void InsertDLink(DuLinkList p,int y)
{
DuLinkList s;
s = (DuLinkList)malloc(sizeof(DuLNode)); //动态创建插入结点s,存储y的值
s ->data = y;
while(p->data != x) //当p的值不为x时,向下查找,直到为x
{
p = p->next;
}
s->prior = p->prior; //把结点s插入到p之前
p->prior ->next = s;
s->next = p;
p->prior = s;
}