using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Singly Linked List");

        int i=0;

        Random rnd = new Random();

        Node previous = null;

        Node head = null;

        int numberToSearch = 0;

        int position = rnd.Next(1,6);

        while(i<6){

            Node singlyLinkedList = new Node();

            int data = rnd.Next(10, 100);

​

            singlyLinkedList.data = data;

            if(previous != null)

                previous.next = singlyLinkedList;

            i++;

            if(i == position)

                numberToSearch = data;

            previous = singlyLinkedList;

            if(head == null)

                head = singlyLinkedList;

        }

        PrintNodeList(head);    

        SearchInNode(head, numberToSearch);

        FindMiddleOfNode(head);

        head = AddNodeToTheFront(head, 10);

        PrintNodeList(head);

        head = AddNodeToTheEnd(head, 99);

        PrintNodeList(head);

        head = ReverseList(head);       

        PrintNodeList(head);

        DeleteFirstMatchingNode(head, numberToSearch);

        PrintNodeList(head);

        head = AddNodeToTheFront(head, 10);

        PrintNodeList(head);

        head = DeleteAllMatchingNode(head, 10);

        PrintNodeList(head);

    }

    public static void SearchInNode(Node n, int numberToSearch)

    {   

        Console.WriteLine("\nSearching - " + numberToSearch.ToString());

        while(n.next != null)

        {

            if(n.data == numberToSearch){

                Console.WriteLine("Found- " + n.data.ToString());

            }

            n = n.next;

        }

    }

​

    public static void FindMiddleOfNode(Node head)

    {   

        Console.WriteLine("Find Middle");

        Node fastPointer = head.next;

        Node slowPointer = head;

        while(fastPointer != null && fastPointer.next != null)

        {

            fastPointer = fastPointer.next.next;

            slowPointer = slowPointer.next;

        }

        Console.WriteLine(slowPointer.data.ToString());

    }

    public static void PrintNodeList(Node n)

    {

        Console.WriteLine("Print List");

        while(n != null)

        {

            Console.Write(" " + n.data.ToString());

            n = n.next;

        }

    }

    public static Node AddNodeToTheFront(Node head, int newValue)

    {

        Console.WriteLine("\nAddNodeToTheFront - " + newValue);

        Node newNode = new Node();

        newNode.data = newValue;

        newNode.next = head;

        return newNode;

    }

    public static Node AddNodeToTheEnd(Node head, int newValue)

    {

        Console.WriteLine("\nAddNodeToTheEnd - " + newValue);

        Node newNode = new Node();

        newNode.data = newValue;

        newNode.next = null;

        Node current = head;

        while(current.next != null){

            current = current.next;

        }

        current.next = newNode;

        return head;

    }

    public static Node ReverseList(Node head)

    {

        Console.WriteLine("\nReverseList");

        Node previous = null;

        Node curr = head;

        Node next = null;

        while(curr != null)

        {

            next = curr.next;

            curr.next = previous;

            previous = curr;

            curr = next;

        }

        return previous;

    }

    public static void DeleteFirstMatchingNode(Node head, int dataToDelete)

    {

        Console.WriteLine("\nDeleting Node - " + dataToDelete.ToString());

        Node curr = head;

        Node previous = head;

        while(curr != null && curr.data != dataToDelete)

        {

            previous = curr;

            curr = curr.next;

        }

        if(curr !=null)

        {

            previous.next = curr.next;

        }

    }

    public static Node DeleteAllMatchingNode(Node head, int dataToDelete)

    {

        Console.WriteLine("\nDeleting Node(s) - " + dataToDelete.ToString());

        Node curr = head;

        Node previous = head;

        if(curr.data == dataToDelete)

        {

            Console.Write("found");

            head = curr.next;

        }

        while(curr != null)

        {

            if(curr.data == dataToDelete)

                previous.next = curr.next;

            previous = curr;

            curr = curr.next;

        }

        return head;

    }

    public class Node{

        public int data;

        public Node next;

    }

}