Question

I have an ordered list like this:

var list = new List<String>(){"aaa","aab","aac","baa","bab","bac"};

I want to cut the list in half and reverse the order of the halves, while retaining the order of the two sub lists. The only way I can think of doing that is like this:

var list = new List<String>() { "aaa", "aab", "aac", "baa", "bab", "bac" };
int index = list.IndexOf("aac");
var tempList = new List<String>(list.GetRange(index, list.Count - index));
tempList.AddRange(list.GetRange(0, index));
list = tempList;

This takes 5 lines and a temporary variable, and doesn’t look very nice.

Is there a neater way to do this? I thought that it should be possible with Linq, but most of those methods don’t seem to care about the order of the underlying list.

Any ideas?

Answer 1

This is probably shorter, but it might be slower:

 var list = new List<String> { "aaa", "aab", "aac", "baa", "bab", "bac" };
 var index = list.IndexOf("aac");
 var r = list.Skip(index).Concat(list.Take(index)).ToList();