括号匹配为什么不成功

#include<stdio.h>
#include<stdlib.h>
#include<malloc.h>
#define stack_size 1000
#define stack_increment 10
typedef struct sqstack
{
      char *base;
      char *top;
      int size;
}sqstack;
void IntiStack(sqstack *s)
{
      s->base=(char *)malloc(sizeof(char)*stack_size);
      if(!s->base) printf("分配内存失败!");
      s->top=s->base;
      s->size=stack_size;

}
void Push(sqstack *s,char c)
{
     if(s->top-s->base>=stack_size)
     {
       s->base=(char*)realloc(s->base,(s->size+stack_increment)*sizeof(char));
       if(!s->base) printf("增加空间失败！");
       s->top=s->base+stack_size;
       s->size+=stack_increment;
     }
      *s->top++=c;
 
}
void  Pop(sqstack *s,char e)
{
   if(s->top==s->base) printf("栈为空\n");
   e=*--s->top;
}
int StackEmpty(sqstack *s)
{
    if(s->top!=s->base) return 0;
    return 1;
}
void Bracket(sqstack *s,char *str)
{
  int i=0,flag1=0,flag2;
  char e;
  while(str[i]!='\0'){
    switch(str[i]){
      case '(':Push(s,'(');break; //'('进栈
      case '[':Push(s,'[');break; //'['进栈
      case ')':{Pop(s,e);
                if(e!='(') flag1=1; break;} //出栈，判断是否为'('
      case ']':{Pop(s,e);
                if(e!='[') flag1=1;break;} //出栈，判断是否为'['
      default: break;
    }
    if(flag1) break; //出现不匹配，立即结束循环
    i++;
  }
  flag2=StackEmpty(s); //flag2判断堆栈是否为空
  if(!flag1 && flag2) printf("括号匹配!\n");
  else printf("括号不匹配!\n");
  
}
int main()
{
     sqstack s;char str[100],temp;
     printf("请输入字符串:\n");
     scanf("%s",str);
     scanf("%c",&temp);//接受输入的回车键
     IntiStack(&s);
     Bracket(&s,str);
     return 0;
}