#include<stdio.h>
#include<malloc.h>
#include<string.h>
typedef struct Student
{
 int no;
 char name[10];
 float score[3];  //three scores
 float average;  //average score
 struct Student *next;
}Student;

void Initial(Student *p)
{
 p=(Student*)malloc(sizeof(Student));//the head of the linklist
 p->next=NULL;
}
void Input(Student *p)
{
 Student *stu=(Student*)malloc(sizeof(Student));
 printf("学号："); scanf("%d",&stu->no);
 printf("姓名："); scanf("%s",stu->name);
 printf("成绩1："); scanf("%f",&stu->score[0]);
 printf("成绩2："); scanf("%f",&stu->score[1]);
 printf("成绩3："); scanf("%f",&stu->score[2]);
 stu->average=(stu->score[0]+stu->score[1]+stu->score[2])/3;
 stu->next=NULL;
 Student *ps=(Student*)malloc(sizeof(Student));
 ps=p;
 while(ps->next)
  ps=ps->next;
 ps->next=stu;
 //free(ps);
}

void Output(Student *p)
{
 Student *ps=(Student*)malloc(sizeof(Student));
 ps=p->next;
 printf("学号\t姓名\t成绩1\t成绩2\t成绩3\t平均分\n");
 while(ps!=NULL)
 {
  printf("%d\t",ps->no);
  printf("%s\t",ps->name);
  printf("%.1f\t",ps->score[0]);
  printf("%.1f\t",ps->score[1]);
  printf("%.1f\t",ps->score[2]);
  printf("%.1f\t\n",ps->average);
  ps=ps->next;  
 }
 free(ps);
}
void Find(Student *p)
{
 Student *ps=(Student*)malloc(sizeof(Student));
 ps=p->next;
 char name[10];
 printf("输入要查询的学生姓名:");
 scanf("%s",name);
 while(strcmp(ps->name,name)!=0) //相同时为0
  ps=ps->next;  
 
 printf("学号\t姓名\t成绩1\t成绩2\t成绩3\t平均分\n");
 printf("%d\t",ps->no);
 printf("%s\t",ps->name);
 printf("%.1f\t",ps->score[0]);
 printf("%.1f\t",ps->score[1]);
 printf("%.1f\t",ps->score[2]);
 printf("%.1f\t\n",ps->average);
 
}
void swap(Student *p1, Student *p2) //swap two nodes for sorting
{
 Student *temp=(Student*)malloc(sizeof(Student));
 temp->no=p1->no;
 strcpy(temp->name,p1->name);
 temp->score[0]=p1->score[0];
 temp->score[1]=p1->score[1];
 temp->score[2]=p1->score[2];
 temp->average=p1->average;
 
 p1->no=p2->no;
 strcpy(p1->name,p2->name);
 p1->score[0]=p2->score[0];
 p1->score[1]=p2->score[1];
 p1->score[2]=p2->score[2];
 p1->average=p2->average;
 
 p2->no=temp->no;
 strcpy(p2->name,temp->name);
 p2->score[0]=temp->score[0];
 p2->score[1]=temp->score[1];
 p2->score[2]=temp->score[2];
 p2->average=temp->average;

 free(temp);
}
void Sort(Student *p) //sort by average
{
 Student *p1=(Student*)malloc(sizeof(Student));
 Student *p2=(Student*)malloc(sizeof(Student));
 p1=p->next;
 while(p1)
 {
  float avg=p1->average;
  p2=p1->next;
  while(p2)
  {
   if( avg< (p2->average))
   {
    swap(p1,p2);
    avg=p2->average;
   }
   p2=p2->next;
  }
  p1=p1->next;
 }
}
void Insert(Student *p)
{
 printf("按平均分高低插入数据!\n"); 
 Student *stu=(Student*)malloc(sizeof(Student));//the data being inserted
 
 printf("学号："); scanf("%d",&stu->no);
 printf("姓名："); scanf("%s",stu->name);
 printf("成绩1："); scanf("%f",&stu->score[0]);
 printf("成绩2："); scanf("%f",&stu->score[1]);
 printf("成绩3："); scanf("%f",&stu->score[2]);
 stu->average=(stu->score[0]+stu->score[1]+stu->score[2])/3;
 stu->next=NULL;
 
 Student *p1=(Student*)malloc(sizeof(Student));//temp
 p1=p;
 while(p1->next && ((p1->next)->average) >(stu->average))
  p1=p1->next;
 //p1=p1->next;
 stu->next=p1->next;
 p1->next=stu;

}
void Menu(Student *p)
{
 int select;
 printf("您好，欢迎使用学生成绩管理系统！\n");
 printf("1:输入学生成绩数据\n2：输出全部学生信息\n3：按姓名查找学生记录\n4：按平均成绩进行排序\n5：按平均成绩高低插入数据\n6:退出\n");
 scanf("%d",&select);
 while(select<=6 && select>0)
 {
  switch(select)
  {
   case 1: Input(p);break;
   case 2: Output(p);break;
   case 3: Find(p);  break;
   case 4: Sort(p); break;
   case 5: Insert(p); break;
   case 6: printf("成功退出，欢迎再次使用！\n"); return ; break;
  }
  printf("1:输入学生成绩数据\n2：输出全部学生信息\n3：按姓名查找学生记录\n4：按平均成绩进行排序\n5：按平均成绩高低插入数据\n6:退出\n");
  scanf("%d",&select);
 }
 
}
int main()
{
 Student *head=(Student*)malloc(sizeof(Student));
 Menu(head);
}