数据结构趣题——动态双向链表的使用

#include <stdio.h>
#include <stdlib.h>

typedef struct node {
    int data;
    int freq;
    struct node *prior;
    struct node *next;
} dbLNode, *dbLinkList;

/*创建一个双向链表，返回它的头指针*/
dbLinkList GreatdbLinkList(int n) {
    dbLinkList p, r, list = NULL;
    int e;
    int i;
    list = (dbLinkList)malloc(sizeof(dbLNode));  /*创建头结点head,头结点中不存放内容*/
    list->next = list->prior = NULL;

    for(i = 1; i <= n; i++) {
        scanf("%d", &e);
        p = (dbLinkList)malloc(sizeof(dbLNode));
        p->data = e;
        p->freq = 0;
        p->next = NULL;
        p->prior = NULL;

        if(!list->next) {
            list->next = p;      /*第一个结点*/
            p->prior = list;
        }
        else {
            r->next = p;   /*双向连接下面的结点*/
            p->prior = r;
        }

        r = p;
    }

    return list;
}

/*访问双向链表中指定的结点，并调整结点次序*/
void visit(dbLinkList *l, int x) {
    dbLinkList p = *l, q, r, s;
    p = p->next;   /*p指向第一个结点*/

    while(p->data != x && p != NULL)p = p->next;

    if(p == NULL) {
        printf("Input error!\n");
        return;
    }

    p->freq ++;
    printf("Visiting this node\n");

    while((p->prior) != *l && p->freq > p->prior->freq)
    {

        /*实现双向链表结点的交换*/
        q = p->prior;
        r = p->next;
        s = p->prior->prior;
        p->prior = q->prior;
        p->next = q;
        q->prior = p;
        q->next = r;
        r->prior = q;
        s->next = p;
    }

}

void TransdbLinkList(dbLinkList l)
{   /*遍历整个双向链表,并打印出每个结点中的数据和访问频度*/
    l = l->next;

    while(l != NULL) {
        printf("(data:%d ,freq:%d)--> ", l->data, l->freq);
        l = l->next;
    }

    printf("X\n\n");

}

int main()
{
    dbLinkList l;
    int d;
    printf("Input five integer to creat a doubly link list\n");
    l = GreatdbLinkList(5);
    TransdbLinkList(l);

    printf("Please input the data that you want to vist\n");

    scanf("%d", &d);

    while(d != 0) {
        visit(&l, d);
        TransdbLinkList(l);
        scanf("%d", &d);
    }
    return 0;
}