C实现带头节点带环双向链表的操作

#pragma once

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

typedef char DLinkType;

typedef struct DLinkNode {
DLinkType data;
struct DLinkNode* next;
struct DLinkNode* prev;
} DLinkNode, *linkpoint;

linkpoint Get_NewNode(DLinkType data);//开辟新的节点
void Destory_Node(linkpoint To_Delete);//删除节点
void DLinkListInit(linkpoint* head);//初始化双向链表
void DLinkListPushBack(linkpoint head, DLinkType value);//双向链表尾插
void DLinListPopBack(linkpoint head);//双向链表尾删
void DLinkListDisplay(linkpoint head);//链表打印(顺序和逆序)
void DLinkListPushFront(linkpoint head, DLinkType value);//双向链表头插
void DLinkListPopFront(linkpoint head);//双向链表头删
linkpoint DLinkListFind(linkpoint head, DLinkType to_find);//按照数值寻找节点
void DLinkListInsert(linkpoint pos, DLinkType value);//往指定位置之前插入一个元素
void DLinkListInsertAfter(linkpoint pos, DLinkType value);//往指定位置之后插入一个节点
void DLinkListErase(linkpoint pos);//删除指定位置的节点
void DLinkListRemove(linkpoint head, DLinkType value);//删除指定数值的元素(所有的)
size_t DLinkListSize(linkpoint head);//求双向链表的长度
int DLinkListEmpty(linkpoint head);//判断链表是否为空

#include "Dlinklist.h"

linkpoint Get_NewNode(DLinkType data)//开辟新的节点
{
linkpoint ret = (linkpoint)malloc(sizeof(DLinkNode));
ret->data = data;
ret->next = ret;
ret->prev = ret;
return ret;
}

void Destory_Node(linkpoint To_Delete)//删除节点
{
free(To_Delete);
}

void DLinkListInit(linkpoint* head)//初始化双向链表
{
*head = Get_NewNode('D');
}

void DLinkListPushBack(linkpoint head, DLinkType value)//双向链表尾插
{
if (head == NULL)
{
return;
}
linkpoint New_Tail = Get_NewNode(value);
linkpoint Old_Tail = head->prev;
//New_tail vs head
New_Tail->next = head;
head->prev = New_Tail;
//Old_Tail vs New_Tail
Old_Tail->next = New_Tail;
New_Tail->prev = Old_Tail;
}

void DLinListPopBack(linkpoint head)//双向链表尾删
{
if (head == NULL)//非法输入
{
return;
}
if (head->next == head)//只有空节点
{
return;
}
linkpoint Delete_Tail = head->prev;
linkpoint New_Tail = head->prev->prev;
Destory_Node(Delete_Tail);
//New_Tail vs head
head->prev = New_Tail;
New_Tail->next = head;
}

void DLinkListDisplay(linkpoint head)//链表打印(顺序和逆序)
{
if (head == NULL)//非法输入
{
return;
}
if (head->next == head)//链表为空
{
return;
}
linkpoint cur = head->next;
while (cur != head)
{
printf("%c ", cur->data);
cur = cur->next;
}
printf("\n");
cur = head->prev;
while (cur != head)
{
printf("%c ", cur->data);
cur = cur->prev;
}
}

void DLinkListPushFront(linkpoint head, DLinkType value)//双向链表头插
{
if (head == NULL)//非法输入
{
return;
}
linkpoint New_Head = Get_NewNode(value);
linkpoint Old_Head = head->next;
//head vs New_Head
head->next = New_Head;
New_Head->prev = head;
//New_Head vs Old_Head
New_Head->next = Old_Head;
Old_Head->prev = New_Head;
}

void DLinkListPopFront(linkpoint head)//双向链表头删
{
if (head == NULL)
{
return;
}
if (head->next == head)
{
return;
}
linkpoint To_Delete = head->next;
linkpoint New_Head = head->next->next;
//New_Head vs head
head->next = New_Head;
New_Head->prev = head;
Destory_Node(To_Delete);
}

linkpoint DLinkListFind(linkpoint head, DLinkType to_find)//按照数值寻找节点
{
if (head == NULL)
{
return NULL;
}
if (head->next == head)
{
return NULL;
}
linkpoint cur = head->next;
while (cur != head)
{
if (cur->data == to_find)
{
return cur;
}
cur = cur->next;
}
return NULL;
}

void DLinkListInsert(linkpoint pos, DLinkType value)//往指定位置之前插入一个元素
{
if (pos == NULL)
{
return;
}
linkpoint Before_Pos = pos->prev;
linkpoint New_Node = Get_NewNode(value);
//NewNode vs Before_Pos
Before_Pos->next = New_Node;
New_Node->prev = Before_Pos;
//New_Node vs pos
New_Node->next = pos;
pos->prev = New_Node;
}

void DLinkListInsertAfter(linkpoint pos, DLinkType value)//往指定位置之后插入一个节点
{
if (pos == NULL)
{
return;
}
linkpoint After_pos = pos->next;
linkpoint New_Node = Get_NewNode(value);
//New_Node vs After_pos
New_Node->next = After_pos;
After_pos->prev = New_Node;
//New_Node vs pos
New_Node->prev = pos;
pos->next = New_Node;
}

void DLinkListErase(linkpoint pos)//删除指定位置的节点
{
if (pos == NULL)
{
return;
}
if (pos->next == pos && pos->prev == pos)
{
return;
}
linkpoint Before_pos = pos->prev;
linkpoint After_pos = pos->next;
//Before_pos vs After_pos
Before_pos->next = After_pos;
After_pos->prev = Before_pos;
Destory_Node(pos);
}

void DLinkListRemove(linkpoint head, DLinkType value)//删除指定数值的元素
{
if (head == NULL)
{
return;
}
if (head->next == head && head->prev == head)
{
return;
}
linkpoint cur = head->next;
while (cur != head)
{
linkpoint temp = cur->next;
if (cur->data == value)
{
DLinkListErase(cur);//删除指定位置的节点
}
cur = temp;
}
}

size_t DLinkListSize(linkpoint head)//求双向链表的长度
{
if (head == NULL)
{
return -1;
}
int count = 0;
linkpoint cur = head->next;
while (cur != head)
{
count++;
cur = cur->next;
}
return count;
}

int DLinkListEmpty(linkpoint head)//判断链表是否为空
{
if (head == NULL)
{
return -1;
}
if (head->next == head && head->prev == head)
{
return 0;
}
else
{
return 1;
}
}

#include "Dlinklist.h"

int main()
{
linkpoint head = NULL;
DLinkListInit(&head);//初始化双向链表
DLinListPopBack(head);//双向链表尾删
DLinkListPushBack(head, 'a');//双向链表尾插
DLinkListPushBack(head, 'b');//双向链表尾插
DLinkListPushBack(head, 'c');//双向链表尾插
DLinkListPushBack(head, 'd');//双向链表尾插
DLinkListPushBack(head, 'b');//双向链表尾插
DLinkListPushBack(head, 'b');//双向链表尾插
DLinListPopBack(head);//双向链表尾删
DLinkListDisplay(head);//链表打印(顺序和逆序)
printf("\n");
DLinkListPushFront(head, '8');//双向链表头插7
DLinkListPushFront(head, '7');//双向链表头插
DLinkListPushFront(head, '6');//双向链表头插
DLinkListPopFront(head);//双向链表头删
linkpoint listfind_ret = DLinkListFind(head, 'c');//按照数值寻找节点
DLinkListInsert(listfind_ret, '0');//往指定位置之前插入一个元素
DLinkListInsertAfter(listfind_ret, '1');//往指定位置之后插入一个节点
DLinkListDisplay(head);//链表打印(顺序和逆序)
printf("\n");
DLinkListRemove(head, 'b');//删除指定数值的元素
DLinkListDisplay(head);//链表打印(顺序和逆序)
size_t len_ret = DLinkListSize(head);//求双向链表的长度
int Empty_ret = DLinkListEmpty(head);//判断链表是否为空
if (Empty_ret == -1)
{
printf("输入非法");
}
else if (Empty_ret == 0)
{
printf("链表为空");
}
else
{
printf("链表不为空");
}
system("pause");
return 0;
}