#include<stdio.h>
#include<malloc.h>
typedef int SElemType;                    //元素类型
typedef int Status;                        //返回值类型
#define OK 1                            //操作成功
#define ERROR 0                            //操作失败

typedef struct StackNode                //链栈结点结构体
{
    SElemType date;                        //节点数据
    struct StackNode *next;                //节点指针
}*LinkStackPtr;                            //结点名

typedef struct LinkStack                //链栈结构体
{
    LinkStackPtr top;                    //栈顶指针
    int count;                            //栈结点数量
}LinkStack;                                //栈名

/*链栈的入栈操作*/
Status Push(LinkStack *S, SElemType e)
{
    LinkStackPtr s = (LinkStackPtr)malloc(sizeof(StackNode));        //申请新结点
    s->date = e;                            //新结点的数据等于e
    s->next = S->top;                        //新结点的下一结点等于现在的栈顶结点
    S->top = s;                                //栈顶结点等于新结点
    S->count++;                                //栈中数据加1
    return OK;
}

/*链栈的出栈操作*/
Status Pop(LinkStack *S, SElemType *e)
{
    if(S->count == 0)                //判断栈是否为空
        return ERROR;
    LinkStackPtr s = (LinkStackPtr)malloc(sizeof(StackNode));        //申请新结点
    s = S->top;                        //新结点等于当前栈顶结点
    *e = s->date;                    //e等于栈顶结点的数据
    S->top = s->next;                //栈顶等于新结点的下一结点
    free(s);                        //释放新结点
    S->count--;                        //栈中数据减1
    return OK;
}

void main()
{
    LinkStack S;            //创建栈L
    S.count = 0;            //栈顶指针为-1,栈为空
    int e;                //入栈与出栈的元素

    while(true)
    {
        printf("请选择对链栈的操作：\n");
        printf("1.入栈\n");
        printf("2.出栈\n");
        printf("3.退出\n");
        int a;
        scanf("%d", &a);
        switch(a)
        {
            case 1:
                printf("请输入入栈的元素：");
                scanf("%d", &e);
                if(Push(&S, e))
                    printf("入栈成功\n");
                else
                    printf("入栈失败\n");
                break;
            case 2:
                if(Pop(&S, &e))
                    printf("出栈的元素为：%d\n",e);
                else
                    printf("栈空\n");
                break;
            case 3:
                return;
            default:
                printf("选择错误\n");
                break;
        }
    }
}