双向循环单链表
//函数声明：#include"cirtwowaylinklist.h"
#define _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>
#include<stdlib.h>
typedef int ElemType;
typedef struct CirDulNode
{
struct CirDulNode *prior;
ElemType data;
struct CirDulNode *next;
}DulNode;
void judgement_NULL(DulNode *head);
DulNode * creat(); //创建链表
void insert(DulNode *head, int i, ElemType x); //插入结点
void delete_element(DulNode *head, ElemType x); //删除链表中所有值为X的结点
void delete_place(DulNode *head, int i); //删除链表中第i个结点
void find_place(DulNode *head, ElemType x); //寻找链表中所有x，所在的结点位置
void find_element(DulNode *head, int i); //寻找第i个结点上的值
void length(DulNode *head);
void initslinklist(DulNode *head); //释放整个链表
void sortrank(DulNode *head); //对链表进行排序
void output_order(DulNode *head); //正序打印
void output_back(DulNode *head); //逆序打印
int means(); //选择方式
//函数实现：#include"cirtwowaylinklist.c"
#include"cirtwowaylinklist.h"
void judgement_NULL(DulNode *head) //判断动态内存是否开辟成功
{
if (head == NULL)
{
perror("out of memory\n");
exit(EXIT_FAILURE);
}
}
DulNode * creat()
{
DulNode *head, *p, *r;
ElemType x;
head = (DulNode *)malloc(sizeof(DulNode));
judgement_NULL(head);
r = head;
printf("开始建立：");
while (1)
{
scanf("%d", &x);
if (x != 0) //建立链表，以0作为结束标志
{
p = (DulNode *)malloc(sizeof(DulNode));
judgement_NULL(p);
p->data = x;
r->next = p;
p->prior = r;
r = p;
}
else
break;
}
head->prior = r; //将链表首尾链接
r->next = head;
printf("创建成功\n");
return head;
}
void insert(DulNode *head, int i, ElemType x) //在i位置上插入一个X,因为链表循环，所以i>1就一定能找到一个位置
{
DulNode *p, *r;
p = (DulNode *)malloc(sizeof(DulNode));
judgement_NULL(p);
p->data = x;
r = head;
while (1)
{
if (i <= 1)
break;
r = r->next;
i--;
}
if (i < 1)
printf("没有该结点\n");
else
{
p->next = r->next; //在头结点之前，之后都可以插入
p->prior = r;
r->next = p;
p->next->prior = p;
}
}
void delete_element(DulNode *head, ElemType x) //删除链表中所有的x元素所在的结点
{
DulNode *p, *r;
int count = 0;
p = head->next;
while (p != head)
{
if (p->data == x)
{
count++;
r = p;
p = p->next;
r->prior->next = r->next;
r->next->prior = r->prior;
free(r);
r = NULL;
}
else
p = p->next;
}
if (count == 0)
printf("链表中没有此元素\n");
else
printf("共删除%d个\n", count);
}
void delete_place(DulNode *head, int i) //删除一个指定位置的结点，结点位置i>0
{
DulNode *p;
p = head;
while (1)
{
if (i <= 1)
break;
p = p->next;
i--;
}
if (i < 1)
printf("没有该结点\n");
else
{
if (p->next = head) //如果要删除的结点是头结点则跳过删除头结点之后的结点
{
p = head->next;
head->next = p->next;
p->next->prior = head;
}
else
{
p->prior->next = p->next;
p->next->prior = p->prior;
free(p);
}
}
}
void find_place(DulNode *head, ElemType x) //找到链表中所有的x元素所在的结点位置
{
int count = 0;
int flag = 0;
DulNode *p;
p = head->next;
while (p != head)
{
count++;
if (p->data == x)
{
flag++;
printf("此元素结点位置：%d\n", count);
}
p = p->next;
}
if (flag == 0)
printf("链表中没有此元素\n");
}
void find_element(DulNode *head, int i) //找到i结点上的元素，并输出
{
DulNode *p;
p = head->next;
while (p != head)
{
if (i <= 1)
break;
p = p->next;
i--;
}
if (p == head || i != 1)
printf("没有该结点\n");
else
printf("此结点元素：%d\n", p->data);
}
void length(DulNode *head)
{
int len = 0;
DulNode *p;
p = head->next;
while (p != head)
{
len++;
p = p->next;
}
printf("链表长度:%d\n", len);
}
void initslinklist(DulNode *head) //释放整个链表
{
DulNode *p;
p = head->next;
while (p != head)
{
p = p->next;
free(p->prior);
p->prior = NULL;
}
free(head);
head = NULL;
p = NULL;
}
void sortrank(DulNode *head) //对整个链表进行排序
{
DulNode *p, *r;
ElemType tmp;
p = head->next;
while (p->next!= head) //冒泡排序
{
r = head->next;
while (r->next!= head)
{
if ((r->data) >(r->next->data))
{
tmp = r->data;
r->data = r->next->data;
r->next->data = tmp;
}
r = r->next;
}
p=p->next;
}
printf("排序成功\n");
}
void output_order(DulNode *head) //正向打印整个链表
{
DulNode *p;
p = head;
if (head->next == head)
printf("链表为空\n");
else
{
printf("正序打印链表：");
p = p->next;
while (p != head)
{
printf("%d ", p->data);
p = p->next;
}
printf("\n");
}
}
void output_back(DulNode *head) //反向打印整个链表
{
DulNode *p;
p = head->prior;
if (head->next == head)
printf("链表为空\n");
else
{
printf("反向打印链表：");
while (p != head)
{
printf("%d ", p->data);
p = p->prior;
}
printf("\n");
}
}
int means() //选择以哪种方式进行操作
{
int m = 0;
while (1)
{
printf("请选择方式：");
scanf("%d", &m);
if (m == 1 || m == 2)
break;
printf("选择无效，请重新选择\n");
}
return m;
}
//函数测试：
#include"cirtwowaylinklist.h"
int main()
{
DulNode *ret = NULL;
int n = 0;
int i = 0;
ElemType x;
printf("*********************************************\n");
printf("*********************************************\n");
printf("*1.CreatLinkList 2.Insert **********\n");
printf("*3.Delete 4.Find **********\n");
printf("*5.Length 6.Output **********\n");
printf("*7.InitsLinkLinst 8.Sortrank **********\n");
printf("*0.Exit *********************\n\n\n");
while (1)
{
printf("请选择功能：");
scanf("%d", &n);
if (n == 0) //选择0直接退出
{
free(ret); //退出前先释放列表
exit(1);
}
if (ret == NULL) //如果ret为空，则首先建立链表
{
if (n == 1)
{
printf("创建链表以0作为结束标志\n");
ret = creat();
}
else
printf("请先建立链表\n");
}
else
{
switch (n) //选择剩下的功能
{
case 1: //当ret不为空时不能建立链表
printf("当前链表未结束，请先初始化链表\n");
break;
case 2:
printf("请输入要插入的元素和位置：");
scanf("%d", &x);
scanf("%d", &i);
insert(ret, i, x);
break;
case 3:
printf("*1.delete_element 2.delete_place*\n");
if (means() == 1)
{
printf("请输入要删除的元素：");
scanf("%d", &x);
delete_element(ret, x);
}
else
{
printf("请输入要删除的结点：");
scanf("%d", &i);
delete_place(ret, i);
}
break;
case 4:
printf("*1.find_place 2.find_element*\n");
if (means() == 1)
{
printf("请输入要查找的元素：");
scanf("%d", &x);
find_place(ret, x);
}
else
{
printf("请输入要查找的位置：");
scanf("%d", &i);
find_element(ret, i);
}
break;
case 5:
length(ret);
break;
case 6:
printf("*1.output_order 2.output_back*\n");
if (means() == 1)
output_order(ret);
else
output_back(ret);
break;
case 7: //将当前链表释放
initslinklist(ret);
ret = NULL;
break;
case 8:
sortrank(ret);
break;
default:
printf("选择无效，请重新选择\n");
break;
} //switch()语句结束
}
n = 0;
} //循环结束
system("pause");
return 0;
}
