单链表的简单操作

单链表是C语言，c++和数据结构中的很重要的一个部分，也有很多实现它的方法，这些算法代码的实现都大同小异，我在这里就用c语言和c++两种不同的方法实现一下链表的基本操作。下面是c++和C语言的两种链表结构的定义

c++方式

#include <stdio.h>#include <stdlib.h>#include <assert.h>typedef  int DataType;typedef struct SListNode{DataType data;           //数据struct SListNode* next;  //指向下一个节点的指针}SListNode;

C语言方式

typedef int DataType;typedef struct LinkNode{DataType data;struct LinkNode* next;}LinkNode,*pLinkNode;typedef struct LinkList{LinkNode* pHead;}LinkList,*pLinkList;

c++中有一个该鸟叫做引用&，就是C语言中取地址的那个符号，在这里既然提到了就把C语言和c++中的引用和指针粗浅的提一下

引用：给已经存在的对象起一个别名
类型 &引用变量名 = 已定义过的变量名

引用的特点：

1.可以引用一个对象即一个变量可以有多个别名
2.引用必须初始化  int a = 1; int r& = a;
3.引用只能在初始化的时候引用一次，不能改变为再引用其他的变量
不要返回一个临时变量，局部变量的引用
引用和指针的区别：
1.引用只能在定义时初始化一次，之后不能改变指向其他变量，指针值可变
2.引用必须指向有效的变量，指针可以为空
3.sizeof指针对象和引用对象的意义不一样，sizeof引用得到的是所指向变量的大小，
  而sizeof指针是指向对象地址的大小
4.指针和引用自加（++）自减（--）意义不一样
5.相对而言，引用比指针更安全，指针比引用更灵活，危险系数也更高，检查指针是否为空，
指针所指地址释放后最好置为0，否则存在野指针（垂悬指针）（悬空指针）的问题

所以在c++实现链表中采用引用传值的方法更安全高效

c++实现链表的基本操作

void print(slistnode* head){slistnode* cur = head;while (cur!= null){printf("%d->", cur->data);cur = cur->next;}printf("null");printf("\n");}slistnode* buynode(datatype x){slistnode* temp;temp = (slistnode*)malloc(sizeof(slistnode));temp->data = x;temp->next = null;return temp;}void destoryslist(slistnode* & phead){slistnode* cur = phead;while (cur){slistnode* temp = cur;cur = cur->next;free(temp);temp = null;}}void pushback(slistnode* & phead, datatype x){//1.空//2.不空if (phead == null){phead = buynode(x);}else {slistnode* tail = phead;while (tail->next != null){tail = tail->next;}tail->next = buynode(x);}}void popback(slistnode* & phead){//1.空//2.一个节点//3.多节点if (phead == null){printf("the slist is empty\n");return;}else if (phead->next == null){free(phead);phead = null;}else{slistnode* tail = phead;slistnode* prev = null;while (tail->next != null){prev = tail;tail = tail->next;}free(tail);prev->next = null;}}void pushfront(slistnode* & phead, datatype x){//1.空//2.不空if (phead == null){phead = buynode(x);}else if (phead != null){slistnode* cur = buynode(x);cur->next = phead;phead = cur;}}void popfront(slistnode* & phead){if (phead == null){return;}else if (phead->next == null){free(phead);phead = null;}else if (phead != null){slistnode* cur = phead;phead = phead->next;free(cur);cur = null;}}slistnode* find(slistnode* phead, datatype x){slistnode* cur = phead;while (cur){if (cur->data == x){return cur;}cur = cur->next;}return null;}void insert(slistnode* pos, datatype x){assert(pos);slistnode* temp = buynode(x);temp->next = pos->next;pos->next = temp;}void erase(slistnode* phead,slistnode* pos){assert(pos);assert(phead);if (phead == pos){phead = phead->next;free(pos);pos = null;}slistnode* prev = phead;while (prev){if (prev->next == pos){prev->next = pos->next;free(pos);pos = null;break;}prev = prev->next;}}

C语言实现链表的基本操作

void InitLinkList(pLinkList list){assert(list);list->pHead = NULL;}void Destory(pLinkList list)//销毁链表{pLinkNode cur = NULL;assert(list);if (list->pHead == NULL){return;}cur = list->pHead;while (cur){pLinkNode del = cur;cur = cur->next;free(del);del = NULL;}}pLinkNode BuyNode(DataType x)//构造节点{pLinkNode newNode =(pLinkNode) malloc(sizeof(LinkNode));if (NULL == newNode){printf("out of memory\n");return NULL;}newNode->next = NULL;newNode->data = x;return newNode;}void PrintList(pLinkList list)//show打印{pLinkNode cur = NULL;assert(list);cur = list->pHead;while (cur){printf("%d->", cur->data);cur = cur->next;}printf("NULL\n");}void PushBack(pLinkList list, DataType x)//尾插{pLinkNode cur = NULL;assert(list);cur = list->pHead;pLinkNode newNode = BuyNode(x);if (list->pHead == NULL){list->pHead = newNode;}else{while (cur->next != NULL){cur = cur->next;}cur->next = newNode;}}void PopBack(pLinkList list)//尾删{pLinkNode cur = NULL;pLinkNode prev = NULL;assert(list);cur = list->pHead;prev = NULL;if (cur == NULL){printf("NULL");}else if (cur->next == NULL){free(list->pHead);list->pHead = NULL;}else{while (cur->next != NULL){prev = cur;cur= cur->next;}free(cur);cur = NULL;prev->next = NULL;}}void PushFront(pLinkList list, DataType x)//前插{pLinkNode cur = NULL;assert(list);cur = BuyNode(x);cur->next = list->pHead;list->pHead = cur;}void PopFront(pLinkList list)//尾删{pLinkNode del = NULL;assert(list);del = list->pHead;list->pHead = list->pHead->next;free(del);del = NULL;}//void DestoryList(pLinkList list);LinkNode* Find(pLinkList list, DataType x)//寻找节点{pLinkNode cur = NULL;assert(list);cur = list->pHead;while (cur->next != NULL){if (cur->data == x){return cur;}cur = cur->next;}return NULL;}void Insert(pLinkList list,LinkNode* pos, DataType x)//插入节点{pLinkNode cur = NULL;assert(list);//assert(pos);if (pos == NULL){printf("没找到\n");return;}cur = BuyNode(x);cur->next = pos->next;pos->next = cur;}void Erase(pLinkList list, LinkNode* pos)//删除pos节点{pLinkNode del = NULL;assert(list);if (pos == NULL){printf("无此节点\n");return;}//assert(pos);del = pos->next;del->next = del->next;free(del);del = NULL;}