Java TreeMap equivalent in C#?

Question

Most places I've consulted say to use SortedList, but the problem is that the program I'm porting actually uses duplicate keys (differentiated by order), which is permissible with TreeMap, but not SortedList.

Any advice?

Disbursement

Answer 1

Does SortedDictionary class help?

Tower

The SortedDictionary will not work because it throws ArgumentException on duplicate keys. As the OP said, duplicate keys will be present. – Recapture

Just use SortedDictionary<of TKey, of TValue>.Item[TKey] property setter, it replaces value if the key is already in a tree. – Paedogenesis

@Leonid Vasilev: That doesn't work either, because then you'll have one item too few in the dictionary, which can cause malfunctions. e.g. happend to me when translating github.com/matsim-up/freight-sa/blob/master/src/main/java/org/… to C# – Partridgeberry

Answer 2

Another great implementation of a Red Black Tree in .NET can be found here: http://www.itu.dk/research/c5/

Sadyesaechao

Answer 3

I don't think C# has one natively. However there are plenty of examples of Red-Black implementations out there. Here is one:-

http://www.codeproject.com/KB/recipes/redblackcs.aspx

Andalusite

Answer 4

Generally use the sorted set

public class ItemComparer : IComparer<int[]>
{
    public int Compare(int[] item1, int[] item2)
    {
        if (item1[0] != item2[0]) return item1[0].CompareTo(item2[0]);
        return item1[1].CompareTo(item2[1]);
    }
}
var s = new SortedSet<int[]>(new ItemComparer());

Jamaaljamaica