lab 11 - Queue.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using ConsoleApplication1;

namespace ConsoleApplication11
{
    class Queue: ICloneable
    {
        #region Fields

        int _capacity;
        int _count;
        Item _firstItem;
        Item _lastItem;

        #endregion Fields
        #region Properties

        public int Count
        {
            get { return _count; }
            set
            {
                if (value < 0)
                {
                    _count = 0;
                }
                else
                {
                    _count = value;
                }
            }
        }
        public int Capacity
        {
            get
            {
                return _capacity;
            }
            set
            {
                if (value < 0)
                {
                    _capacity = 0;
                }
                else
                {
                    _capacity = value;
                }
            }
        }
        public Item FirstItem
        {
            get { return _firstItem; }
            set { _firstItem = value; }
        }
        public Item LastItem
        {
            get { return _lastItem; }
            set { _lastItem = value; }
        }

        #endregion Properties
        #region Constructors

        public Queue()
        {
            Capacity = 100;
            Count = 0;
            FirstItem = null;
            LastItem = null;
        }
        public Queue(int capacity)
        {
            Capacity = capacity;
            Count = 0;
            FirstItem = null;
            LastItem = null;
        }
        public Queue(Queue prototypeQueue)
        {
            Capacity = prototypeQueue.Capacity;
            Count = prototypeQueue.Count;
            FirstItem = prototypeQueue.FirstItem;
            LastItem = prototypeQueue.LastItem;
        }

        #endregion Constructors
        #region Methods

        public bool Contains(object requestedItem)
        {
            if (Count > 0)
            {
                Item currentItem = FirstItem;
                for (int i = 0; i < Count; i++)
                {
                    if (currentItem == requestedItem)
                    {
                        return true;
                    }
                    else
                    {
                        currentItem = currentItem.Next;
                    }
                }
            }
            return false;
        }
        public void Clear()
        {
            Count = 0;
        }
        public void Dequeue()
        {
            if (Count != 0)
            {
                FirstItem = FirstItem.Next;
                Count--;
            }
        }
        public void Enqueue(object data)
        {
            if (Count < Capacity)
            {
                if (Count == 0)
                {
                    FirstItem = new Item(data);
                    LastItem = FirstItem;
                    Count++;
                }
                else
                {
                    LastItem.Next = new Item(data);      // ставим новый элемент после последнего и указываем на него из последнего
                    LastItem = LastItem.Next;            // делаем новый последним
                    Count++;
                }
            }
            else
            {
                Console.WriteLine("Добавление элемента в коллекцию невозможно. Еще один элемент, и ваш ПК пойдет по швам.");
            }
        }
        public object Peek()
        {
            return FirstItem.Data;
        }
        public object[] ToArray()
        {
            if (Count == 0)
            {
                return null;
            }
            else
            {
                object[] array = new object[Count];
                Item currentItem = FirstItem;
                for (int i = 0; i < Count; i++)
                {
                    Item cloneItem = currentItem.Clone() as Item;
                    array[i] = cloneItem.Data;
                }
                return array;
            }
        }
        public object Clone()
        {
            Queue newQueue = new Queue(Capacity);
            if (Count != 0)
            {
                Item currentItem = FirstItem;
                newQueue.Enqueue(currentItem.Data);

                for (int i = 0; i < Count-1; i++)
                {
                    currentItem = currentItem.Next;
                    newQueue.Enqueue(currentItem.Data);
                }
            }
            return newQueue;
        }

        #endregion Methods
    }
}