C#学习日记 链表

这是一个双向的链表，这个和c、c++中的类似，但是没有指针。也需要小心，因为一不小心就容易索引值溢出，写方法的时候要仔细。

using System;using System.Collections.Generic;namespace Sample{public class MainEntryPoint{static int Main(string[] args){var pdm = new PriorityDocumentManager();pdm.AddDocument(new Document("one","Sample",8));pdm.AddDocument(new Document("two","Sample",3));pdm.AddDocument(new Document("three","Sample",4));pdm.AddDocument(new Document("four","Sample",8));pdm.AddDocument(new Document("five","Sample",1));pdm.AddDocument(new Document("six","Sample",9));pdm.AddDocument(new Document("seven","Sample",1));pdm.AddDocument(new Document("eight","Sample",1));pdm.DisplayAllNodes();return 0;}}public class Document{public string Title{ get; private set;}public string Content{ get; private set;}public int Priority{ get; private set;}public Document(string title, string content, int priority){this.Title = title;this.Content = content;this.Priority = priority;}}public class PriorityDocumentManager{private readonly LinkedList<Document> documentList;//链表的声明private readonly List<LinkedListNode<Document>> priorityNodes;//优先权列表 放每个优先权 最后一个节点public PriorityDocumentManager(){documentList = new LinkedList<Document>();//实例化链表priorityNodes = new List<LinkedListNode<Document>>(10);//实例化列表for(int i = 0; i < 10; i++){priorityNodes.Add(new LinkedListNode<Document>(null));//初始化列表中的元素}}public void AddDocument(Document doc){if(doc == null)throw new ArgumentNullException("doc");AddDocumentToPriorityNode(doc, doc.Priority);}public void AddDocumentToPriorityNode(Document doc, int p){if(p > 9 || p < 0)throw new ArgumentException("Priority must be between 0 and 9");//当优先权的列表相应位置没有元素 就进入if(priorityNodes[p].Value == null){--p;//当优先权大于0的时候 继续调用自己 递归if(p >= 0){AddDocumentToPriorityNode(doc, p);}else{//进入这里说明这个优先权列表在这个优先权之后 全部都为空 此时把元素直接加入//链表的最后即可//把优先权列表的相应节点赋值documentList.AddLast(doc);priorityNodes[doc.Priority] = documentList.Last;}}else{//当这个doc的优先权列表的节点上有值 或者 比它优先权小的节点上有值 就到这里了//把这个有值得节点存到另外一个变量上LinkedListNode<Document> prioNode = priorityNodes[p];if(doc.Priority == p){//当这个优先权的节点上有值 我们将把doc加到它后面//这个优先权的最后一个值就是现在刚加入放入doc的引用documentList.AddAfter( prioNode, doc);priorityNodes[doc.Priority] = prioNode.Next;}else{//当这个优先权的节点比doc的小//需要找到这个节点最前面的那一个节点LinkedListNode<Document> firstNode = prioNode;while(firstNode.Previous != null && firstNode.Previous.Value.Priority == prioNode.Value.Priority){firstNode = prioNode.Previous;prioNode = firstNode;}//把doc节点加在这个最前面的节点之前就可以了//最后需要把优先权节点的值修改成这个doc的引用documentList.AddBefore(firstNode, doc);priorityNodes[doc.Priority] = firstNode.Previous;}}}public void DisplayAllNodes(){foreach(Document doc in documentList){Console.WriteLine("priority {0},title {1}", doc.Priority, doc.Title);}}public Document GetDocument(){Document doc = documentList.First.Value;documentList.RemoveFirst();return doc;}}}