双链表的创建

typedef struct dnode
{
        int data;
        struct dnode *prior;
        struct dnode *next;
}DNode;

DNode *createDNode(void)
{
        DNode *head = NULL;
        DNode *p = NULL;
        DNode *q = NULL;
        int n = 0;
        int i = 0;

        printf("\n请输入双向链表的长度:");
        scanf("%d",&n);
        if((head=(DNode *)malloc(sizeof(DNode)))==NULL)
        {
                printf("分配内存失败\n");
                exit(0);
        }
        head->data = n;
        head->prior = NULL;
        head->next = NULL;
        p = head;

        printf("请输入这%d个整数，以q结束:\n",n);
        for(i=0; i        {
                if((q=(DNode *)malloc(sizeof(DNode)))==NULL)
                {
                        printf("分配内存失败\n");
                        exit(0);
                }
                scanf("%d\n",&(q->data));
                q->next = NULL;
                p->next = q;
                q->prior = p;
                p = q;
        }
        p->next = NULL;
        p->prior = NULL;
        return head;
}