栈的应用--栈用作判断平衡符号，[()]对的，[(])错的

#include<stdio.h>
#include<stdlib.h>
struct Node;
typedef struct Node *PtrToNode;
typedef PtrToNode Stack;

struct Node{
    char Ele;
    PtrToNode Next;
};

Stack
CreateStack( void )
{
    Stack S;
    S = malloc( sizeof( struct Node ) );
    if(S == NULL )
        printf("out of space");
    S->Next = NULL;
    return S;
}
void
Push(char ch,Stack S)
{
    PtrToNode TmpCell;
    TmpCell = malloc(sizeof( struct Node ));
    if(TmpCell == NULL)
        printf("out of space ");
    else
    {
        TmpCell->Next = S->Next;
        S->Next = TmpCell;
        TmpCell->Ele = ch;
    }
}
int
IsEmpty(Stack S)
{
    return S->Next == NULL;
}
void
Pop( Stack S )
{
    PtrToNode TmpCell;
    TmpCell = S->Next;
    S->Next = TmpCell->Next;
    free(TmpCell);
}
char
Top( Stack S )
{
    return S->Next->Ele;
}

int main()
{
    char Tmp;
    Stack S;
    S = CreateStack();
    while( ( Tmp = getchar() ) != ‘\n‘ )
    {
        if(Tmp == ‘[‘ || Tmp == ‘(‘)
            Push(Tmp,S);
        else if(Tmp == ‘]‘)
        {
            if( !IsEmpty( S ) )
            {
                char tmp;
                tmp = Top( S );
                Pop( S );
                if(tmp != ‘[‘)
                    printf("error");
            }
            else
                printf("Error");
        }//else if
        else
        {
            if( !IsEmpty( S ) )
            {
                char tmp;
                tmp = Top( S );
                Pop( S );
                if(tmp != ‘(‘)
                    printf("error");
            }
            else
                printf("error");
        }//else
    }
    if( !IsEmpty( S ))
        printf("error");
    return 0;
}