栈的显示

#include<stdio.h>
#include<stdlib.h>
#define MaxSize 20

typedef char ElemType;

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

void SSInitiate(SeqStack *s)
{
    s->top=-1;
}
int SSIsEmpty(SeqStack *s)
{
    return s->top==-1;
}
int SSIsFull(SeqStack *s)
{
    return s->top==MaxSize-1;
}
void SSPush(SeqStack *s,ElemType x)
{
   
    if(s->top==MaxSize-1)
    {
        printf("栈上溢！\n");
        return;
    }
    s->top++;
    s->data[s->top]=x;
}

void SSPop(SeqStack *s,ElemType *x)
{
    if(s->top==-1)
    {
        printf("栈下溢！\n");
        return;
    }
    *x=s->data[s->top];
    s->top--;
}
int SSGetTop(SeqStack *s,ElemType *topdata)
{
    if(s->data[s->top])
    {
        *topdata=s->data[s->top];
            return 1 ;
    }
    else
        return 0;
}
int StackSize(SeqStack s)
{
    printf("\n栈大小=%d\n",s.top+1);
    return s.top+1;



}
int ExpIsCorrectl(char exp[],int n)
{
    int i;
    ElemType topdata,x;
    SeqStack ss;

    SSInitiate(&ss);
    for(i=0;i<=n;i++)
    {
        if((exp[i]=='(')||(exp[i]=='['||exp[i]=='{'))
        {
            //printf("ss.top=%d",ss.top);
            SSPush(&ss,exp[i]);
            printf("ss.data[%d]=%c",ss.top,ss.data[ss.top]);
         }
        else if(exp[i]==')'&&SSGetTop(&ss,&topdata)==1)
        {
            if(topdata=='(')
            {
                printf("\nss.data[%d]=%c",ss.top,ss.data[ss.top]);
                SSPop(&ss,&x);
            }
            else
                return 0;
        }
        else if(exp[i]==']'&&SSGetTop(&ss,&topdata)==1)
        {
            if(topdata='[')
            {
                printf("\nss.data[%d]=%c",ss.top,ss.data[ss.top]);
                SSPop(&ss,&x);
            }
            return 0;
        }
        else if(exp[i]=='}'&&SSGetTop(&ss,&topdata)==1)
        {
            if(topdata='{')
            {
                printf("\nss.data[%d]=%c",ss.top,ss.data[ss.top]);
                SSPop(&ss,&x);
            }
            return 0;
        }
    }
        printf("\nss.top=%d",ss.top);
        if(ss.top==-1)
            return 1;
        else
            return 0;

}

int _tmain(int argc, _TCHAR* argv[])
{
    char ch[MaxSize];
    int i,last;
    printf("请输入表达式（必须先 有左括号):\n");
    scanf("%s",ch);
    for(i=0;ch[i]!='\0';i++)
        printf("%c",ch[i]);
    last=i-1;
    printf("\nlast=%d\n",last);
    if(ExpIsCorrectl(ch,last)==1)
        printf("\n括号配对\n");
    else
        printf("\n括号不配对\n");
    system("pause");
    return 0;
}

上面是按照书本写的一个栈，但是显示有5个错误！求指教！