How to get all subsets of an array?

Question

Given an array: [dog, cat, mouse]

what is the most elegant way to create:

[,,]
[,,mouse]
[,cat,]
[,cat,mouse]
[dog,,]
[dog,,mouse]
[dog,         


        

Answer 1

Easy to understand version (with descriptions)

I assumed that source = {1,2,3,4}

public static IEnumerable> GetSubSets(IEnumerable source)
    {
        var result = new List>() { new List() }; // empty cluster  added

        for (int i = 0; i < source.Count(); i++)
        {
            var elem = source.Skip(i).Take(1);

            // for elem = 2
            // and currently result = [ [],[1] ]
            var matchUps = result.Select(x => x.Concat(elem));
            //then matchUps => [ [2],[1,2] ]

             result = result.Concat(matchUps).ToList();
            //  matchUps and result concat operation
            // finally result = [ [],[1],[2],[1,2] ]
        }
        return result;
    }