单向循环链表的增删改查

数据结构

单向循环链表

单向循环链表的增删改查

/*************************************************************************************
 *
 *  file name:  1.c
 *  author   : 	lu.ciana.598393@gmail.com
 *  date     :  2024/04/23
 *  function : 	单向循环链表的增删改查
 *  note     :  None
 *  CopyRight (c)   2024    lu.ciana.598393@gmail.com   All Right Reserved
 *
 ************************************************************************************/
#include <stdio.h>
#include <stdbool.h>
#include <stdlib.h>

//指的是单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;
//构造单向循环链表的结点,链表中所有结点的数据类型应该是相同的
typedef struct CircularLinkedList
{
	DataType_t  		 data; //结点的数据域
	struct LinkedList	*next; //结点的指针域

}CircLList_t;

/**
  * @name:		CircLList_Create
  * @brief 		创建一个空单向循环链表，空链表应该有一个头结点，对链表进行初始化
  * @retval 	CircLList_t *
  * @date 		2024/04/23
  */

CircLList_t * CircLList_Create(void)
{
	//1.创建一个头结点并对头结点申请内存
	CircLList_t *Head = (CircLList_t *)calloc(1,sizeof(CircLList_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，体现“循环”思想
	Head->next = Head;

	//3.把头结点的地址返回即可
	return Head;
}
/**
  * @name:		CircLList_NewNode
  * @brief  	创建新的结点，并对新结点进行初始化（数据域 + 指针域）
  * @param  
  				@data
  * @retval 	CircLList_t *
  * @date 		2024/04/23
  */
CircLList_t *CircLList_NewNode(DataType_t data)
{
	//1.创建一个新结点并对新结点申请内存
	CircLList_t *New = (CircLList_t *)calloc(1,sizeof(CircLList_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进行初始化
	New->data = data;
	New->next = NULL;
	return New;
}

/**
  * @name:		CircLList_HeadInsert
  * @brief  	头插
  * @param  
  				@data
  				@Head
  * @retval 	bool
  * @date 		2024/04/23
  */
bool CircLList_HeadInsert(CircLList_t *Head,DataType_t data)
{
	CircLList_t *PHead =Head;
	CircLList_t *New = CircLList_NewNode(data);	
	//如果申请内存失败
	if (NULL == New)
	{
		perror("Calloc memory for NewNode is Failed");
		return false;
	}
	//如果是空链表,直接插入	
	if (Head->next == Head)
	{
		Head->next = New;
		New->next = New;
		return true;
	}
	//遍历获取最后的值
	while(PHead->next)
	{
		PHead = PHead ->next;
		if(PHead->next == Head->next)
			break;
	}

	New->next = Head->next;	
	Head->next = New;
	PHead->next = New;
	return true;
}
/**
  * @name:		CircLList_TailInsert
  * @brief  	尾插
  * @param  
  				@data
  				@Head
  * @retval 	bool
  * @date 		2024/04/23
  */
bool CircLList_TailInsert(CircLList_t *Head,DataType_t data)
{
	CircLList_t *PHead =Head;
	CircLList_t *New = CircLList_NewNode(data);	
	//如果申请内存失败
	if (NULL == New)
	{
		perror("Calloc memory for NewNode is Failed");
		return false;
	}
	//如果是空链表,直接插入
	if (Head->next == Head)
	{
		Head->next = New;
		New->next = New;
		return true;
	}
	//遍历获取最后的值
	while(PHead->next)
	{
		PHead = PHead ->next;
		if(PHead->next == Head->next)
			break;
	}

	PHead->next = New;
	New->next=Head->next;
	return true;
}

/**
  * @name:		CircLList_DestInsert
  * @brief  	指定位置插入
  * @param  
  				@data
  				@Head
  				@destval
  * @retval 	bool
  * @date 		2024/04/23
  */

bool CircLList_DestInsert(CircLList_t *Head,DataType_t destval,DataType_t data)
{
	CircLList_t *PHead =Head;
	CircLList_t *New = CircLList_NewNode(data);	
	//如果申请内存失败
	if (NULL == New)
	{
		perror("Calloc memory for NewNode is Failed");
		return false;
	}
	//如果是空链表,直接插入
	if (Head->next == Head)
	{
		Head->next = New;
		New->next = New;
		return true;
	}
	//遍历获取目标值
	while(PHead->next)
	{
		PHead = PHead ->next;
		if(destval == PHead->data)
			break;
	}
	New->next = PHead->next;
	PHead->next = New;
	return true;
}

/**
  * @name:		CircLList_Print
  * @brief  	遍历链表
  * @param  
  				@Head
  * @retval 	bool
  * @date 		2024/04/23
  */
bool CircLList_Print(CircLList_t *Head)
{
	//对单向循环链表的头结点的地址进行备份
	CircLList_t *Phead = Head;
	
	//判断当前链表是否为空，为空则直接退出
	if (Head->next == Head)
	{
		printf("current linkeflist is empty!\n");
		return false;
	}

	//从首结点开始遍历
	while(Phead->next)
	{
		//把头结点的直接后继作为新的头结点
		Phead = Phead->next;

		//输出头结点的直接后继的数据域
		printf("data = %d\n",Phead->data);

		//判断是否到达尾结点，尾结点的next指针是指向首结点的地址
		if (Phead->next == Head->next)
		{
			break;
		}	
	}
	return true;
}

/**
  * @name:		LList_HeadDel
  * @brief  	头删
  * @param  
  				@Head
  * @retval 	bool
  * @date 		2024/04/23
  */
bool LList_HeadDel(CircLList_t *Head)
{
	//对单向循环链表的头结点的地址进行备份
	CircLList_t *PHead = Head->next;
	CircLList_t *LHead = Head;
	//链表为空
	if (Head == Head->next)
        return false;
	//链表内只有一个节点
	if(Head->next == PHead->next)
	{
		PHead->next = NULL;
		LHead->next = Head;
		free(PHead);
		return true;
	}
	//遍历获得尾结点并使其指向头结点的下下个结点
	while(LHead->next)
	{
		LHead = LHead->next;
		if(LHead->next == PHead)
			break;
	}
	LHead->next = PHead->next;
	Head->next = PHead->next;
	PHead->next = NULL ;
	free(PHead);
    return true;
}


/**
  * @name:		LList_TailDel
  * @brief  	尾删
  * @param  
  				@Head
  * @retval 	bool
  * @date 		2024/04/23
  */
bool LList_TailDel(CircLList_t *Head)
{
	//对单向循环链表的头结点的地址进行备份
	CircLList_t *PHead = Head->next;
	CircLList_t *LHead = Head;
	//链表为空
	if (Head == Head->next)
        return false;
	//遍历获得尾结点及其直接前驱
	while(LHead->next)
	{
		PHead = PHead->next;
		LHead = LHead->next;
		if(PHead->next == Head->next)
			break;
	}
		LHead->next=Head->next;
		PHead->next = NULL;
		free(PHead);
    	return true;
}
/**
  * @name:		CircLList_DestDel
  * @brief  	指定位置删
  * @param  
  				@Head
  				@destval
  * @retval 	bool
  * @date 		2024/04/23
  */
bool CircLList_DestDel(CircLList_t *Head,DataType_t destval)
{
	//对单向循环链表的头结点的地址进行备份
	CircLList_t *PHead = Head->next;
	CircLList_t *LHead = Head;
	//链表为空
	if (Head == Head->next)
        return false;
	
	//遍历获得尾结点及其直接前驱
	while(LHead->next)
	{
		PHead = PHead->next;
		LHead = LHead->next;
		if(destval == PHead->data)
			break;
	}
	LHead->next = PHead->next;
	PHead->next = NULL;
	free(PHead);
    return true;
}

//调用函数测试
int main(int argc, char const *argv[])
{
	CircLList_t * Head=CircLList_Create();
	CircLList_TailInsert(Head,2);
	CircLList_TailInsert(Head,10);
	CircLList_TailInsert(Head,1);	
	CircLList_TailInsert(Head,6);
	CircLList_DestInsert(Head,10,8);
	CircLList_TailInsert(Head,4);
	LList_HeadDel(Head);
	LList_TailDel(Head);
	CircLList_DestDel(Head,1);
	
	CircLList_Print(Head);

}