括号匹配检验

#include<stdio.h>
#include<stdlib.h>
#define STACK_SIZE 100 
#define overflow -2
#define OK  1
#define TRUE  1
#define FALSE 0
typedef char datatype;  
typedef int Status; 
typedef struct         
{datatype  *base;      
datatype *top;          
int stacksize;         
} seqstack;            
void Initial(seqstack *S) 
{ 
S->base=(datatype*)malloc(STACK_SIZE *sizeof(datatype));
if(!S->base)
exit (-1);
S->top=S->base;
S->stacksize=STACK_SIZE;
}
Status DestroyStack(seqstack *S)
{
 free(S->base);
 S->base=NULL;
 S->top=NULL;
 S->stacksize=0;
 return OK;
}
Status ClearStack(seqstack *S)
{S->top=S->base;
 S->stacksize=STACK_SIZE;
return OK;
}
Status StackEmpty(seqstack *S) 
{
 if(S->top==S->base)
  return TRUE;
 else
  return FALSE;
}
datatype  GetTop(seqstack S) 
{datatype  e;
 e=*(S.top-1);
 return e;
}

int IsEmpty(seqstack *S)  
{
 return S->top==S->base;
}
int IsFull (seqstack *S)  
{
 return S->top-S->base==STACK_SIZE-1;
}
void Push(seqstack *S,datatype x) 
{
if(IsFull(S))
{
 printf("overflow"); 
exit (1);
}
else
*S->top++=x;           
}
void Pop(seqstack *S)   
{
 if(IsEmpty(S))
{
printf("NULL");
exit (1);
}
else
--S->top;            
}
datatype Top(seqstack *S) 
{if(IsEmpty(S))
{
 printf("empty");   
exit  (1);
}
return *(S->top-1);
}
int match (seqstack *S,char *str) 
{
char x;
int i, flag=1;
for(i=0;str[i]!='\0';i++)
{
switch(str[i])
{
case '(' : Push(S,'(');
break;
case '[' : Push(S,'[');
break;
case '{' : Push(S,'{');
break;
case ')' : x=Top(S);
           Pop(S);
     if(x!='(')
      flag=0;
break;
case ']' : x=Top(S);
           Pop(S);
     if(x!='[')
      flag=0;
break;
case '}' : x=Top(S);
           Pop(S);
     if(x!='{')
      flag=0;
break;
}
if(!flag)
break;
}
if(IsEmpty(S)==1 && flag)
return 1;
else
return 0;
 }
int main ()
{
	int t;
	scanf("%d%*c",&t);
	while(t--){
	seqstack S,*st;
	st=&S;
	char str[100];

	Initial(st);
	
	gets(str);
	
	if(match(st,str))
	printf ("ok\n");
	else
	printf ("error\n");
	}
	return 0;
}