算法系列15天速成 第十天 栈

时间:2021-08-17 03:05:46

一: 概念

         栈,同样是一种特殊的线性表,是一种last in first out(lifo)的形式,现实中有很多这样的例子,

     比如:食堂中的一叠盘子,我们只能从顶端一个一个的取。

 

二:存储结构

        ”栈“不像”队列“,需要两个指针来维护,栈只需要一个指针就够了,这得益于栈是一种一端受限的线性表。

      这里同样用”顺序结构“来存储这个”栈“,top指针指向栈顶,所有的操作只能在top处。

         

算法系列15天速成 第十天 栈

代码段:

 

复制代码 代码如下:


#region 栈的数据结构
    /// <summary>
/// 栈的数据结构
/// </summary>
    public class seqstack<t>
    {
        public t[] data;

 

        /// <summary>
/// 栈顶指针
/// </summary>
        public int top = -1;

        public seqstack(int lenth)
        {
            data = new t[lenth];
        }
    }
    #endregion

 


三:常用操作

        栈的操作有:①初始化栈,②入栈,③出栈,④获取栈顶。

1: 初始化栈

        这个还是比较简单的,初始化栈时,设置默认top指针为-1,这个就不用图来展示了。

代码段:

 

复制代码 代码如下:


#region 栈的初始化操作
        /// <summary>
/// 栈的初始化操作
/// </summary>
/// <typeparam name="t"></typeparam>
/// <returns></returns>
        public seqstack<t> seqstackinit<t>(int length)
        {
            seqstack<t> seqstack = new seqstack<t>(length);

 

            seqstack.top = -1;

            return seqstack;
        }
        #endregion

 

2:入栈

       这个操作主要就是做两件事情:① 将元素从栈顶压入,② top指针自增。

算法系列15天速成 第十天 栈

 

代码段:

 

复制代码 代码如下:


#region 入栈
        /// <summary>
/// 入栈
/// </summary>
/// <typeparam name="t"></typeparam>
/// <param name="seqstack"></param>
/// <param name="data"></param>
        public void seqstackpush<t>(seqstack<t> seqstack, t data)
        {
            if (seqstackisfull(seqstack))
                throw new exception("不好意思,栈溢出");

 

            seqstack.data[++seqstack.top] = data;
        }
        #endregion

 

3:出栈

      同样跟“入栈”类似,需要做两件事情,①干掉top处的元素,②top指针自减。

算法系列15天速成 第十天 栈

代码段

 

复制代码 代码如下:


#region 出栈
        /// <summary>
/// 出栈
/// </summary>
/// <typeparam name="t"></typeparam>
/// <param name="seqstack"></param>
/// <returns></returns>
        public t seqstackpop<t>(seqstack<t> seqstack)
        {
            if (seqstackisempty(seqstack))
                throw new exception("呜呜,栈已空");

 

            seqstack.data[seqstack.top] = default(t);

            return seqstack.data[--seqstack.top];
        }
        #endregion

 

4:获取栈顶元素

      这个很简单,跟“出栈”唯一不同的是不破坏栈顶元素,只是翻出来看看而已。

代码段

 

复制代码 代码如下:


#region 获取栈顶
        /// <summary>
/// 获取栈顶
/// </summary>
/// <typeparam name="t"></typeparam>
/// <param name="seqstack"></param>
/// <returns></returns>
        public t seqstackpeek<t>(seqstack<t> seqstack)
        {
            if (seqstackisempty(seqstack))
                throw new exception("栈已空");

 

            return seqstack.data[seqstack.top];
        }
        #endregion

 

总的运行代码如下

 

复制代码 代码如下:


using system;
using system.collections.generic;
using system.linq;
using system.text;

 

namespace seqstack
{
    class program
    {
        static void main(string[] args)
        {
            seqstackclass stackmanager = new seqstackclass();

            seqstack<student> seqstack = stackmanager.seqstackinit<student>(10);

            console.writeline("********************  压入id=1,id=2,id=3的元素  ***********************\n");
            //压入id=1,id=2,id=3的元素
            stackmanager.seqstackpush(seqstack, new student() { id = 1, name = "一线码农", age = 23 });
            stackmanager.seqstackpush(seqstack, new student() { id = 2, name = "huangxincheng520", age = 23 });
            stackmanager.seqstackpush(seqstack, new student() { id = 3, name = "51cto", age = 23 });

            console.writeline(".... 压入成功,当前栈中元素有:" + stackmanager.seqstacklen(seqstack) + "个");

            console.writeline("\n******************  查看栈顶元素  ********************");

            var result = stackmanager.seqstackpeek(seqstack);

            console.writeline("栈顶元素为:id=" + result.id + ",name=" + result.name + ",age=" + result.age);

            console.writeline("\n********************  弹出栈顶元素  ***********************");

            stackmanager.seqstackpop(seqstack);

            console.writeline("\n******************  查看栈中的元素  ********************");

            for (int i = 0; i < stackmanager.seqstacklen(seqstack); i++)
            {
                console.writeline("栈顶元素为:id=" + seqstack.data[i].id + ",name=" + seqstack.data[i].name + ",age=" + seqstack.data[i].age);
            }

            console.read();
        }
    }

    #region 学生数据实体
    /// <summary>
/// 学生数据实体
/// </summary>
    public class student
    {
        public int id { get; set; }

        public string name { get; set; }

        public int age { get; set; }
    }
    #endregion

    #region 栈的数据结构
    /// <summary>
/// 栈的数据结构
/// </summary>
    public class seqstack<t>
    {
        public t[] data;

        /// <summary>
/// 栈顶指针
/// </summary>
        public int top = -1;

        public seqstack(int lenth)
        {
            data = new t[lenth];
        }
    }
    #endregion

    public class seqstackclass
    {
        #region 栈的初始化操作
        /// <summary>
/// 栈的初始化操作
/// </summary>
/// <typeparam name="t"></typeparam>
/// <returns></returns>
        public seqstack<t> seqstackinit<t>(int length)
        {
            seqstack<t> seqstack = new seqstack<t>(length);

            seqstack.top = -1;

            return seqstack;
        }
        #endregion

        #region 判断栈是否为空
        /// <summary>
/// 判断栈是否为空
/// </summary>
/// <typeparam name="t"></typeparam>
/// <param name="seqstack"></param>
/// <returns></returns>
        public bool seqstackisempty<t>(seqstack<t> seqstack)
        {
            return seqstack.top == -1;
        }
        #endregion

        #region 清空栈
        /// <summary>
/// 清空栈
/// </summary>
/// <typeparam name="t"></typeparam>
/// <param name="seqstack"></param>
        public void seqstackclear<t>(seqstack<t> seqstack)
        {
            seqstack.top = -1;
        }
        #endregion

        #region 栈是否已满
        /// <summary>
/// 栈是否已满
/// </summary>
/// <typeparam name="t"></typeparam>
/// <param name="seqstack"></param>
        public bool seqstackisfull<t>(seqstack<t> seqstack)
        {
            return seqstack.top == seqstack.data.length;
        }
        #endregion

        #region 入栈
        /// <summary>
/// 入栈
/// </summary>
/// <typeparam name="t"></typeparam>
/// <param name="seqstack"></param>
/// <param name="data"></param>
        public void seqstackpush<t>(seqstack<t> seqstack, t data)
        {
            if (seqstackisfull(seqstack))
                throw new exception("不好意思,栈溢出");

            seqstack.data[++seqstack.top] = data;
        }
        #endregion

        #region 出栈
        /// <summary>
/// 出栈
/// </summary>
/// <typeparam name="t"></typeparam>
/// <param name="seqstack"></param>
/// <returns></returns>
        public t seqstackpop<t>(seqstack<t> seqstack)
        {
            if (seqstackisempty(seqstack))
                throw new exception("呜呜,栈已空");

            seqstack.data[seqstack.top] = default(t);

            return seqstack.data[--seqstack.top];
        }
        #endregion

        #region 获取栈顶
        /// <summary>
/// 获取栈顶
/// </summary>
/// <typeparam name="t"></typeparam>
/// <param name="seqstack"></param>
/// <returns></returns>
        public t seqstackpeek<t>(seqstack<t> seqstack)
        {
            if (seqstackisempty(seqstack))
                throw new exception("栈已空");

            return seqstack.data[seqstack.top];
        }
        #endregion

        #region 获取栈中元素个数
        /// <summary>
/// 获取栈中元素个数
/// </summary>
/// <typeparam name="t"></typeparam>
/// <param name="seqstack"></param>
/// <returns></returns>
        public int seqstacklen<t>(seqstack<t> seqstack)
        {
            return seqstack.top + 1;
        }
        #endregion
    }
}

 

 

算法系列15天速成 第十天 栈