#include<stdio.h>
#include<stdlib.h>
#include<string.h>
typedef struct student
{
    float stunum;        
    char name[20];  
    float examscore;  
    float labscore;
    float totalmark;  
    struct student * next;  
} stu ;
int len = sizeof(stu);
//定义全局变量.m,t,s[20]用于交换变量 
int i=0;
float t=0,m=0;
char s[20];
stu *p; 


struct student* sort_s(struct student *head)   //排序
{
    if(NULL == head)    //若链表为空则不用排序
    {
        return NULL;
    }
    if(NULL == head->next)  //若链表中只有一个数，则不用比较
    {
        printf("min is head\n");
        return head;
    }
    struct student *min_pre = NULL;
    struct student *min = head;
    struct student *tmp = head;
    struct student *new_list = NULL;   
    struct student *tail_sort = NULL;
    while(head)
    {
        min = head;
        tmp = head;
        while(tmp->next)
        {
            if(min->totalmark > tmp->next->totalmark)
            {
                min = tmp->next;
                min_pre = tmp;
            }
            tmp = tmp->next;
        }
        if(min == head)
        {
            head = head->next;
        }
        else
        {
            min_pre->next = min->next;
            min->next = NULL;
        }
        if(NULL == new_list)    //按照尾插将最小的数组成新的链表
        {
            tail_sort = min;
            new_list = tail_sort;
        }
        else
        {
            tail_sort->next = min;
            tail_sort = min;
        }
    }
    return new_list;
}

stu *create(int n)//n是学生人数
{  
    stu *head,*p1,*p2;
    printf("依次输入学生 学号 姓名 考试成绩 实验成绩\n");
    for(i=0;i<n;i++)//建立链表 
    {
        p1=(stu *)malloc(len);
        if(i==0)
        {
            head=p2=p1;//开始head p1 p2都指向新节点 
            scanf("%f %s %f %f",&p1->stunum,p1->name,&p1->examscore,&p1->labscore);
            p1->next=NULL;
        }
        else
        {
            p2->next=p1;
            p2=p1;//先将末尾节点指向新节点，在将p2指向新节点 
            scanf("%f %s %f %f",&p1->stunum,p1->name,&p1->examscore,&p1->labscore);
            p1->next=NULL;
        } 
    }

    p = head;
    for(i=0;i<n && p!=NULL;i++)//计算学生总评成绩 
    {
        p->totalmark=0.6*p->examscore+0.4*p->labscore; 
        p = p->next;
    }
    head = sort_s(head);
    return head; //返回头指针 
}
int main()
{
    int n;
    stu* ps;
    printf("输入学生人数:\n");
    scanf("%d",&n);//输入学生人数
    p=create(n); //p 赋值链表头指针 
    ps = p; //用ps，否则链表头就丢失了
    for(i=0;i<n && ps!=NULL;i++)
    {
        printf("stunum:%f name:%s examscore:%f labscore:%f totalmark:%f\n",ps->stunum,ps->name,ps->examscore,ps->labscore,ps->totalmark);
        ps = ps->next;
    }
    return 0;
}