数据结构3_160805无头单向不循环

单链表优点：动态结构，整个空间可以多个链表共用

不需要预先分配空间

插入删除方便

缺点：指针占用额外的空间，不能随机查找

==============list.h========================

#ifndef LIST_H__
#define LIST_H__
#define SIZE 32
typedef struct _datatype
{
    int id;
    char name[SIZE];
    int math;
    int chinese;

}datatype;
typedef struct node_st{

    datatype data;
    struct node_st *next;
}list;

int list_destroy(list *);

void list_display(list *);

int list_insert(list **, datatype *);

int list_delete(list **);

datatype *list_find(list *,int );
#endif

===========list.c=======================

#include"list.h"
#include<stdlib.h>
#include<string.h>
#include<stdio.h>

void list_display(list *me)
{

   
    list *cur;

    for (cur = me; cur!=NULL; cur = cur->next)
    {
        printf("%d   %s  %d  %d\n",cur->data.id, cur->data.name, cur->data.math, cur->data.chinese);

    }

    return ;
}

int  list_destroy(list *me)
{  

    list * save = NULL;

    while(me)
    {
        save = me->next;
        free(me);
        me = save;
       
    }

    return 0;

}
        
int list_insert(list **me, datatype *data)
{
   

    list *new;
    new = malloc(sizeof(*new));
    if (NULL == new)
        return -1;
    new->data = *data;
    new->next = *me;
    *me = new;
    return 0;

}
             
                
int list_delete(list **me)
{
    if(NULL == *me)
        return -1;
    list *save;
    save = *me;
    *me = (*me)->next;

    free(save);

    return 0;

}
datatype *list_find (list *me, int id)

{      
    list *save;
    for (save = me;save!=NULL;save = save->next)
    {
           if( save->data.id ==id)
           {
            return &save->data;
            }
    }
    return NULL;
}

===============main.c==========================

#include<stdio.h>
#include<string.h>
#include<stdlib.h>
#include"list.h"

int main()
{
    list *list = NULL;

    datatype tmp;

    int i;

    for (i = 0; i <7 ; i++)

    {
        tmp.id = i;
        snprintf(tmp.name, SIZE, "stu%d",i);
        tmp.math = rand()%100;
        tmp.chinese = rand()%100;
        list_insert(&list, &tmp);

    }

    list_display(list);
    list_delete(&list);
    printf("=============\n");
    list_display(list);
    datatype *prt;
    prt = list_find(list,3);
    if(prt==NULL)
        printf("can't find\n");
    else
        printf("find it\n");
    list_destroy(list);
return 0;
   

}