之前大一写的，一年前的水平
现在学习数据结构，重新拿出来看看
现在学习数据结构，重新拿出来看看
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#include<stdio.h>
#include<malloc.h>
#include<stdlib.h>
#include<conio.h>
#include<ctype.h>
#define Esc 27
#define NULL 0
#define LEN sizeof(struct student)
struct student
{
char class_0[20]; //班级
int num; //学号
char name[20]; //姓名
float c_prog; //c语言程序设计
float eng; //大学英语
float math; //高等数学
float avg; //平均成绩
int order; //名次
struct student *next;
};
int n; //全局变量，统计学生记录的个数
//函数声明
struct student *create();
void Output(struct student *head);
struct student *Delete(struct student *head, int num);
struct student *insert(struct student *head, struct student *stud);
struct student *Lookup(struct student *head, int num);
struct student *Modify(struct student *head, int num);
float Statistic(struct student *p);
struct student *order(struct student *head);
void start();
void goon();
void exit();
//创建链表，输入学生信息
struct student *create()
{
struct student *head;
struct student *pl;
n=0;
pl=(struct student*) malloc(LEN);
printf("\n\n\t请输入学生的信息: \n");
printf("\t输入格式为：(每输入一项回车，以学号为0退出!)\n");
printf("\t请输入学生学号:");
scanf("%d",&pl->num );
printf("\t请输入学生姓名:");
scanf("%s",&pl->name );
printf("\t请输入学生班级:");
scanf("%s",&pl->class_0 );
printf("\n");
printf("\t请输入程序设计成绩:");
scanf("%f",&pl->c_prog );
printf("\t请输入大学英语成绩:");
scanf("%f",&pl->eng );
printf("\t请输入高等数学成绩:");
scanf("%f",&pl->math );
printf("\n");
head=NULL;
while(pl->num !=0)
{
pl->avg =Statistic(pl); //求pl的平均值
head=insert(head,pl); //创建链表
pl=(struct student*)malloc(LEN);
printf("\n\t如果你想结束输入，请输入 0 !\n\n");
printf("\t请输入学号:");
scanf("%d",&pl->num );
if(pl->num ==NULL) //控制是否退出
continue;
printf("\t请输入学生姓名:");
scanf("%s",&pl->name );
printf("\t请输入学生班级:");
scanf("%s",&pl->class_0 );
printf("\n");
printf("\t请输入程序设计成绩:");
scanf("%f",&pl->c_prog );
printf("\t请输入大学英语成绩:");
scanf("%f",&pl->eng );
printf("\t请输入高等数学成绩:");
scanf("%f",&pl->math );
printf("\n");
}
return (head);
}
//输出链表
void Output(struct student *head)
{
struct student *p;
printf("\n\t现在有%d个记录是:\n",n);
p=head;
printf("\n\n\n****************学生成绩信息表****************\n\n");
printf("\n学号\t姓名\t班级\t程序设计 大学英语 高等数学 平均分 学生名次\n");
if(head!=NULL)
do
{
printf("%-10d",p->num );
printf("%-10s",p->name );
printf("%-8s",p->class_0 );
printf("%-8.2f",p->c_prog );
printf("\t%-8.2f",p->eng );
printf("%-8.2f",p->math );
printf("%-8.2f",p->avg );
printf("\t%-3d\n",p->order );
p=p->next ;
} while(p!=NULL);
}
//根据学号来删除学生信息
struct student *Delete(struct student *head, int num)
{
struct student *p1,*p2;
if(head==NULL) //空链表时返回
{
printf("\n\t链表为空!\n");
return(head);
}
p1=head;
while(num!=p1->num &&p1->next!=NULL)
{
p2=p1;
p1=p1->next ;
}
if(num==p1->num ) //链表找到相应的学号
{
if(p1==head)
head=p1->next ;
else //表中和表尾删除
p2->next =p1->next ;
printf("\n\t你删除的学生信息为: \n");
printf("\t学号为：%d\t",p1->num );
printf("\t姓名为：%s\t",p1->name );
printf("\t班级为：%s\t",p1->class_0 );
printf("\n");
printf("\t程序设计成绩为：%.2f\t",p1->c_prog );
printf("\n");
printf("\t\t大学英语成绩为：%.2f\t",p1->eng );
printf("\t\t高等数学成绩为：%.2f\t",p1->math );
printf("\n");
printf("\t\t平均成绩为：%.2f\t",p1->avg );
printf("\t学生名次为：%d\t",p1->order );
printf("\n");
n=n-1;
free(p1);
}
else //找不到学号
printf("\t学号%d没有找到!\n",num);
return(head);
}
//插入学生信息
struct student *insert(struct student *head, struct student *stud)
{
struct student *p0,*p1,*p2;
p1=head;
p0=stud;
if(head==NULL) //空链表时返回
{
head=p0;
p0->next =NULL;
}
else
{
while((p0->avg <p1->avg )&&(p1->next !=NULL))
{
p2=p1;
p1=p1->next;
}
if(p0->avg >=p1->avg )
{
if(p1==head) //链表头插入
{
p0->next =p1;
head->next =p0;
}
else //链表中插入
{
p2->next =p0;
p0->next =p1;
}
}
else //链表尾部插入
{
p1->next =p0;
p0->next =NULL;
}
}
n=n+1;
p0->order=0; //初始化名次
return(head);
}
//根据学生学号来查找学生信息
struct student *Lookup(struct student *head, int num)
{
struct student *p1,*p2;
p1=head;
if(head==NULL) //空链表时返回
{
printf("\n\t链表为空！\n");
return(head);
}
else
{
while(num!=p1->num &&p1->next !=NULL)
{
p2=p1;
p1=p1->next ;
}
if(num==p1->num ) //找到相应的学号则显示
{
printf("\t你查找的学生信息为：\n");
printf("\t学号为：%d\n",p1->num );
printf("\t姓名为：%s\n",p1->name );
printf("\t班级为：%s\n",p1->class_0 );
printf("\t程程序设计成绩为：%.2f\n",p1->c_prog );
printf("\t大学英语成绩为：%.2f\n",p1->eng );
printf("\t高等数学成绩为：%.2f\n",p1->math );
printf("\t平均成绩为：%.2f\n",p1->avg );
printf("\t学生名次为：%d\n",p1->order );
}
else // 学号不在链表内
printf("\t你输入的学号不在链表内！\n");
}
return(head);
}
//根据学生学号来修改学生的信息
struct student *Modify(struct student *head, int num)
{
struct student *p1,*p2;
struct student *stude;
stude=(struct student*)malloc(LEN);
p1=head;
if(head==NULL) //链表为空时不能改变信息
{
printf("\n\t链表为空！\n");
return(head);
}
else
{
while(num!=p1->num &&p1->next !=NULL)
{
p2=p1;
p1=p1->next;
}
if(num==p1->num ) // 找到相应的学号时
{
if(p1==head) //表头删除
head=p1->next ;
else //表中和表尾删除
p2->next =p1->next ;
printf("\t你要修改的学号为%d的先前信息为：\n",num);
printf("\t学号为：%d\n",p1->num );
printf("\t姓名为：%s\n",p1->name );
printf("\t班级为：%s\n",p1->class_0 );
printf("\n");
printf("\t程序设计成绩为：%.2f\n",p1->c_prog );
printf("\t大学英语成绩为：%.2f\n",p1->eng );
printf("\t高等数学成绩为：%.2f\n",p1->math );
printf("\t平均成绩为：%.2f\n",p1->avg );
printf("\t学生名次为：%d\n",p1->order );
printf("\n");
printf("\t请输入你要改变的成绩：（格式为：每输入一次回车）\n");
printf("\t请输入程序设计成绩：");
scanf("%f",&p1->c_prog );
printf("\t请输入大学英语成绩：");
scanf("%f",&p1->eng );
printf("\t请输入高等数学成绩：");
scanf("%f",&p1->math );
p1->c_prog =stude->c_prog ;
p1->eng =stude->eng ;
p1->math =stude->math ;
p1->avg =Statistic(p1);
head=insert(head,p1);
n=n-1;
}
else //找不到学号时
printf("\t你要修改的学号不在链表内！\n");
}
return(head);
}
//根据学生平均分来排名
struct student *order(struct student *head)
{
struct student *p;
int i=1;
p=head;
while(p!=NULL)
{
p->order =i;
i++;
p=p->next ;
}
return(head);
}
//根据输入的各科成绩来计算平均分
float Statistic(struct student *p)
{
p->avg =(p->c_prog +p->eng +p->math )/3;
return p->avg ;
}
void menu() //系统主界面
{
printf("\n\n\t\t = = =欢迎使用班级成绩管理系统= = =");
printf("\n\n\t\t 1.新建学生成绩表 ");
printf("\n\n\t\t 2.输出学生成绩表 ");
printf("\n\n\t\t 3.学生成绩排序 ");
printf("\n\n\t\t 4.按学号查找学生成绩信息");
printf("\n\n\t\t 5.按姓名修改学生成绩信息 ");
printf("\n\n\t\t 6.添加学生成绩信息 ");
printf("\n\n\t\t 7.按学号删除学生信息 ");
printf("\n\n\t\t ESC.退出系统 ");
printf("\n\n\t\t ------------------------------------");
printf("\n\n\t\t ********请您选择操作选项******** ");
printf("\n\t\t请输入您的选择(1-7)：");
}
void goon()
{
printf("按任意键继续！！！");
getch();
}
void exit()
{
system("cls");
printf("\n\n\n\t\t = = = = = = = = = = = = = = = = = =");
printf("\n\n\t\t = = =谢谢使用学生成绩管理系统= = =");
printf("\n\n\t\t = = = = = = = = = = = = = = = = = = \n\n");
}
//主函数
main()
{
struct student *head,*stu;
int Delete_num;
int lookup_num;
int Modify_num;
char ckey='a';
int istate=0;
do
{
system("cls"); //vc++清屏函数，包含在#include<stdlib.h>中
menu();
ckey=getch();
if(ckey=='1') //创建
{
system("cls");
head=create();
head=order(head);
Output(head);
istate=1; //记录链表是否有数据
goon();
}
else if((istate==0)&&(ckey!=Esc))
{
printf("\n\t错误：你必须先输入学生信息！！！");
goon();
}
else if(ckey=='2') ///显示
{
system("cls");
Output(head);
goon();
}
else if(ckey=='3') //排序
{
system("cls");
order(head);
Output(head);
goon();
}
else if(ckey=='4') //查找
{
system("cls");
printf(" \n\t请输入你要查找的学生学号：");
scanf("%d",&lookup_num);
head=Lookup(head,lookup_num);
head=order(head);
goon();
}
else if(ckey=='5') //修改
{
system("cls");
printf(" \n\t请输入你要修改学生信息的学号：");
scanf("%d",&Modify_num);
head=Modify(head,Modify_num);
head=order(head);
goon();
}
else if(ckey=='6') //插入
{
system("cls");
printf(" \n\t请输入你要插入的学生信息：\n\n");
stu=(struct student*)malloc(LEN);
printf("\t请输入学生信息，格式为：（每输入一项回车）\n");
printf("\t请输入学生学号：");
scanf("%d",&stu->num );
printf("\t请输入学生姓名：");
scanf("%s",&stu->name );
printf("\t请输入学生班级：");
scanf("%s",&stu->class_0 );
printf("\n");
printf("\t请输入程序设计成绩：");
scanf("%f",&stu->c_prog );
printf("\t请输入大学英语成绩：");
scanf("%f",&stu->eng );
printf("\t请输入高等数学成绩：");
scanf("%f",&stu->math );
printf("\n");
stu->avg=Statistic(stu); //求stu 的平均值
head=insert(head,stu);
head=order(head);
goon();
}
else if(ckey=='7') //删除
{
system("cls");
printf("\n\t请输入你要删除的学生学号");
scanf("%d",&Delete_num);
head=Delete(head,Delete_num);
head=order(head);
goon();
}
}
while(ckey!=Esc); //按键盘上的Esc键退出！！！
exit();
}