How to iterate lists with different lengths to find all permutations?

Question

This one should not be too hard but my mind seems to be having a stack overflow (huehue). I have a series of Lists and I want to find all permutations they can be ordered in

Answer 1

Try this:

Func, IEnumerable> combine = null;
combine = xs =>
    xs.Skip(1).Any()
    ? xs.First().SelectMany(x => combine(xs.Skip(1)), (x, y) => String.Format("{0}{1}", x, y))
    : xs.First().Select(x => x.ToString());

var strings = new [] { "AB", "12", "$%" };

foreach (var x in combine(strings))
{
    Console.WriteLine(x);
}

That gives me:

A1$
A1%
A2$
A2%
B1$
B1%
B2$
B2%