数据结构的练习day2(未完待续)
数据结构线性结构之单向循环链表的基本操作
/********************************************************************************************************
*
*
* 设计单向循环链表的接口
*
*
*
* Copyright (c) 2023-2024 [email protected] All right Reserved
* ******************************************************************************************************/
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.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 CircularLinkedList *next; // 结点的指针域
} CircLList_t;
// 遍历链表
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;
}
// 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
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;
}
// 创建新的结点，并对新结点进行初始化（数据域 + 指针域）
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;
}
// 头插
bool CircLList_HeadInsert(CircLList_t *Head, DataType_t data)
{
if (Head == NULL)
{
printf("链表为空!\n");
return false;
}
// 创建一个指针代替Head
CircLList_t *phead = Head;
// 新建一个结点
CircLList_t *newNode = CircLList_NewNode(data);
// 让新建的结点指向原来的首结点
newNode->next = phead->next;
// 让头结点指向新建的结点
phead->next = newNode;
return true;
}
// 尾插
bool CircLList_TailInsert(CircLList_t *Head, DataType_t data)
{
if (Head == NULL)
{
printf("链表为空!\n");
return false;
}
// 创建一个指针代替Head
CircLList_t *phead = Head->next;
// 新建一个结点
CircLList_t *newNode = CircLList_NewNode(data);
while (phead->next != Head)
{
phead = phead->next;
if (phead->next == Head->next)
{
break;
}
}
// 尾结点指向新结点
phead->next = newNode;
// 新结点指向首结点
newNode->next = Head->next;
return true;
}
// 指定位置插入(后插)
bool CircLList_DestInsert(CircLList_t *Head, DataType_t destval, DataType_t data)
{
if (Head == NULL)
{
printf("链表为空!\n");
return false;
}
// 创建一个指针代替Head
CircLList_t *phead = Head;
// 新建一个结点
CircLList_t *newNode = CircLList_NewNode(data);
while (phead)
{
// 找到目标结点的上前结点
if (phead->next->data == destval)
{
break;
}
phead = phead->next;
}
newNode->next = phead->next;
phead->next = newNode;
}
// 头删
bool CircLList_HeadDel(CircLList_t *Head)
{
// 对单向循环链表的首结点的地址进行备份
CircLList_t *Phead = Head->next;
while (Phead->next != Head)
{
if (Phead->next == Head->next)
{
break;
}
Phead = Phead->next;
}
Phead->next = Head->next->next;
Phead = Head->next;
Head->next = Head->next->next;
Phead->next = NULL;
free(Phead);
return true;
}
// 尾删
bool CircLList_TailDel(CircLList_t *Head)
{
// 对单向循环链表的首结点的地址进行备份
CircLList_t *phead = Head->next;
// 找到尾结点的前一个结点
while (phead->next->next != Head)
{
if (phead->next->next == Head->next)
{
break;
}
phead = phead->next;
}
phead->next->next = NULL;
free(phead->next);
phead->next = Head->next;
return true;
}
// 指定数据的结点删除(后删)
bool CircLList_DestDes(CircLList_t *Head, DataType_t destval)
{
// 对单向循环链表的首结点的地址进行备份
CircLList_t *phead = Head->next;
// 前结点
CircLList_t *preNode = Head;
// 要删除的结点
CircLList_t *delNode = Head->next;
while (phead->next != Head)
{
if (delNode->data == destval)
{
break;
}
preNode = delNode;
delNode = delNode->next;
}
preNode->next = delNode->next;
delNode->next = NULL;
free(delNode);
return true;
}
int main(int argc, char const *argv[])
{
CircLList_t *Head = CircLList_Create();
CircLList_HeadInsert(Head, 40);
CircLList_HeadInsert(Head, 30);
CircLList_HeadInsert(Head, 20);
CircLList_HeadInsert(Head, 10);
CircLList_TailInsert(Head, 50);
CircLList_DestInsert(Head, 30, 15);
CircLList_HeadDel(Head);
CircLList_Print(Head);
CircLList_TailDel(Head);
CircLList_DestDes(Head, 20);
CircLList_Print(Head);
return 0;
}