双向链表

http://acm.sdut.edu.cn/sdutoj/showproblem.php?pid=2054&cid=1156

#include<stdio.h>
#include<stdlib.h>
typedef struct node
{
    int data;
    struct node *rb;
    struct node *zb;
}lb;
lb *creat(int n)
{
    lb *head,*p,*tail;
    int i;
    head=(lb *)malloc(sizeof(lb));
    head->rb=NULL;
    head->zb=NULL;
    tail=head;
    for(i=0;i<n;i++)
    {
        p=(lb *)malloc(sizeof(lb));
        scanf("%d",&p->data);
        p->rb=NULL;
        tail->rb=p;
        p->zb=tail;
        tail=p;
    }
    return head;
}
void search(lb *head,int m)
{
    int i,a;
    lb *q,*p;
    for(i=0;i<m;i++)
    {
        scanf("%d",&a);
        p=head->rb;
        while(p!=NULL)
        {
            if(p->data==a)
            {
                q=p;
                if(q==head->rb)
                {
                    printf("%d\n",q->rb->data);
                    break;
                }
                else if(q->rb==NULL)
                {
                    printf("%d\n",q->zb->data);
                    break;
                }
                else
                {printf("%d %d\n",q->zb->data,q->rb->data);break;}
            }
            else
            p=p->rb;
        }
    }
}
int main()
{
    int n,m;
    lb *head;
    scanf("%d %d",&n,&m);
    head=creat(n);
    search(head,m);
    return 0;
}