【数据结构】链栈

#pragma once
#include<iostream>
#include <stdlib.h>
using namespace std;

#define  Elemtype int
typedef struct Nstack
{
Elemtype data;
Nstack* next;
}Node;//节点

typedef struct
{
Node* top;
int size;
}Lstack;//栈结构

void Init(Lstack *st)
{
st->top = (Node*)malloc(sizeof(Node));
if (!st->top)
return;
st->top->next= NULL;
st->top = NULL;
st->size = 0;
}

void Push(Lstack *st, Elemtype &x)
{
Node* p = (Node*)malloc(sizeof(Node));
if (!p)
return ;
p->data = x;
p->next = st->top;
st->top = p;
st->size++;
}

bool Empty(Lstack *st)
{
return st->size==0;
}

void Pop(Lstack *st, Elemtype&e)
{
if (!Empty(st))
{
cout << "栈为空，不能删除！" << endl;
return;
}
Node*cur = st->top;
e = cur->data;
st->top = st->top->next;
free(cur);
st->size--;
}

void Gettop(Lstack *st,Elemtype &e)
{
if (!Empty(st))
{
cout << "栈为空，没有栈顶元素！" << endl;
return;
}
Node* temp = st->top;
e = st->top->data;
cout << "栈顶元素：" << e << endl;
}

void Length(Lstack *st)
{
cout << "栈长为：" << st->size << endl;
}

void Clear(Lstack *st)
{
if (Empty(st))
return;
st->size = 0;
Node* p=NULL;
while (st->top!=NULL)
{
p = st->top;
st->top = p->next;
free(p);
}
}

void Destroy(Lstack *st)
{
Clear(st);
free(st);
st = NULL;
}

void show(Lstack *st)
{
Node* p = st->top;
while (p)
{
cout << p->data;
p = p->next;
cout << "-->";
}
cout << "栈底"<< endl;
}

#include"Lstack.h"

void main()
{
Lstack q;
Elemtype item;
int select = 1;
while (select)
{
cout << "**********************************" << endl;
cout << "* [1] init        [2] push       *" << endl;
cout << "* [3] gettop      [4] length     *" << endl;
cout << "* [5] pop         [6] clear      *" << endl;
cout << "* [7] destroy     [8] show       *" << endl;
cout << "* [0] quit                       *" << endl;
cout << "**********************************" << endl;
cout << "please chose:>";
cin >> select;
switch (select)
{
case 1:
Init(&q);
break;
case 2:
cout << "请输入要入栈的元素：";
cin >> item;
Push(&q, item);
break;
case 3:
Gettop(&q, item);
break;
case 4:
Length(&q);
break;
case 5:
Pop(&q, item);
cout << "出栈元素为：" << item << endl;
break;
case 6:
Clear(&q);
break;
case 7:
Destroy(&q);
cout<<"栈已经被销毁！不能再插入数据！"<<endl;
return;
case 8:
show(&q);
break;
case 0:
cout << "退出成功！" << endl;
break;
default:
break;
}
}

}