Create a clear double list

Question

I am trying to create a common doubly linked list and I am having problems with his head. Does anyone have an example of a very simple implementation of a Doubly Linked List using C #?

thanks

Answer 1

Below a simple general double list supporting Add() , an indexer and ToString() - the rest remains as an exercise for the reader - this should give you an idea.

 public class LinkedList<T> { protected LinkedListNode<T> root = null; protected LinkedListNode<T> last = null; public LinkedList() { } public string ToString() { StringBuilder sb = new StringBuilder(); var node = root; while (node != null) { sb.Append("{ " + node.Data.ToString() + " } "); node = node.Next; } return sb.ToString(); } public T this[int index] { get { var node = GetAt(index); if(node == null) throw new ArgumentOutOfRangeException(); return node.Data; } set { var node = GetAt(index); if (node == null) throw new ArgumentOutOfRangeException(); node.Data = value; } } private LinkedListNode<T> GetAt(int index) { var current = root; for(int i=0;i<index;i++) { if (current == null) return null; current = current.Next; } return current; } public void Add(T data) { if (root == null) { root = new LinkedListNode<T>(data); last = root; } else { last.Next = new LinkedListNode<T>(data); last.Next.Previous = last; last = last.Next; } } } public class LinkedListNode<T> { public T Data {get;set;} public LinkedListNode(T data) { Data = data; } public LinkedListNode<T> Next { get; set; } public LinkedListNode<T> Previous { get; set; } } 

Answer 2

System.Collections.Generic.LinkedList<T> is a common doubly linked list. You can refer to the MSDN documentation regarding how it works and what methods / properties should be disclosed.

Answer 3

In addition to MSDN, Wikipedia and Wikibooks have very useful information about the structure and form of Doubly Linked Lists.