程序代码：

#include <stdio.h>
#include <stdlib.h>

typedef int DataType;
typedef struct node
{
    DataType elem;
    struct node *next;
}*StackNode;
typedef StackNode Stack;

Stack Init_Stack(void)
{
    Stack s;
    s=(struct node*)malloc(sizeof(struct node));
    s->next=NULL;
    return s;
}
int Stack_empty(Stack s)
{
    if (s->next=NULL)
        return 1;
    else
        return 0;
}
void Push(Stack s)
{
    StackNode stack;
    DataType item;
    stack=(struct node*)malloc(sizeof(struct node));
    printf("输入：");
    scanf("%d",&item); 
    stack->elem=item;
    stack->next=s->next;
    s->next=stack;
}
DataType Pop(Stack s)
{
    StackNode temp;
    DataType element;
    if (Stack_empty(s))
    {
        printf("空栈不能出栈！\n");
    }
    else
    {
        temp=s->next;
        s->next=temp->next;
        element=temp->elem;
        free(temp);
        return element;
    }
}
int main(void)
{
    Stack s;
    DataType element;
    s=Init_Stack();
    Push(s);
    Push(s);
    element=Pop(s);
    printf("%d\n",element);
    element=Pop(s);
    printf("%d\n",element);
    element=Pop(s);
    printf("%d\n",element);
    return 0;
}