ", line))));

The outcome is

a
b
a, b
c
a, c
b, c
a, b, c