//实现链表的建立，插入，删除，输出函数
#include<stdio.h>
#include<malloc.h>
#define LEN sizeof(struct Student)
struct Student{
    long num;
    float score;
    struct Student *next;
};
int n;//////////////////////////////////////记录学生数据的个数
void main()
{
    struct Student *create();
    struct Student *del(struct Student *head,long num);
    struct Student *insert(struct Student *head,struct Student *stu);
    void print(struct Student *head);
    struct Student *head,*stu;
    long del_num;
    printf("input records:\n");                      //输入提示
    head = create();                                 //建立链表，返回头指针
    print(head);                                     //输出全部结点
    printf("input the delete number :");             //提示删除
    scanf("%ld",&del_num);                           //输入删除数据
    while(del_num != 0)                              //当输入数据不为零是进行删除操作，对del函数循环调用
    {                 
        head = del(head,del_num);                    //删除链表后，返回头指针
        print(head);                                 //输出全部结点                             
        printf("input the delete number :");   
        scanf("%ld",&del_num);
    }
    printf("\ninput the insert number:  ");          //输入提示
    stu = (struct Student*)malloc(LEN);              //开辟一个崭新的结点
    scanf("%ld,%f",&stu->num ,&stu->score );         //数据输入
    while(stu->num != 0)                             //判断学号是否为零，对insert函数循环调用
    {
        head = insert(head ,stu);                    //返回链表头地址，赋给head
        print(head);
        printf("\ninput the insert number:  ");
        stu = (struct Student*)malloc(LEN);           //开辟一个崭新的结点
        scanf("%ld,%f",&stu->num ,&stu->score );
    }                                

}
//创建链表的函数
struct Student *create()
{
    struct Student *head;
    struct Student *p1,*p2;
    n = 0;
    p1 = p2 = (struct Student*)malloc(LEN); //开辟一个新单元，并使p1,p2指向它
    scanf("%ld,%f",&p1->num, &p1->score );
    head = NULL;
    while(p1->num != 0)
    {
        n = n + 1;
        if(n == 1)head = p1;
        else p2->next = p1;
        p2 = p1;
        p1 = (struct Student*)malloc(LEN);
        scanf("%ld,%f",&p1->num,&p1->score);
    }
    p2->next = NULL;
    return head;
}
//删除结点函数
struct Student *del(struct Student *head,long num)
{
    struct Student *p1,*p2;
    if(head == NULL)             //若是空表
    {
        printf("\nlist null!\n");
        return head;
    }
    p1 = head;
    while(num != p1->num && p1->next != NULL)//p1所指向的不是所找结点且后面还有结点
    {
        p2 = p1;p1 = p1->next ;              //p1后移一个结点
    }
    if(num == p1->num )
    {
        if(p1 == head) head = p1->next ;      //如果要删除的是首结点，就把第二个结点的地址赋予head
        else p2->next = p1->next;             //否则将下一个结点地址赋给前一个结点
        printf("delete:%ld\n",num);
        n=n-1;   
    }
    else
            printf("%d not been found.");     //找不到该结点
    return head;
}
//插入结点函数
struct Student *insert(struct Student *head,struct Student *stu)
{
    struct Student *p0,*p1,*p2;
    p1 = head;
    p0 = stu;                     //p0指向要插入的结点
    if(head == NULL)                  //原来的链表是空表
    {head = p0;p0->next = NULL;}   // 使p0指向的结点作为头结点
    else
    {
        while((p0->num > p1->num) && (p1->next != NULL))//题目要求的是学生按高矮顺序排序 所以高的同学往后移
        {
            p2 = p1;
            p1 = p1->next ;
        }
        if(p0->num < p1->num )
        {
            if(head == p1)head = p0;/////////////////////////??????(为什么没有p0->next=p1)
            else
                p2->next = p0;
                p0->next = p1;
        }
        else
        {
            p1->next = p0;           //插入到最后结点
            p0->next =NULL;
        }
    }
    n=n+1;
    return head;

}
void print(struct Student *head)
{
    struct Student *p;
    printf("\n Now,These %d records are:\n",n);
    p =head ;
    if(head !=NULL)
        do{
            printf("%ld,%5.1f\n",p->num ,p->score );
            p = p->next ;
        }while(p!=NULL);
        
}

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

#define LEN sizeof(struct Student)

struct Student
{
    long num;
    float score;
    struct Student *next;
};

struct Student *insert(struct Student *head);
struct Student *insert_sort(struct Student *head, struct Student stu);
void print(struct Student *head);

void main()
{
    struct Student *head=NULL;
    head = insert(head);
    print(head);
}

struct Student *insert(struct Student *head)
{
    struct Student stu;
    printf("input the insert:\nnumber,score\n");
    while (scanf("%ld,%f",&stu.num,&stu.score)==2 && stu.num>0)
    {
        head = insert_sort(head, stu);
    }
    return head;
}

struct Student *insert_sort(struct Student *head, struct Student stu)
{
    struct Student *p, *q, *s;
    p = head;
    q = NULL;
    s = (struct Student*)malloc(LEN);
    if (s != NULL)
    {
        s->num = stu.num;
        s->score = stu.score;
        s->next = NULL;
        while (p != NULL)
        {
            if (s->num <= p->num)
            {
                s->next = p;
                break;
            }
            q = p;
            p = p->next;
        }
        if (q != NULL)
            q->next = s;
        else
            head = s;
    }
    return head;
}

void print(struct Student *head)
{
    int n=0;
    struct Student *p=head;
    while(p != NULL)
    {
        printf("%ld,%5.1f\n", p->num, p->score);
        p = p->next;
        ++n;
    }
    printf("Now,These %d records\n",n);
}