链栈进栈后还显示空栈

Question

链栈的基本操作，前两项是正确的，第三步进栈后，链栈为什么还显示空栈，第三第四步哪里有问题吗？

```c

#include<stdio.h>
#include<malloc.h>
typedef char ElemType;
typedef struct linknode
{
    char data;
    struct linknode *next;
}LinkStNode;
void InitStack(LinkStNode *&s)
{
    s=(LinkStNode *)malloc(sizeof(LinkStNode));
    s->next=NULL;
}
bool StackEmpty(LinkStNode *s)
{
    return(s->next==NULL);
}
bool Push(LinkStNode *&s,char e)
{
    if(s->next==NULL)
      return false;
    LinkStNode *p;
    p=(LinkStNode *)malloc(sizeof(LinkStNode));
    p->data=e;
    p->next=s->next;
    s->next=p;
    return true;
}
int main()
{
    char e; 
    char a[5]={'a','b','c','d','e'};
    LinkStNode *s;
    printf("1.初始化栈\n");
    InitStack(s); 
    StackEmpty(s);
    printf("2.栈是%s栈\n",!StackEmpty(s)?"非空":"空");
    for(int i=0;i<5;i++)
    {
        Push(s,a[i]);
    }
    printf("3.依次进栈abcde\n");
    StackEmpty(s);
    printf("4.栈是%s栈\n",!StackEmpty(s)?"非空":"空");
}

![img](https://img-mid.csdnimg.cn/release/static/image/mid/ask/116180278176140.png "#left")

Answer 1

问题在进栈函数　bool Push(LinkStNode *&s,char e)里　if(s->next==NULL)　return false;　这句里：

bool Push(LinkStNode *&s,char e)
{
    //if(s->next==NULL)
    //  return false;
    LinkStNode *p;
    p=(LinkStNode *)malloc(sizeof(LinkStNode));
    p->data=e;
    p->next=s->next;
    s->next=p;
    return true;
}