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

namespace Test191112
{
    class Program
    {
        static void Main(string[] args)
        {
            Stack st = new Stack();
            st.Push(‘A‘);
            st.Push(‘B‘);
            st.Push(‘C‘);
            st.Push(‘D‘);

            Console.WriteLine("当前堆栈：");
            foreach(char c in st){
                Console.Write(c+" ");
            }
            Console.WriteLine();

            st.Push(‘E‘);
            st.Push(‘F‘);

            Console.WriteLine("栈Stat顶部的元素值是：{0}",st.Peek());
            if (st.Contains(‘D‘))
            {
                Console.WriteLine("栈中已经存在这个元素了！");
            }
            else {
                st.Push(‘0‘);
            }
            Console.WriteLine("当前堆栈：");
            foreach (char c in st)
            {
                Console.Write(c + " ");
            }
            Console.WriteLine();
            st.Pop();
            st.Pop();
            st.Pop();
            Console.WriteLine("当前堆栈：");
            foreach (char c in st)
            {
                Console.Write(c + " ");
            }
            Console.Read();

            

        }
    }
}