1. BCL中顺序栈

    BCL中有Stack，实现了栈的操作。

1.1 Program.cs

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

namespace _402_栈
{
    class Program
    {
        static void Main(string[] args)
        {
            //1.使用BCL中的Stack<T>
            Stack<char> stack = new Stack<char>();
            stack.Push('2');
            stack.Push('6');
            stack.Push('f');
            stack.Push('h');

            Console.WriteLine("Push 后的个数" + stack.Count);

            Console.WriteLine("Pop之前的stack元素：");
            foreach (var temp in stack)
            {
                Console.Write(temp + " ");
            }
            char c = stack.Pop();//取得栈顶数据，并将该数据删除
            Console.WriteLine("Pop之后得到的数据：" + c);
            Console.WriteLine("Pop之后的stack元素：");
            foreach (var temp in stack)
            {
                Console.Write(temp + " ");
            }

            char c2 = stack.Peek();//取得栈顶元素，不删除
            Console.WriteLine("peek得到的数据：" + c2);
            Console.WriteLine("peek后栈中元素个数：" + stack.Count);

            stack.Clear();
            Console.WriteLine("Clear后栈中元素个数：" + stack.Count);
            //Console.WriteLine("空栈时取栈顶元素：" + stack.Peek());//为空栈时不能取栈顶元素，即不能进行peek pop操作，会出错
            Console.ReadKey();
}
}
}

2. 自己实现顺序栈

    定义一个顺序栈的接口IStackDS，再实现接口中的方法。

2.1 IStackDS.cs(接口)

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

namespace _402_栈
{
    interface IStackDS<T>
    {
        int Count { get; }//用来取得数据
        int GetLength();
        bool IsEmpty();
        void Clear();
        void Push(T item);
        T Peek();
        T Pop();
    }
}

2.2 SeqStack.cs(实现接口)

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

namespace _402_栈
{
    class SeqStack<T> : IStackDS<T>
    {
        private T[] data;
        private int top;

        public SeqStack(int size)
        {
            data = new T[size];
            top = -1;
        }
        public SeqStack():this(10)
        {
            
        }
        public int Count {
            get
            {
                return top + 1;
            }
        }
        public void Clear()
        {
            top = -1;
        }

        public int GetLength()
        {
            return Count;
        }

        public bool IsEmpty()
        {
            return top == -1;
        }

        public T Peek()
        {
            return data[top];
        }

        public T Pop()
        {
            T temp = data[top];
            top--;
            return temp;
        }

        public void Push(T item)
        {
            data[top + 1] = item;
            top++;
        }
    }
}

2.3 Program.cs

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

namespace _402_栈
{
    class Program
    {
        static void Main(string[] args)
        {
//2.使用自己定义的顺序栈
            IStackDS<char> stack = new SeqStack<char>(30);
            stack.Push('2');
            stack.Push('6');
            stack.Push('f');
            stack.Push('h');

            Console.WriteLine("Push 后的个数" + stack.Count);

            
            char c = stack.Pop();//取得栈顶数据，并将该数据删除
            Console.WriteLine("Pop之后得到的数据：" + c);

            char c2 = stack.Peek();//取得栈顶元素，不删除
            Console.WriteLine("peek得到的数据：" + c2);
            Console.WriteLine("peek后栈中元素个数：" + stack.Count);

            stack.Clear();
            Console.WriteLine("Clear后栈中元素个数：" + stack.Count);
            Console.ReadKey();
        }
    }
}