请高手指教一下。

#include "stdafx.h"
#include <stdio.h>
#include <malloc.h>
#define MaxSize 100

typedef char ElemType;
typedef struct
{
ElemType data[MaxSize];
int top;
}SqStack;

void InitStack(SqStack *&s)
{
s=(SqStack *)malloc(sizeof(SqStack));
s->top=-1;
}

void ClearStack(SqStack *&s)
{
free(s);
}

int StackLength(SqStack *s)
{
return(s->top+1);
}

int StackEmpty(SqStack *s)
{
return(s->top==-1);
}

int Push(SqStack *&s,ElemType e)
{
if(s->top==MaxSize-1)
return 0;
s->top++;
s->data[s->top]=e;
return 1;
}

int Pop(SqStack *&s,ElemType &e)
{
if(s->top==-1)
return 0;
e=s->data[s->top];
s->top--;
return 1;
}

int GetTop(SqStack *s,ElemType &e)
{
if(s->top==-1)
return 0;
e=s->data[s->top];
return 1;
}

void DispStack(SqStack *s)
{
int i;
for(i=s->top;i>=0;i--)
printf("%c",s->data[i]);
printf("\n");
}

void main()
{
ElemType e;
SqStack *s;
printf("(1)初始化栈s\n");
InitStack(s);
printf("(2)栈为%s\n",(StackEmpty(s)?"空":"非空"));
printf("(3)依次进栈元素啊a,b,c,d,e\n");
Push(s,'a');
Push(s,'b');
Push(s,'c');
Push(s,'d');
Push(s,'e');
printf("(4)栈顶元素为%c\n",GetTop(s,e));
printf("(5)栈为%s\n",(StackEmpty(s)?"空":"非空"));
printf("(6)栈长度:%d\n",StackLength(s));
printf("(7)从栈顶到栈底元素:");DispStack(s);
printf("(8)出栈序列:");
while(!StackEmpty(s))
{
Pop(s,e);
printf("%c",e);
}
printf("\n");
printf("(8)栈为%s\n",(StackEmpty(s)?"空":"非空"));
printf("(9)释放栈\n");
ClearStack(s);
}
问题是 GetTop 输出为什么不是a 而是 一张笑脸