单向循环链表

单向循环链表

#include <stddef.h>
#include <stdlib.h>
#include <stdio.h>
#include <stdbool.h>

typedef int DataType_t;

// 构造链表的结点，链表中所有结点的数据类型是相同的
typedef struct CirLinkedList
{
    DataType_t data;        // 节点的数据域
    struct CirLinkedList *next; // 节点的指针域
} CirLiList_t;

// 创建一个空单向循环链表，空链表应该有一个头节点，对链表进行初始化
CirLiList_t *CirLiList_Creat(void)
{
    // 1. 创建一个头结点，为头节点申请内存
    CirLiList_t *Head = (CirLiList_t *)calloc(1, sizeof(CirLiList_t));
    if (NULL == Head)
    {
        perror("Calloc memory for Head is failed");
        return NULL;
    }
    // 2. 对头节点进行初始化，头节点不存储有效内容，指针域指向自身形成循环
    Head->next = Head;
    // 3. 把头结点的地址返回即可
    return Head;
}

// 创建链表的新的节点并对链表进行初始化
CirLiList_t *CirLiList_NewNode(DataType_t data)
{
    // 1. 创建一个新结点，为新节点申请内存
    CirLiList_t *New = (CirLiList_t *)calloc(1, sizeof(CirLiList_t));
    if (NULL == New)
    {
        perror("Calloc memory for NewNode is failed");
        return NULL;
    }
    // 2. 对新节点进行初始化
    New->data = data;
    New->next = NULL;
    return New;
}

// 将新的节点插入到链表首节点//头插
bool CirLiList_HeadInsert(CirLiList_t *Head, DataType_t data)
{
    // 1. 创建新节点并对新节点进行初始化
    CirLiList_t *New = CirLiList_NewNode(data);
    if (NULL == New)
    {
        perror("can not insert new node\n");
        return false;
    }
    // 2. 将新节点插入到链表头部
    New->next = Head->next;
    Head->next = New;
    return true;
}

// 将新的节点插入到链表尾节点//尾插
bool CirLiList_TailInsert(CirLiList_t *Head, DataType_t data)
{
    // 1. 创建新节点并对新节点进行初始化
    CirLiList_t *New = CirLiList_NewNode(data);
    if (NULL == New)
    {
        perror("can not insert new node\n");
        return false;
    }
    // 2. 找到链表的尾节点
    CirLiList_t *Phead = Head;
    while (Phead->next != Head)
    {
        Phead = Phead->next;
    }
    // 3. 将新节点插入到链表尾部
    Phead->next = New;
    New->next = Head;
    return true;
}

// 将新的节点插入到链表指定节点//指定插
bool CirLiList_DestInsert(CirLiList_t *Head, DataType_t dest, DataType_t data)
{
    // 1. 创建新节点并对新节点进行初始化
    CirLiList_t *New = CirLiList_NewNode(data);
    if (NULL == New)
    {
        perror("can not insert new node\n");
        return false;
    }
    // 2. 找到指定节点的前一个节点
    CirLiList_t *Phead = Head;
    while (Phead->next != Head && Phead->next->data != dest)
    {
        Phead = Phead->next;
    }
    if (Phead->next == Head)
    {
        printf("data is not found\n");
        return false;
    }
    // 3. 将新节点插入到指定节点之后
    New->next = Phead->next;
    Phead->next = New;
    return true;
}

// 遍历
void CirLiList_Print(CirLiList_t *Head)
{
    // 对链表的头节点的地址进行备份
    CirLiList_t *Phead = Head->next;
    while (Phead != Head)
    {
        // 输出当前节点的数据域
        printf("data = %d\n", Phead->data);
        printf("data = %x\n", Phead->next);
        Phead = Phead->next;
    }
}

// 删除首节点
bool CirLiList_HeadDel(CirLiList_t *Head)
{
    if (Head == NULL || Head->next == Head)
    {
        perror("The LiList is empty");
        return false;
    }
    CirLiList_t *DelNode = Head->next;
    Head->next = DelNode->next;
    free(DelNode);
    return true;
}

// 删除尾节点
bool CirLiList_TailDel(CirLiList_t *Head)
{
    if (Head == NULL || Head->next == Head)
    {
        perror("The LiList is empty");
        return false;
    }
    CirLiList_t *Phead = Head;
    while (Phead->next->next != Head)
    {
        Phead = Phead->next;
    }
    CirLiList_t *DelNode = Phead->next;
    Phead->next = Head;
    free(DelNode);
    return true;
}

// 删除指定节点
bool CirLiList_DestDel(CirLiList_t *Head, DataType_t dest)
{
    if (Head == NULL || Head->next == Head)
    {
        perror("The LiList is empty");
        return false;
    }
    CirLiList_t *Phead = Head;
    while (Phead->next != Head && Phead->next->data != dest)
    {
        Phead = Phead->next;
    }
    if (Phead->next == Head)
    {
        printf("data is not found\n");
        return false;
    }
    CirLiList_t *DelNode = Phead->next;
    Phead->next = DelNode->next;
    free(DelNode);
    return true;
}

int main(int argc, char const *argv[])
{
    CirLiList_t *Head = CirLiList_Creat();
    CirLiList_TailInsert(Head, 1);
    CirLiList_TailInsert(Head, 2);
    CirLiList_TailInsert(Head, 3);
    CirLiList_TailInsert(Head, 4);
    CirLiList_Print(Head);
    printf("\n");
    CirLiList_HeadInsert(Head, 6);
    // 可以在此处调用其他操作函数进行测试
    CirLiList_Print(Head);
    printf("\n");
    CirLiList_HeadDel(Head);
    CirLiList_Print(Head);
    printf("\n");
    CirLiList_TailDel(Head);
    CirLiList_Print(Head);
    printf("Head = %x\n",Head);
    return 0;
}  

运行结果