C#实现顺序栈和链栈

顺序栈和链栈分别类似于顺序表和单链表，只是由于栈的First In Last Out性质，其操作相对简单，是顺序表和单链表的子集。

链栈中的链不使用Head属性，这一属性是多余的，使用链栈类的TopNode属性即可。另外，为了避免每次返回链栈的长度都要遍历所有结点，在链栈类中增加Num属性，Push操作时，Num自加，Pop操作时，Num自减，始终等于链栈中的结点数。

 

using System;using System.Collections.Generic;using System.Linq;using System.Text;namespace Stack{ //栈的接口 public interface IStackDS<T> { int GetLength(); bool IsEmpty(); void Clear(); void Push(T t); T Pop(); T GetTop(); } //顺序栈类 class SequenceStack<T> : IStackDS<T> { private int intMaxSize; private int intTopPointer; private T[] tData; public int MaxSize { get { return this.intMaxSize; } set { this.intMaxSize = value; } } public int TopPointer//没有set，不应该在类外修改top的Pointer { get { return this.intTopPointer; } } public T this[int i]//没有set，不支持类外修改 { get { return this.tData[i]; } } public SequenceStack():this(100)//默认MaxSize为100 { } public SequenceStack(int size) { this.tData = new T[size]; this.intMaxSize = size; this.intTopPointer = -1;//栈为空时，top的pointer为-1 } #region IStackDS<T> 成员 public int GetLength() { return this.intTopPointer+1; } public bool IsEmpty() { return this.intTopPointer == -1; } public void Clear() { this.intTopPointer = -1; } public void Push(T t) { this.intTopPointer++; this.tData[this.intTopPointer] = t; } public T Pop() { if (this.IsEmpty()) { Console.WriteLine("The stack has no elements!"); return default(T); } else { T t = this.tData[this.intTopPointer]; this.intTopPointer--; return t; } } public T GetTop() { if (this.IsEmpty()) { Console.WriteLine("The stack has no elements!"); return default(T); } else { return this.tData[this.intTopPointer]; } } #endregion } //链栈的结点类 class Node<T> { private T tVal; private Node<T> tNext; public T Val { get { return this.tVal; } set { this.tVal = value; } } public Node<T> Next { get { return this.tNext; } set { this.tNext = value; } } public Node() { this.tVal = default(T); this.tNext = null; } public Node(T t) { this.tVal = t; this.tNext = null; } } //链栈类。不设置里面链表的head属性，因为这是多余的。用TopNode表示栈顶即可。 //另，为了避免返回长度时对链表遍历，使用num计数，使num与栈内的结点个数同时变化。 class LinkedStack<T>:IStackDS<T> { private Node<T> nTopNode; private int intNum; public Node<T> TopNode { get { return this.nTopNode; } set { this.nTopNode = value; } } public int Num { get { return this.intNum; } set { this.intNum = value; } } public LinkedStack() { this.nTopNode = null; this.intNum = 0; } public LinkedStack(Node<T> node) { this.nTopNode = node; this.intNum = 1; } #region IStackDS<T> 成员 public int GetLength() { return this.intNum; } public bool IsEmpty() { return this.intNum == 0; } public void Clear() { this.nTopNode = null; this.intNum = 0; } public void Push(T t) { Node<T> node = new Node<T>(t); node.Next = this.nTopNode;//无论TopNode是否为null，都可以直接赋，无需判断是否为null this.nTopNode = node; this.intNum++; } public T Pop() { if (this.IsEmpty()) { Console.WriteLine("The stack has no elements!"); return default(T); } else { Node<T> node = this.nTopNode; this.nTopNode = this.nTopNode.Next; this.intNum--; return node.Val; } } public T GetTop() { if (this.IsEmpty()) { Console.WriteLine("The stack has no elements!"); return default(T); } else { Node<T> node = this.nTopNode; return node.Val; } } #endregion } class Program { static void Main(string[] args) { SequenceStack<int> stack = new SequenceStack<int>(10); stack.Push(3); stack.Push(9); while (!stack.IsEmpty()) { int i = stack.Pop(); Console.WriteLine(i); } Console.ReadLine(); LinkedStack<int> stack2 = new LinkedStack<int>(); stack2.Push(3); stack2.Push(9); while (!stack2.IsEmpty()) { int i = stack2.Pop(); Console.WriteLine(i); } Console.ReadLine(); } }}