C语言链表各种操作

链表也就是线性链
单向链表的结构体指针

typedef struct linknode
{
    datatype data;                      
    struct linknode *next;
}Linknode;

data	next

链表插入：

1.插入指针p之后
① s->next = p->next;
②p->next = s;

2.在指针p之前插入

q = head;
while(q->next != p)
	q = q->next;
s->next = q->next;
q->next = s;

链表删除：

q->next = p->next;
delete p;

建立链接②的同时链接①将自动断开

代码

#include
typedef struct linknode
{
    char data;                      //数据是字符型数据
    struct linknode *next;
}Linknode;
Linknode *head;
int n;      //n为线性表长度
//建立线性表
void create_link()
{
    n = 0;
    Linknode *p,*s;
    char x;
    int z = 1;
    head = new Linknode;    //C语言中用head = malloc(sizeof(Linknode))
    p = head;
    printf("\n\t\t请逐个输入结点,以'0'为结束标记！\n");
    while(z)
    {
        scanf("%c",&x);
        getchar();
        if(x != '0')
        {
            s = new Linknode;
            n++;
            s->data = x;
            p->next = s;
            s->next = NULL;
            p = s;
        }
        else
            z = 0;
    }
}
//插入结点操作
void insert_list(int i,char x)
{
    Linknode *s,*p;
    p = head;
    int j = 0;
    while(p != NULL&&jnext;    //指针后移
    }
    if(p != NULL)
    {
        s = new Linknode;
        s->data = x;        //插入结点
        s->next = p->next;      //修改指针
        p->next = s;
        n++;                //表长增加
        printf("\n\t\t结点插入成功！\n");
    }
    else
        printf("\n\t\t线性表为空或者插入位置超出线性表长度！\n");
}
//删除结点操作
void delete_list(char x)
{
    Linknode *q,*p;
    if(head == NULL)
    {
        printf("\n\t\t线性表下溢！\n");
        return;
    }
    if(head->next == NULL)
    {
        printf("\n\t\t线性表为空，无法删除结点！\n");
        return;
    }
    q = head;
    p = head->next;
    while(p != NULL&&p->data != x)
    {
        q = p;
        p = p->next;
    }
    if(p != NULL)
    {
        q->next = p->next;
        delete p;
        n--;
        printf("\n\t\t结点%c已经被删除！\n",x);
    }
    else
        printf("\n\t\t并未找到该结点！\n");
}
//显示线性表
void show()
{
    Linknode *p;
    p = head;
    printf("\n\t\t线性表如下：");
    if(head->next == NULL||p == NULL)
        printf("\n\t\t线性表为空!");
    else
    {
        printf("\n");
        while(p->next != NULL)
        {
            printf("\t%c\n",p->next->data);
            p = p->next;
        }
    }
}
//查找线性表
void search_list(char x)
{
    Linknode *p;
    int i = 1;
    if(head->next == NULL)
    {
        printf("\n\t\t线性表下溢!\n");
        return;
    }
    if(head->next == NULL)
    {
        printf("\n\t\t线性表为空，没有任何结点！\n");
        return;
    }
    p = head->next;
    while(p->data != x&&p != NULL)
    {
        p = p->next;
        i++;
    }
    if(p != NULL)
        printf("\n\t\t%c在线性表的第%d个结点！",x,i);
    else
        printf("\n\t\t并未找到值为%c的结点！",x);
}
void main()
{
    head = NULL;
    int choice,i,j = 1;
    char x;
    while(j)
    {
        printf("\n\t\t***************************************************");
        printf("\n\t\t*                 线性表子系统                    *");
        printf("\n\t\t***************************************************");
        printf("\n\t\t*                 1------建  表                   *");
        printf("\n\t\t*                 2------插  入                   *");
        printf("\n\t\t*                 3------删  除                   *");
        printf("\n\t\t*                 4------显  示                   *");
        printf("\n\t\t*                 5------查  找                   *");
        printf("\n\t\t*                 6------求表长                   *");
        printf("\n\t\t*                 0------返  回                   *");
        printf("\n\t\t***************************************************");
        printf("\n\t\t请选择菜单号：");
        scanf("%d",&choice);
        getchar();
        switch(choice)
        {
            case 1:
                create_link();
                break;
            case 2:
                {
                    printf("\n\t\t请输入要插入的位置：");
                    scanf("%d",&i);
                    printf("\n\t\t请输入要插入的元素：");
                    getchar();
                    scanf("%c",&x);
                    insert_list(i,x);
                    break;
                }
            case 3:
                {
                    printf("\n\t\t请输入要删除的数据：");
                    scanf("%c",&x);
                    delete_list(x);
                    break;
                }
            case 4:
                {
                    if(head == NULL)
                        printf("\n\t\t请先建立线性表！");
                    else
                        show();
                    break;
                }
            case 5:
                {
                    printf("\n\t\t请输入需要查找的数据：");
                    scanf("%c",&x);
                    search_list(x);
                    break;
                }
            case 6:
                printf("\n\t\t线性表长度为：%d",n);
                break;
            case 0:
                j = 0;
                break;
            default:
                j = 0;
                printf("\n\t\t输入错误！请重新输入！");
                break;
        }
    }
}