C# 代码实现 顺序队列和链队列

和上篇栈的实现基本是一个思路：
废话不多说，直接写代码吧，，，

//自定义队列接口
namespace 队列
{
    interface IQueue<T>
    {
        int Count { get; }
        int GetLength();
        bool IsEmpty();
        void Clear();
        void Enqueue(T item);
        T Dequeue();
        T Peek();
    }
}

---

//顺序队列的实现类

namespace 队列
{
    class SeqQueue<T> : IQueue<T>
    {
        private T[] data;
        private int count;  //表示当前有几个元素
        private int front;  //队首   （队首索引-1）
        private int rear;   //队尾  （队尾元素索引）

        public SeqQueue(int size)
        {
            data = new T[size];
            count = 0;
            front = -1;
            rear = -1;
        }
        public SeqQueue()
        {
            data = new T[10];
            count = 0;
            front = -1;
            rear = -1;
        }

        public int Count
        {
            get
            {
                return count;
            }
        }

        public void Clear()
        {
            count = 0;
            front = -1;
            rear = -1;
        }

        public T Dequeue()
        {
            if(count > 0)
            {
                T temp = data[front + 1];
                front++;
                count--;
                return temp;
            }
            else
            {
                Console.WriteLine("队列中没有数据，无法取得队首数据");
                return default(T);
            }
        }

        public void Enqueue(T item)
        {
            if (count == data.Length)
            {
                Console.WriteLine("队列元素已满，不可添加");
            }
            else
            {
                if (rear == data.Length -1)  //最后一个位置是否有值
                {
                    data[0] = item;
                    rear = 0;
                    count++;
                }
                else
                {
                    data[rear + 1] = item;
                    rear += 1;
                    count++;
                }

            }
        }

        public int GetLength()
        {
            return count;
        }

        public bool IsEmpty()
        {
            return count == 0;
        }

        public T Peek()
        {
            T temp = data[front + 1];
            return temp;
        }
    }
}

---

//链队列的节点类

namespace 队列
{
    class Node<T> {
        private T data;
        private Node<T> next;

        public Node(T data)
        {
            this.data = data;
        }

        public T Data
        {
            get { return data; }
            set { data = value; }
        }
        public Node<T> Next
        {
            get { return next; }
            set { next = value; }
        }


    }
}

---

//链队列的实现类

namespace 队列
{
    class LinkQueue<T> : IQueue<T>
    {
        private Node<T> front; //头结点
        private Node<T> rear;  //尾结点
        private int count;  //表示元素个数

        public LinkQueue()
        {
            front = null;
            rear = null;
            count = 0;
        }

        public int Count
        {
            get
            {
                return count;
            }
        }

        public void Clear()
        {
            front = null;
            rear = null;
            count = 0;
        }

        public T Dequeue()
        {
            if (count == 0)
            {
                Console.WriteLine("队列为空");
                return default(T);
            }else if(count == 1)
            {
                T temp = front.Data;
                front = rear = null;
                count = 0;
                return temp;
            }
            else
            {
                T temp = front.Data;
                front = front.Next;
                count--;
                return temp;
            }
        }

        public void Enqueue(T item)
        {
            Node<T> newNode = new Node<T>(item);

            if (count == 0)
            {
                front = newNode;
                rear = newNode;
                count = 1;
            }
            else
            {
                rear.Next = newNode;
                rear = newNode;
                count++;
            }
        }

        public int GetLength()
        {
            return count;
        }

        public bool IsEmpty()
        {
            return count == 0;
        }

        public T Peek()
        {
            if (front != null)
            {
                return front.Data;
            }
            else
            {
                return default(T);
            }
        }
    }
}

---

//以上两个实现类的测试类

namespace 队列
{
    class Program
    {
        static void Main(string[] args)
        {
            //CRL中的队列
            //Queue<int> queue = new Queue<int>();

            //自己的写的顺序队列
            //SeqQueue<int> queue = new SeqQueue<int>();

            //自己的链队列
            LinkQueue<int> queue = new LinkQueue<int>();


            queue.Enqueue(12);
            queue.Enqueue(34);
            queue.Enqueue(56);
            queue.Enqueue(78);
            queue.Enqueue(90);

            Console.WriteLine("添加五个元素后的大小："+ queue.Count);

            int i = queue.Dequeue();   //出队（取出并删除）

            Console.WriteLine("取出的元素是： " + i);
            Console.WriteLine("出队后队列大小：" + queue.Count);

            int j = queue.Peek();
            Console.WriteLine("Peek取出的元素是： " + j);
            Console.WriteLine("PeeK后队列大小：" + queue.Count);

            queue.Clear();
            Console.WriteLine("清空后的队列大小：" + queue.Count);

            Console.ReadKey();
        }
    }
}