Ex 24 page 122

using System;
using System.Collections.Generic;
using System.Text;
using Unit4.CollectionsLib;

namespace NodeExamples
{
    class Ex24P122
    {
        public static int ReadGrades()
        {
            Node<int> list = null;
            Node<int> pos = null;

            Console.Write("enter grade: ");
            int x = int.Parse(Console.ReadLine());
            while (x != 999)
            {
                // do somthing
                if (list == null)
                {
                    list = new Node<int>(x);
                    pos = list;
                }
                else
                {
                    pos.SetNext(new Node<int>(x));
                    pos = pos.GetNext();
                }
                // get a nuew grade
                Console.Write("enter grade: ");
                x = int.Parse(Console.ReadLine());
            }

            int lastGrade = pos.GetValue();

            int count = 0;
            Node<int> p = list;
            //pos = list;
            while (p != null)
            {
                if (p.GetValue() > lastGrade)
                {
                    count++;
                }
                p = p.GetNext();
            }

            return count;
        }


        public static Node<int> ReadGrades2()
        {
            Node<int> list = null;
            Node<int> pos = null;

            Console.Write("enter grade: ");
            int x = int.Parse(Console.ReadLine());
            while (x != 999)
            {
                // do somthing
                if (list == null)
                {
                    list = new Node<int>(x);
                    pos = list;
                }
                else
                {
                    pos.SetNext(new Node<int>(x));
                    pos = pos.GetNext();
                }
                // get a nuew grade
                Console.Write("enter grade: ");
                x = int.Parse(Console.ReadLine());
            }

            int lastGrade = pos.GetValue();

            Node<int> p = list;
            Node<int> res = null;
            Node<int> last = null;

            while (p != null)
            {
                if (p.GetValue() > lastGrade)
                {
                    if (res == null)
                    {
                        res = new Node<int>(p.GetValue());
                        last = res;
                    }
                    else
                    {
                        last.SetNext(new Node<int>(p.GetValue()));
                        last = last.GetNext();
                    }
                }
                p = p.GetNext();
            }

            return res;
        }

        public static Unit4.CollectionsLib.Stack<int> ReadGrades3()
        {
            Node<int> list = null;
            Node<int> pos = null;

            Console.Write("enter grade: ");
            int x = int.Parse(Console.ReadLine());
            while (x != 999)
            {
                // do somthing
                if (list == null)
                {
                    list = new Node<int>(x);
                    pos = list;
                }
                else
                {
                    pos.SetNext(new Node<int>(x));
                    pos = pos.GetNext();
                }
                // get a nuew grade
                Console.Write("enter grade: ");
                x = int.Parse(Console.ReadLine());
            }

            int lastGrade = pos.GetValue();

            Node<int> p = list;
            Unit4.CollectionsLib.Stack<int> stk = new Unit4.CollectionsLib.Stack<int>();

            while (p != null)
            {
                if (p.GetValue() > lastGrade)
                {
                    stk.Push(p.GetValue());
                }
                p = p.GetNext();
            }

            return stk;
        }
    }
}