堆栈做了个检验括号是否匹配的程序，不知错哪 。 求指点错在哪里

// 括号匹配.cpp : Defines the entry point for the console application.
//用堆栈的方式实现括号的配对问题

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#define STACK_INIT_SIZE 100       //存储空间初始分量为100
#define STACKINCREMENT 10         //存储空间分配增量为10
#define OVERFLOW -2
#define OK 1
#define ERROR 0

typedef struct stack
{
    char *base;
    char *top;
    int stacksize;
}SqStack;
char InitStack(SqStack &s);
char GetTop(SqStack s,char &e);
char Push(SqStack &s,char e);
char Pop(SqStack &s,char &e);

char InitStack(SqStack &s)  //构造空栈
{
    s.base = (char *)malloc(STACK_INIT_SIZE * sizeof(char));
    if(!s.base)     exit (OVERFLOW);
    s.top = s.base;
    s.stacksize = STACK_INIT_SIZE;
    return OK;
}

char GetTop(SqStack s,char &e)   //判定栈是否为空，若空报错
{
    if(s.top == s.base)   return ERROR;
    e = *(s.top-1);
    return OK;
}

char Push(SqStack &s,char e)               //压栈                                                         
{
    if(s.top -s.base >= s.stacksize)                                                                      // 栈满，加空间
    {
    s.base = (char *)realloc(s.base,(s.stacksize +STACKINCREMENT) * sizeof(char));
    if(!s.base) exit (OVERFLOW);                                                                          //存储分配失败
    s.top = s.base+s.stacksize;
    s.stacksize += STACKINCREMENT;
    }
    *s.top++ = e;
    return OK;
}

char Pop(SqStack &s,char &e)                 //出栈
{
    if(s.top =s.base) return ERROR;
    e = * --s.top;
    return OK;
}



bool BracketsCorrespondency(SqStack &s)
{
    char a[STACK_INIT_SIZE];
    int i=0;
    InitStack(s);
    char x;
    printf("请输入带括号字符串:\n");
    scanf("%s",a);
    while(a[i])
    {
        switch(a[i])
        {
        case '(' : Push(s,a[i]); break;
        case '[' : Push(s,a[i]); break;
        case ')' : GetTop(s,x);
            if (x=='(') Pop(s,x);
            else return ERROR;break;
        case ']' : GetTop(s,x);
            if (x=='[') Pop(s,x);
            else return ERROR;break;
        default:break ;
        }
        i++;
    }
    if(s.stacksize !=0) return ERROR;
    return OK;
}

int main()
{
    SqStack s;
    InitStack(s);
    if(BracketsCorrespondency(s))
        printf("括号匹配\n");
    else
        printf("括号不匹配!\n");
    return 0;   
}

[ 本帖最后由 进击的蛋炒饭 于 2014-5-14 00:17 编辑 ]