数据结构——链栈及其操作

#include<iostream>
using namespace std;

typedef int Status;
typedef int ElemType;
#define OK 1
#define ERROR 0


//链栈的存储结构
typedef struct StackNode
{
    ElemType data;                //数据域
    struct StackNode *next;        //指针域
}StackNode,*LinkStack;


//初始化，构造一个空栈
Status InitStack(LinkStack &S)
{
    S = NULL;
    return OK;
}


//入栈
//在栈顶插入元素e
Status Push(LinkStack &S, ElemType e)
{
    LinkStack p;            //生成新结点
    p = new StackNode;        
    p->data = e;
    p->next = S;            //将新结点插入栈顶
    S = p;                    //修改栈顶指针为p
    return OK;
}


//出栈
//删除S的栈顶元素，用e返回其值
Status Pop(LinkStack &S, ElemType &e)
{
    LinkStack p;
    
    if (S == NULL)        //栈空
        return ERROR;

    e = S->data;    //将栈顶元素赋值给e
    p = S;            //用p临时保存栈顶元素空间，以备释放
    S = S->next;    //修改栈顶指针
    delete p;        //释放原栈顶元素的空间
    return OK;
}


//取栈顶元素
ElemType GetTop(LinkStack S)
{
    if (S != NULL)    //栈非空
        return S->data;        //返回栈顶元素的值，栈顶指针不变
    else
        return ERROR;
}


int main()
{
    int n, x;
    LinkStack S;

    InitStack(S);

    cout << "请输入链栈的元素个数：" << endl;
    cin >> n;

    cout << "请依次输入" << n << "个元素：" << endl;

    while (n--)
    {
        cin >> x;
        Push(S, x);
    }

    cout << "元素依次出栈：" << endl;
    while (S != NULL)
    {
        cout << GetTop(S) << " ";
        Pop(S, x);
    }

    system("pause");
    return 0;
}