Status InsertList(DListLink L,int i,ElemType e)
{
DListLink p,s;
if(iListLength(L)+1) /* i值不合法 */
return ERROR;
int j=1;
p=L->next;
if(!p)
return ERROR;
while(p!=L&&j
{
p=p->next;
j++;
}
if(p==L||j>i-1)
return ERROR;
s=(DListLink)malloc(sizeof(DLNode));
if(!s)
return ERROR;
s->data=e;
s->prior=p;
s->next=p->next;
p->next->prior=s;
p->next=s;
return OK;
}
Status DeleteList(DListLink L,int i)
{
if(iListLength(L))
return ERROR;
int j=1;
DListLink p;
p=L->next;
while(p!=L&&j
{
p=p->next;
j++;
}
if(p==L||j>i)
return ERROR;
p->next->prior=p->prior;
p->prior->next=p->next;
free(p);
return OK;
}
void ListShow(DListLink L)
{
DListLink p;
p=L->next;
int i=1;
while(p!=L)
{
if(i!=1)
printf(" ");
printf("%d",p->data);
p=p->next;
i++;
}
printf("\n");
}
int main()
{
DListLink L;
InitList(&L);
int a,i,e;
while(scanf("%d",&a)!=EOF)
{
if(a==0)
ListShow(L);
else if(a==1)
{
scanf("%d%d",&i,&e);
InsertList(L,i,e);
}
else if(a=2)
{
scanf("%d",&i);
DeleteList(L,i);
}
}
return 0;
}
