using System;

public class Program

{

    public class LinkList<T> where T : IEquatable<T>

    {

        private T Data;

        private LinkList<T> Next;

        private LinkList<T> Head;

        public void AddNode(T data)

        {

            LinkList<T> node = new LinkList<T>();

            node.Data = data;

            node.Next = null;

​

            if(this.Head == null)

            {   

                this.Head = node;

            }

            else

            {

                LinkList<T> tracker = this.Head;

                while(tracker.Next != null)

                {

                    tracker = tracker.Next;

                }

                tracker.Next = node;

            }

            this.PrintList();

        }

        public void RemoveNode(T data)

        {

            LinkList<T> tracker = this.Head;

            LinkList<T> prevNode = null;

            if(this.Head != null)

            {

                if(this.Head.Data.Equals(data))

                {

                    tracker = tracker.Next;

                    this.Head = tracker;

                    this.PrintList();

                    return;

                }

​

                while(tracker != null && !tracker.Data.Equals(data))

                {

                    prevNode = tracker;

                    tracker = tracker.Next;

                }

​

                if(tracker != null)

                {

                    prevNode.Next = tracker.Next;

                    tracker = null;

                    this.PrintList();

                    return;

                }

            }

            Console.WriteLine($"Node with data {data} not found..");

            this.PrintList();

        }

        public void ReverseList()

        {

            if(this.Head != null)

            {

                LinkList<T> tracker = this.Head;

                LinkList<T> prev = null;

​

                while(this.Head.Next != null)

                {

                    this.Head = this.Head.Next;

                    tracker.Next = prev;

                    prev = tracker;

                    tracker = this.Head;

                }

                this.Head.Next = prev;

            }

            this.PrintList();

        }

        public void PrintList()

        {

            Console.WriteLine();

            if(this.Head == null)

            {

                Console.WriteLine("No items in the list.");

                return;

            }

            LinkList<T> tracker = this.Head;

            Console.Write("List => ");

            while(tracker != null)

            {

                if(tracker != this.Head)

                {

                    Console.Write(" -> ");

                }

                Console.Write(tracker.Data);

                tracker = tracker.Next;

            }

            Console.WriteLine();

        }

    }

    public static void Main()

    {

        LinkList<int> list = new LinkList<int>();

        int choice = 0;

        while(choice != 5)

        {

            Console.WriteLine();

            Console.WriteLine("1. Add node");

            Console.WriteLine("2. Remove node");

            Console.WriteLine("3. Print list");

            Console.WriteLine("4. Reverse list");

            Console.WriteLine("5. Exist");

            Console.WriteLine();

            Console.WriteLine("Enter your choice: ");

            if(!Int32.TryParse(Console.ReadLine(), out choice))

            {

                Console.WriteLine("Invalid value, try again...");

                continue;

            }

            int input;

            switch(choice)

            {

                case 1: 

                    Console.WriteLine("Enter value to add: ");

                    if(!Int32.TryParse(Console.ReadLine(), out input))

                    {

                        Console.WriteLine("Invalid value, try again...");

                        continue;

                    }

                    list.AddNode(input);

                    break;

                case 2:

                    Console.WriteLine("Enter value to remove: ");

                    if(!Int32.TryParse(Console.ReadLine(), out input))

                    {

                        Console.WriteLine("Invalid value, try again...");

                        continue;

                    }

                    list.RemoveNode(input);

                    break;

                case 3:

                    list.PrintList();

                    break;

                case 4:

                    list.ReverseList();

                    break;

                default:

                    Console.WriteLine("Invalid value, try again...");

                    break;

            }

        }

        Console.WriteLine("Exited...");

    }

}