双向循环链表的实现

/********************************************************************************************************
*
*	file name:	Zqh_链表.c
* 	author	 :	keyword2024@163.com
* 	date	 :	2024/05/05
*	function :	链表的增删改查
*	note	 :	模板
*	
*  Copyright (c)  2023-2025   keyword2024@163.com    All right Reserved
* ******************************************************************************************************/#include <stdbool.h>
#include <stdlib.h>
#include <stdio.h>//指的是双向循环链表中的结点有效数据类型，用户可以根据需要进行修改
typedef int  DataType_t;//构造双向循环链表的结点,链表中所有结点的数据类型应该是相同的
typedef struct DoubleLinkedList
{DataType_t  		     data; //结点的数据域struct DoubleLinkedList	*prev; //直接前驱的指针域struct DoubleLinkedList	*next; //直接后继的指针域}DoubleLList_t;//创建一个空双向循环链表，空链表应该有一个头结点，对链表进行初始化
DoubleLList_t * DoubleCirLList_Create(void)
{//1.创建一个头结点并对头结点申请内存DoubleLList_t *Head = (DoubleLList_t *)calloc(1,sizeof(DoubleLList_t));if (NULL == Head){perror("Calloc memory for Head is Failed");exit(-1);}//2.对头结点进行初始化，头结点是不存储数据域，指针域指向自身即可，体现“循环”Head->prev = Head;Head->next = Head;//3.把头结点的地址返回即可return Head;
}//创建新的结点，并对新结点进行初始化（数据域 + 指针域）
DoubleLList_t * DoubleCirLList_NewNode(DataType_t data)
{//1.创建一个新结点并对新结点申请内存DoubleLList_t *New = (DoubleLList_t *)calloc(1,sizeof(DoubleLList_t));if (NULL == New){perror("Calloc memory for NewNode is Failed");return NULL;}//2.对新结点的数据域和指针域（2个）进行初始化,指针域指向结点自身，体现“循环”New->data = data;New->prev = New;New->next = New;return New;
}//双向循环链表头插
bool  insertCirDoublyLinList(DoubleLList_t*Head, DoubleLList_t*New)
{DoubleLList_t* Phead;Phead=Head->next;if (Head==Head->next){Phead = New;Head->next=Phead;return true;}Phead->prev->next=New;New->prev=Phead->prev;New->next=Phead;Phead->prev=New;Head->next=New;return true;
}//双向循环链表头删
bool deleteInCircularDoublyLinkedList(DoubleLList_t*Head)
{DoubleLList_t*Phead;Phead=Head->next;if (Head==Head->next){printf("链表为空\n");return true;}if (Phead->next!=Phead){Head->next=Phead->next;Phead->prev->next=Phead->next;Phead->next->prev=Phead->prev; //左值指向右值}else{Head->next=Head;}Phead->next=NULL;Phead->prev=NULL;free(Phead);return true;}