双链表的定义

typedef struct DNode
{
    int data;
    struct DNode *prior, *next;
} DNode, *DLinkList;

双链表的插入

bool InsertNextDNode(DNode *p, DNode *s)
{
    if (p == NULL || s == NULL)
    {
        return false;
    }
    s->next = p->next;
    if (p->next != NULL)
    {
        p->next->prior = s;
    }
    p->next = s;
    s->prior = p;
}

双链表的删除

bool DeleteNextDNode(DNode *p)
{
    if (p == NULL)
    {
        return false;
    }
    DNode *q = p->next;
    if (q == NULL)
    {
        return false;
    }
    if (q->next != NULL)
    {
        q->next->prior = p;
    }
    p->next = q->next;
    free(q);
    return true;
}

双链表销毁

void DestoryList(DLinkList &L)
{
    while (L->next != NULL)
    {
        DeleteNextDNode(L);
    }
    free(L);
    L = NULL;
}

双链表的遍历

while (p->next != NULL) //后向遍历
{
    /* code */
    p = p->next;
}
while (p.prior != NULL) //前项遍历
{
    /* code */
    p = p->prior;
}

双链表