6-1 在一个数组中实现两个堆栈 (20分)

Push先S->Data[++(S->Top1)]
Pop后 S->Data[(S->Top1)–]

Stack CreateStack( int MaxSize )
{
   
	struct SNode *S=(struct SNode *)malloc(sizeof(struct SNode));
	S->Data=(int *)malloc(MaxSize*sizeof(int));
	S->Top1=-1;
	S->Top2=MaxSize;
	S->MaxSize=MaxSize;
	return S;
}
bool Push( Stack S, ElementType X, int Tag )
{
   
	if(S->Top1+1==S->Top2)
	{
   
		printf("Stack Full\n");
		return false;
	}
	else
	{
   
		if(Tag==1) S->Data[++(S->Top1)]=X;
		else if(Tag==2) S->Data[--(S->Top2)]=X;
		return true;
	}
}
ElementType Pop( Stack S, int Tag )
{
   
	if(Tag==1)
	{
   
		if(S->Top1==-1)
		{
   
			printf("Stack %d Empty\n",Tag);
			return ERROR;
		}
		else return S->Data[(S->Top1)--];
	}
	else if(Tag==2)
	{
   
		if(S->Top2==S->MaxSize)
		{
   
			printf("Stack %d Empty\n",Tag);
			return ERROR;
		}
		else  return S->Data[(S->Top2)++];
	}
}