namespace 棧{ interface IStackDS<T>  {  int Count { get; }  int GetLength();  bool IsEmpty();  void Clear();  void Push(T item);  T Pop();  T Peek();   }}

namespace 棧{ class SeqStack<T> : IStackDS<T> {  private T[] data; //棧  private int top; //棧頂  //構造函數  public SeqStack(int size) {   data = new T[size];   top = -1;  }  public SeqStack() : this(10)  {   data = new T[10];   top = -1;  }  //棧的元素個數屬性  public int Count  {   get   {    return top + 1;   }  }  //清空棧的方法  public void Clear()  {   top = -1;  }  //獲取棧的長度的方法  public int GetLength()  {   return Count;  }  //查看棧頂元素是什么  public T Peek()  {   if (top == -1)   {    Console.WriteLine("當前棧沒有元素");    return default(T);   }   return data[top];  }  //出棧（取出棧頂元素，并移除）  public T Pop()  {   T temp = data[top];   top--;   return temp;  }  //入棧  public void Push(T item)  {   data[top + 1] = item;   top++;  }  //棧中是否源元素  public bool IsEmpty()  {   return Count==0;  } }}

namespace 棧{ /// <summary> /// 鏈棧的節點 /// </summary> /// <typeparam name="T"></typeparam> class Node<T> {  private T data; //數據  private Node<T> next; //指向下一個的引用  //四個構造函數，不是都有用，，以及上面兩個變量的屬性，  public Node()  {   data = default(T);   next = null;  }  public Node(T data)  {   this.data = data;   next = null;  }  public Node(T data , Node<T> index)  {   this.data = data;   this.next = index;  }  public Node(Node<T> index)  {   data = default(T);   next = index;  }  public T Data  {   get { return data; }   set { data = value; }  }  public Node<T> Next  {   get { return next; }   set { next = value; }  } }}

using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Threading.Tasks;namespace 棧{ class LinkStark<T> : IStackDS<T> {  private Node<T> top; //棧頂元素節點  private int count = 0; //棧里面的元素  public int Count  {   get   {    return count;   }  }  /// <summary>  /// 清空棧中數據  /// </summary>  public void Clear()  {   count = 0;   top = null;  }  /// <summary>  /// 棧的長度  /// </summary>  /// <returns></returns>  public int GetLength()  {   return Count;  }  /// <summary>  /// 棧中是否有數據  /// </summary>  /// <returns></returns>  public bool IsEmpty()   {   return count == 0;  }  public T Peek()  {   return top.Data;  }  /// <summary>  /// 出棧 取得棧頂元素然后刪除  /// </summary>  /// <returns></returns>  public T Pop()  {   T data = top.Data;   top = top.Next;   count--;   return data;  }  /// <summary>  /// 入棧  /// </summary>  /// <param name="item"></param>  public void Push(T item)  {//把新添加的元素作為頭結點，就是棧頂   Node<T> newNode = new Node<T>(item);   newNode.Next = top;   top = newNode;   count++;  } }}

amespace 棧{ class Program {  static void Main(string[] args)  {   //使用BCL中的棧   //Stack<char> stack = new Stack<char>();   //使用自己的棧   // SeqStack<char> stack = new SeqStack<char>();   //使用自己的鏈棧   IStackDS<char> stack = new LinkStark<char>();   stack.Push('a');   stack.Push('b');   stack.Push('c');   Console.WriteLine("push后的數據個數"+ stack.Count);   char temp = stack.Pop();   Console.WriteLine("pop 之后數據是："+ temp);   Console.WriteLine("pop 之后數據個數"+stack.Count);   char temp2 = stack.Peek();   Console.WriteLine("Peek 之后數據是：" + temp2);   Console.WriteLine("Peek 之后數據個數" + stack.Count);   Console.ReadKey();  } }}