【数据结构作业—02】双链表

2.实现下述要求的Locate运算的函数

问题描述

设有一个带表头结点的双向链表L，每个结点有4个数据成员：指向前驱结点的指针prior、指向后继结点的指针next、存放数据的成员data和访问频度freq。所有结点的freq初始时都为0。每当在链表上进行一次Locate (L, x)操作时，令元素值为x的结点的访问频度freq加1，并将该结点前移，链接到与它的访问频度相等的结点后面（如果该结点没有找到与它访问频度相等的结点，链接到表头后面结点），使得链表中所有结点，保持按访问频度递减的顺序排列，以使频繁访问的结点总是靠近表头。

解决方案要求

输入参数：

1. 输入n，n表示双向链表L的长度，L中的结点的data域依次为1到n。
2. 随机多次调用Locate函数，输入x（调用函数次数由用户决定）。

输出参数：

调用Locate函数结束后，从头结点开始依次输出链表L中个结点的内容（data+freq）。

参考样例：

代码：

  1 #include "stdlib.h"
  2 #include <iostream>
  3 using namespace std;
  4
  5 typedef int ListData;
  6 typedef struct DoubleNode {
  7     ListData data, frequency;
  8     struct DoubleNode *prior, *next;
  9 }DoubleNode, *DoubleList;
 10
 11 void CreateDoubleList (DoubleList &first) {
 12     first = (DoubleNode*)malloc(sizeof(DoubleNode));
 13     if(first == NULL)    {
 14         cout << "存储分配错误！" << endl;
 15         exit(1);
 16     }
 17     first->prior = first->next = first;
 18 }
 19
 20 void IniteList(DoubleList &first, ListData n)    {
 21     DoubleNode *carrier, *temp = first;
 22     for (int i = 0; i < n; i++)    {
 23         carrier = (DoubleNode*)malloc(sizeof(DoubleNode));
 24         carrier->data = i + 1;
 25         carrier->frequency = 0;
 26         //Insert
 27         carrier->prior = temp;
 28         temp->next = carrier;
 29         carrier->next = first;
 30         carrier->next->prior = carrier;
 31
 32         temp = carrier;
 33     }
 34 }
 35
 36 DoubleList Locate(DoubleList &first, ListData x, ListData n)    {
 37     DoubleNode *temp = first->next;
 38     while(temp->data != x && temp != first)    {
 39         temp = temp->next;
 40     }
 41     if (temp == first)    {
 42         cout << "Please input number range from " << 1 << " to " << n << endl;
 43         exit(1);
 44     }
 45     else
 46         return temp;
 47 }
 48
 49 void SortList(DoubleList &first, ListData x, ListData n)    {
 50     DoubleNode *temp;
 51     temp = Locate(first, x, n);
 52     int tempNumber;
 53     temp->frequency++;
 54     if (temp->prior != first)    {
 55         while (temp->frequency > temp->prior->frequency)    {
 56             //SWAP
 57             tempNumber = temp->prior->data;
 58             temp->prior->data = temp->data;
 59             temp->data = tempNumber;
 60             //cout << "temp->prior->data " << temp->prior->data << endl;
 61             //cout << "temp->data " << temp->data << endl;
 62
 63             tempNumber = temp->prior->frequency;
 64             temp->prior->frequency = temp->frequency;
 65             temp->frequency = tempNumber;
 66             //cout << "temp->prior->frequency " << temp->prior->frequency << endl;
 67             //cout << "temp->frequency " << temp->frequency << endl;
 68         }
 69     }
 70 }
 71
 72 int main()    {
 73     int n;
 74     cout << "Please input the link list length:" << endl;
 75     cin >> n;
 76
 77     cout << "The link list data are" << endl;
 78     for (int i = 0; i < n; i++)
 79         cout << "The   " << i + 1 << " node is   " << i + 1 << ", its frequency is 0." << endl;
 80
 81     cout << "Let‘s start to test Locate Function.(-1 meansstopping input number)" << endl;
 82
 83     DoubleList first;
 84     CreateDoubleList(first);
 85     IniteList(first, n);
 86
 87     int x = 0;
 88     while(1)    {
 89         cout << "Please input number :";
 90         cin >> x;
 91         if (x != -1) {
 92             SortList(first, x, n);
 93         }
 94         else    break;
 95
 96
 97     }
 98     cout << "After test, the link list data are:" << endl;
 99     DoubleNode *temp = first->next;
100     int count = 0;
101     while(temp != first)    {
102         count++;
103         cout << "The   " << count << " node is   " << temp->data
104             << ", its frequency is " << temp->frequency << "." << endl;
105         temp = temp->next;
106     }
107
108     return 0;
109 }