C# - Java's Deque

Question

in Java, there's a class called Deque, and i would like to find something similar to this in .NET (C#).

The reason i need this, is because i need to peek the last item in the collection, and then dequeue the first one in the collection.

Thanks, AJ Ravindiran.

Answer 1

Check out .NET's System.Collections.Generic.LinkedList collection, which can be used as a Deque. It's a doubly linked list.

Insertion/Deletion

• AddFirst: Add to beginning
• AddLast: Add to end
• RemoveFirst: Remove from beginning. Does not return value.
• RemoveLast: Remove from end. Does not return value.

Peeking:

• First/Last Properties.

  These Return a LinkedListNode<T>, not the actual value. To get the value you have to add .Value to the end.

Answer 2

PowerCollections has a Deque class (and a proven pedigree).

Answer 3

List should do that for you:

var l = new List<int>();
var last = l[l.Count - 1];
l.RemoveAt(0);

Answer 4

Here's my implementation of a Deque<T> (using a ring buffer) and a concurrent lock-free ConcurrentDeque<T>:

• Github: https://github.com/dcastro/DequeNET
• NuGet: https://www.nuget.org/packages/DequeNET/

Both classes support Push, Pop and Peek operations on both ends of the deque, all in O(1) time.

Answer 5

Something like this was touched on in another SO question .

The popular answer seemed to be settling with a linked list, and Eric Lippert suggested his own Deque implementation.

So I guess the short answer is no, there is no such strict data structure built-in in .NET

HTH.