算法之递归（3）- 链表操作

        private LNode targetNode = null;private LNode FindLastNthNode(LNode head, int index){if (head.Next == null){return head;}FindLastNthNode(head.Next, index);LNode tmpNode = head;while ((head.Next != null) && (index > 0)){head = head.Next;index--;}if (head.Next == null && index == 0){targetNode = tmpNode;return targetNode;}return targetNode;}

        private LNode targetNode2 = null;private LNode FindLastNthNode2(LNode head, int index){if (head.Next == null)return head;LNode tmpNode = head;while (head != null && index >= 0){head = head.Next;index--;}if (head == null && index == 0){targetNode2 = tmpNode;return targetNode2;}return targetNode2;}

        private int counter = 0;private LNode targetNode2;private LNode FindLastNthNode2(LNode head, int index){if (head.Next == null){counter = index;return head;}FindLastNthNode2(head.Next, index);counter--;if (counter == 0){targetNode2 = head;return targetNode2;}return targetNode2;}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;namespace ConsoleApplication17
{class Program{static void Main(string[] args){Node head = new Node(){Data = "Head"};Node lucas = new Node(){Data = "Lucas"};Node bill = new Node(){Data = "Bill"};Node steve = new Node(){Data = "Steve"};Node anders = new Node(){Data = "Anders"};Node jordan = new Node(){Data = "Jordan"};head.Next = lucas;lucas.Next = bill;bill.Next = steve;steve.Next = anders;anders.Next = jordan;Program p = new Program();Node resultNode = p.FindLastNthNode(head, 2);Console.WriteLine(resultNode.Data);Console.ReadLine();}private Node FindLastNthNode(Node node, int n){if(node == null){return node;}if(n <= 0){throw new ArgumentException("n");}Node node1 = node;Node node2 = node;return this.InternalFindLastNthNode(node1, node2, n);}private Node InternalFindLastNthNode(Node node1, Node node2, int n){if(node1 == null){return node2;}if(n == 0){return this.InternalFindLastNthNode(node1.Next, node2.Next, 0);}return this.InternalFindLastNthNode(node1.Next, node2, --n);}}public class Node{public string Data { get; set; }public Node Next { get; set; }}
}