give me an answer

题目

give me an answer
class Program
{
static void Main(string[] args)
{
LinkedList list = new LinkedList();
list.AddFirst(10);
list.AddLast(20);
list.AddLast(30);
list.AddLast(40);
The above program is incomplete,please complete the above program to perform following operations on linked list,the operations to be performed are:
i.Display total number of nodes into the linked list
ii.Add value :25 after 20.
iii.Add value 5 before 10
iv.Check that the list contains value 30,if contains display a message “30 is into the linked list”
v.Display the values of all the nodes from the linked list.

答案

using System;
using System.Collections.Generic;
using System.Text;

namespace LinkedListDemo
{
class Program
{
static void Main(string[] args)
{
LinkedList<int> list = new LinkedList<int>();

list.AddFirst(10);
            list.AddLast(20);
            list.AddLast(30);
            list.AddLast(40);

//i. Display total number of nodes into the linked list
Console.WriteLine("Total number of nodes:{0}", list.Count);

//ii. Add value : 25 after 20.
list.AddAfter(list.Find(20), 25);

//iii. Add value 5 before 10
list.AddBefore(list.Find(10), 5);

//iv. Check that the list contains value 30, if contains display a message “30 is into the linked list”
if (list.Contains(30)) {
Console.WriteLine("30 is into the linked list");
}

//v. Display the values of all the nodes from the linked list.
foreach (int value in list) {
Console.Write("{0} ", value);
}

Console.ReadKey();

}
}
}