C语言实现单链表

大二学习数据结构和算法啦，因为之前用Java语言实现过，所以理解起来还是比较轻松，就是理解指针与结构体的运用。废话不多说，上代码！

初始化

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

ListNode* InitLink() { //初始化，创建头结点
    ListNode *Head = (ListNode*)malloc(sizeof(ListNode));
    Head->next = NULL;
    return Head;
}

添加

void AddLink(ListNode *Head, int msg) { //添加
    ListNode *Tmp = Head, *New;
    while(Tmp->next != NULL) {
        Tmp = Tmp->next;
    }
    New = (ListNode*)malloc(sizeof(ListNode));
    New->data = msg;
    New->next = NULL;
    Tmp->next = New;
}

删除（可以按值，也可以按位置）

void Delete(ListNode *Head,int data) {//按值删除 
    if(Head->next == NULL) {
        printf("链表无元素可以删除！");
        return;
    }
    
    ListNode *pre = Head; //保存上一个结点 
    ListNode *cur = Head->next;//保存当前结点 
    while(cur != NULL) {
        if(cur->data == data) {
            pre->next = cur->next;//上一个结点的下一个等于当前结点的下一个结点 
            free(cur);//释放结点 
            return;//结束 
        }
        pre = cur;//前一个结点等于当前结点 
        cur = cur->next;//当前结点等于下一个结点 
    }
}

void DeleteMethod(ListNode *head, int element){//按值删除结点
    ListNode *pre = head;
    ListNode *cur = head->next;
    while (cur != NULL){
        if (cur->data == element){
            pre->next = cur->next;
            free(cur);
            return;//结束程序 
        }
        pre = cur;
        cur = cur->next;
    }
}

//index代表删除第几个结点 
void DeleteLink(ListNode *Head,int index){//按下标删除 
    ListNode *Tmp = Head;
    ListNode *Old;
    int mark = 0;
    if(index < 0){
        return;
    }
    while(mark < index-1 && Tmp->next != NULL){
        Old = Tmp;
        Tmp = Tmp->next;
        mark++;
    }
    while(Tmp->next == NULL){
        return; 
    }
    Old = Tmp->next;
    Tmp->next = Old->next; 
    free(Old);
}

修改（可以按值，也可以按位置）

void UpdataLink(ListNode *head, int oldata, int newdata){//按值修改数据
    ListNode *pre = head;
    ListNode *cur = head->next;
    while (cur != NULL){
        if (cur->data == oldata){
            cur->data = newdata;
            return;//结束程序 
        }
        pre = cur;
        cur = cur->next;
    }
}

void UpLink(ListNode *Head,int index,int element){//按下标修改 
    ListNode *Tmp = Head;
    int mark = 0;
    if(index < 0){
        return;
    }
    while(mark < index - 1 && Tmp->next != NULL){
        Tmp = Tmp->next;
        mark++;
    }    
    while(Tmp->next == NULL){
        return; 
    }
    Tmp->next->data = element; 
}

插入（可以按值，也可以按位置）

void InsetrLink(ListNode *head, int oldata, int newdata){//按值输入之前插入 
    ListNode *New = (ListNode*)malloc(sizeof(ListNode));
    New->data = newdata;
    New->next = NULL;
    ListNode *pre = head;
    ListNode *cur = head->next;
    while (cur != NULL){
        if (cur->data == oldata){
            pre->next = New;
            New->next = cur;
            return;//结束程序 
        }
        pre = cur;
        cur = cur->next;
    }
}
void InsertLink(ListNode *Head,int index,int element){//按下标插入 
    ListNode *Tmp = Head;
    ListNode *New;
    int mark = 0;
    if(index < 0){
        return;
    }
    while(mark < index - 1 && Tmp->next != NULL){
        Tmp = Tmp->next;
        mark++;
    }    
    while(Tmp->next == NULL){
        return; 
    }
    New = (ListNode*)malloc(sizeof(ListNode));
    New->data = element;
    New->next = Tmp->next;
    Tmp->next = New;
}

查询（返回一个结点地址）

//提出查找结点方法，其它方法可以调用 
//在单链表中查找第index个结点 
ListNode* GetNode(ListNode *Head,int index){//查找结点方法 
    int mark = 0;
    ListNode *Tmp = Head;
    while(Tmp->next && mark < index){//Tmp->next为NULL 或者 mark==index结束 
        Tmp = Tmp->next;
        mark++;
    }
    if(index == mark){
        return Tmp;
    }else{
        return NULL;
    }
}

销毁

void DestoryLink(ListNode *Head) { //销毁链表
    ListNode *Tmp;
    while(Head->next){
        Tmp = Head->next;
        Head->next = Tmp->next;
        free(Tmp);
    }
    free(Head);//头都删掉 
}

显示

void Display(ListNode *Head) {//显示
    ListNode *Tmp = Head->next;
    while(Tmp != NULL) {
        printf("%d ",Tmp->data);
        Tmp = Tmp->next;
    }
}

甩上完整代码

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

//Upon开发————2019.9.26 
typedef struct Node {
    int data;
    struct Node *next;
} ListNode; 

ListNode* InitLink() { //初始化，创建头结点
    ListNode *Head = (ListNode*)malloc(sizeof(ListNode));
    Head->next = NULL;
    return Head;
}

void AddLink(ListNode *Head, int msg) { //添加
    ListNode *Tmp = Head, *New;
    while(Tmp->next != NULL) {
        Tmp = Tmp->next;
    }
    New = (ListNode*)malloc(sizeof(ListNode));
    New->data = msg;
    New->next = NULL;
    Tmp->next = New;
}

void Delete(ListNode *Head,int data) {//按值删除 
    if(Head->next == NULL) {
        printf("链表无元素可以删除！");
        return;
    }
    
    ListNode *pre = Head; //保存上一个结点 
    ListNode *cur = Head->next;//保存当前结点 
    while(cur != NULL) {
        if(cur->data == data) {
            pre->next = cur->next;//上一个结点的下一个等于当前结点的下一个结点 
            free(cur);//释放结点 
            return;//结束 
        }
        pre = cur;//前一个结点等于当前结点 
        cur = cur->next;//当前结点等于下一个结点 
    }
}

void DeleteMethod(ListNode *head, int element){//按值删除结点
    ListNode *pre = head;
    ListNode *cur = head->next;
    while (cur != NULL){
        if (cur->data == element){
            pre->next = cur->next;
            free(cur);
            return;//结束程序 
        }
        pre = cur;
        cur = cur->next;
    }
}
void InsetrLink(ListNode *head, int oldata, int newdata){//按值输入之前插入 
    ListNode *New = (ListNode*)malloc(sizeof(ListNode));
    New->data = newdata;
    New->next = NULL;
    ListNode *pre = head;
    ListNode *cur = head->next;
    while (cur != NULL){
        if (cur->data == oldata){
            pre->next = New;
            New->next = cur;
            return;//结束程序 
        }
        pre = cur;
        cur = cur->next;
    }
}

void UpdataLink(ListNode *head, int oldata, int newdata){//修改数据
    ListNode *pre = head;
    ListNode *cur = head->next;
    while (cur != NULL){
        if (cur->data == oldata){
            cur->data = newdata;
            return;//结束程序 
        }
        pre = cur;
        cur = cur->next;
    }
}
void InsertLink(ListNode *Head,int index,int element){//按下标插入 
    ListNode *Tmp = Head;
    ListNode *New;
    int mark = 0;
    if(index < 0){
        return;
    }
    while(mark < index - 1 && Tmp->next != NULL){
        Tmp = Tmp->next;
        mark++;
    }    
    while(Tmp->next == NULL){
        return; 
    }
    New = (ListNode*)malloc(sizeof(ListNode));
    New->data = element;
    New->next = Tmp->next;
    Tmp->next = New;
}
void UpLink(ListNode *Head,int index,int element){//按下标修改 
    ListNode *Tmp = Head;
    int mark = 0;
    if(index < 0){
        return;
    }
    while(mark < index - 1 && Tmp->next != NULL){
        Tmp = Tmp->next;
        mark++;
    }    
    while(Tmp->next == NULL){
        return; 
    }
    Tmp->next->data = element; 
}
//index代表删除第几个结点 
void DeleteLink(ListNode *Head,int index){//按下标删除 
    ListNode *Tmp = Head;
    ListNode *Old;
    int mark = 0;
    if(index < 0){
        return;
    }
    while(mark < index-1 && Tmp->next != NULL){
        Old = Tmp;
        Tmp = Tmp->next;
        mark++;
    }
    while(Tmp->next == NULL){
        return; 
    }
    Old = Tmp->next;
    Tmp->next = Old->next; 
    free(Old);
}
//提出查找结点方法，其它方法可以调用 
//在单链表中查找第index个结点 
ListNode* GetNode(ListNode *Head,int index){//查找结点方法 
    int mark = 0;
    ListNode *Tmp = Head;
    while(Tmp->next && mark < index){//Tmp->next为NULL 或者 mark==index结束 
        Tmp = Tmp->next;
        mark++;
    }
    if(index == mark){
        return Tmp;
    }else{
        return NULL;
    }
}
void InsertList(ListNode *Head,int data,int index){//按下标插入 
    ListNode *Tmp = GetNode(Head,index - 1),*New;
    if(Tmp == NULL){
        return;
    }
    New = (ListNode*)malloc(sizeof(ListNode));
    New->data = data;
    New->next = Tmp->next;
    Tmp->next = New;
}
void DeleteList(ListNode *Head,int index){//按下标删除 
    ListNode *Tmp = GetNode(Head,index - 1),*New;
    if(Tmp == NULL || Tmp->next == NULL){
        return;
    }
    New = Tmp->next;
    Tmp->next = New->next;
    free(New);
}
void Display(ListNode *Head) {//显示
    ListNode *Tmp = Head->next;
    while(Tmp != NULL) {
        printf("%d ",Tmp->data);
        Tmp = Tmp->next;
    }
}

void DestoryLink(ListNode *Head) { //销毁链表
    ListNode *Tmp;
    while(Head->next){
        Tmp = Head->next;
        Head->next = Tmp->next;
        free(Tmp);
    }
    free(Head);//头都删掉 
}

int main() {
    ListNode *Head = InitLink();
    AddLink(Head,1);
    AddLink(Head,2);
    AddLink(Head,3);
    AddLink(Head,4);
    AddLink(Head,5);

    UpdataLink(Head,5,4);
    Display(Head);
    return 0;
}