链表的基本操作

#define _CRT_SECURE_NO_WARNINGS
#include "stdlib.h"
#include "stdio.h"
#include "string.h"

typedef struct Node
{
int data;
struct Node *next;
}SLIST;

SLIST *Creat_SList();
int SList_Print(SLIST *pHead);
//在结点数值为x的前面插入y
int SList_NodeInsert(SLIST *pHead, int x, int y);
//删除结点为y的链表结点
int SList_NodeDel(SLIST *pHead, int y);
int SList_Destory(SLIST *pHead);
int SList_revse(SLIST *pHead);

SLIST *Creat_SList()
{
//1 创建头结点并初始化
int data = 0;
SLIST *pHead = NULL, *pM = NULL, *pCur;
pHead = (SLIST *)malloc(sizeof(SLIST));
if (pHead == NULL)
{
return NULL;
}
pHead->data = 0;
pHead->next = NULL;

//2循环创建结点，结点数据域中的数值从键盘输入，
//以-1作为输入结束标志
printf("\nPlease enter the data of node(-1:quit) ");
scanf("%d", &data);

//准备环境 让pCur指向pHead
pCur = pHead;
while (data != -1)
{
//不断的malloc新节点 并且数据域 赋值
pM = (SLIST *)malloc(sizeof(SLIST));
if (pM == NULL)
{
SList_Destory(pHead);
return NULL;
}
pM->data = data;
pM->next = NULL;

//1新节点入链表
pCur->next = pM;

//2 当前结点下移（新结点变成当前结点）
pCur = pM; // (pCur = pCur->next)

printf("\nPlease enter the data of node(-1:quit) ");
scanf("%d", &data);
}
return pHead;
}

int Creat_SList2(SLIST **Head)
{
int ret = 0;
//1 创建头结点并初始化
int data = 0;
SLIST *pHead = NULL, *pM = NULL, *pCur = NULL;
pHead = (SLIST *)malloc(sizeof(SLIST));
if (pHead == NULL)
{
ret = -1;
printf("func Creat_SList() err:%d", ret);
return ret;
}
pHead->data = 0;
pHead->next = NULL;

//2循环创建结点，结点数据域中的数值从键盘输入，
//以-1作为输入结束标志
printf("\nPlease enter the data of node(-1:quit) ");
scanf("%d", &data);

//准备环境 让pCur指向pHead
pCur = pHead;
while (data != -1)
{
//不断的malloc新节点 并且数据域 赋值
pM = (SLIST *)malloc(sizeof(SLIST));
if (pM == NULL)
{
SList_Destory(pHead);
ret = -2;
printf("func Creat_SList() err:%d malloc err", ret);
return ret;
}
pM->data = data;
pM->next = NULL;

//1新节点入链表
pCur->next = pM;

//2 当前结点下移（新结点变成当前结点）
pCur = pM; // (pCur = pCur->next)

printf("\nPlease enter the data of node(-1:quit) ");
scanf("%d", &data);
}
*Head = pHead;
return ret;
}

int SList_Print(SLIST *pHead)
{
SLIST *p = NULL;

if (pHead == NULL)
{
return -1;
}
//准备环境
p = pHead->next;
printf("\nBegin ");
while (p)
{
printf("%d ", p->data);
p = p->next;
}
printf("End ");
return 0;
}

//在结点数值为x的前面插入y
int SList_NodeInsert(SLIST *pHead, int x, int y)
{
SLIST *pCur = NULL, *pPre = NULL, *pM = NULL;
if (pHead == NULL)
{
return -1;
}
//环境准备
pPre = pHead;
pCur = pHead->next;

//不断的malloc新节点 并且数据域 赋值
pM = (SLIST *)malloc(sizeof(SLIST));
pM->data = y;
pM->next = NULL;

while (pCur)
{
if (pCur->data == x)
{
break;
}
//让pPre下移
pPre = pCur;
//让当前节点下移
pCur = pCur->next;
}

//让新节点链接后继结点
pM->next = pPre->next; //(pCur)
//让前驱结点连接pM
pPre->next = pM;

return 0;
}

//删除结点为y的链表结点
int SList_NodeDel(SLIST *pHead, int y)
{
SLIST *pCur = NULL, *pPre = NULL;
if (pHead == NULL)
{
return -1;
}
//环境准备
pPre = pHead;
pCur = pHead->next;

while (pCur)
{
if (pCur->data == y)
{
break;
}
//让pPre下移
pPre = pCur;
//让当前节点下移
pCur = pCur->next;
}
if (pCur == NULL)
{
printf("没有找到节点 y:%d", y);
return -2;
}
//执行操作
pPre->next = pCur->next;
free(pCur);
return 0;
}

int SList_Destory(SLIST *pHead)
{
//1、删除当前结点前，需要把后继结点位置缓存

SLIST *pTmp = NULL;
SLIST *pCur = pHead;
if (pHead == NULL)
{
return -1;
}

while (pCur)
{
//缓存后继结点位置
pTmp = pCur->next;
//删除当前结点
free(pCur);
//当前结点下移
pCur = pTmp;
}
return 0;
}

int SList_revse(SLIST *pHead)
{

SLIST *p = NULL, *q = NULL, *t = NULL;

if (pHead == NULL)
{
return -1;
}
if (pHead->next == NULL || pHead->next->next == NULL)
{
return 0;
}
//准备环境
p = pHead->next;
q = pHead->next->next;

while (q != NULL)
{
//1、在逆置之前需要做一个缓存
t = q->next;

//2、开始逆置
q->next = p;

//3、让p后移
p = q;
//4、q后移
q = t;
}

//让第一个业务结点赋值null
pHead->next->next = NULL;
//让链表头指向最后一个节点
pHead->next = p;
return 0;
}

void main()
{
int ret = 0;
SLIST *pHead = NULL;
//创建 并打印
pHead = Creat_SList();
ret = SList_Print(pHead);

//插入操作
ret = SList_NodeInsert(pHead, 20, 19);
ret = SList_Print(pHead);

ret = SList_NodeDel(pHead, 19);
ret = SList_Print(pHead);

ret = SList_revse(pHead);
ret = SList_Print(pHead);

ret = SList_Destory(pHead);
system("pause");
}