一、用C语言 设计一学生成绩管理系统，要求： 1. 学生成绩的信息包括：学号、姓名、性别、年龄、系别、班级、
/*头文件
学生成绩管理系统c代码*/
#include <stdio.h>
#include<dos.h>
#include<stdlib.h> /*其它说明*/
#include<string.h> /*字符串函数*/
#include<mem.h> /*内存操作函数*/
#include<ctype.h> /*字符操作函数*/
#include<alloc.h> /*动态地址分配函数*/
#define len sizeof(student)
typedef struct stu /*定义结构体数组用于缓存数据*/
{
char num[6];
char name[5];
int score[3];
int sum;
float average;
int order;
struct stu *next;
}student;
/*函数原型*/
student *init(); /*初始化函数*/
int menu_select(); /*菜单函数*/
student *create(); /*创建链表*/
void print(student *head); /* 显示全部记录*/
void search(student *head); /*查找记录*/
student *delete(student *head); /*删除记录*/
student *sort(student *head); /*排序*/
student *insert(student *head,student *newnode); /*插入记录*/
void save(student *head); /*保存文件*/
student *load(); /*读文件*/
/*主函数界面*/
main()
{
student *head,newnode;
head=init(); /*链表初始化,使head的值为null*/
for(;;) /*循环无限次*/
{
switch(menu_select())
{
case 1:head=create();break;
case 2:print(head);break;
case 3:search(head);break;
case 4:head=delete(head);break;
case 5:head=sort(head);break;
case 6:head=insert(head,&newnode);break; /*&newnode表示返回地址*/
case 7:save(head);break;
case 8:head=load(); break;
case 9:exit(0); /*如菜单返回值为9则程序结束*/
}
}
}
/*初始化函数*/
student *init()
{
return null; /*返回空指针*/
}
/*菜单选择函数*/
menu_select()
{
int n;
struct date d; /*定义时间结构体*/
getdate(&d); /*读取系统日期并把它放到结构体d中*/
printf("press any key to enter the menu......"); /*按任一键进入主菜单*/
getch(); /*从键盘读取一个字符,但不显示于屏幕*/
clrscr(); /*清屏*/
printf("********************************************************************************\n");
printf("\t\t welcome to\n");
printf("\n\t\t the student score manage system\n");
printf("*************************************menu***************************************\n");
printf("\t\t\t1. enter the record\n"); /*输入学生成绩记录*/
printf("\t\t\t2. print the record\n"); /*显示*/
printf("\t\t\t3. search record on name\n"); /*寻找*/
printf("\t\t\t4. delete a record\n"); /*删除*/
printf("\t\t\t5. sort to make new a file\n"); /*排序*/
printf("\t\t\t6. insert record to list\n"); /*插入*/
printf("\t\t\t7. save the file\n"); /*保存*/
printf("\t\t\t8. load the file\n"); /*读取*/
printf("\t\t\t9. quit\n"); /*退出*/
printf("\n\t\t made by hu haihong.\n");
printf("********************************************************************************\n");
printf("\t\t\t\t%d\\%d\\%d\n",d.da_year,d.da_mon,d.da_day); /*显示当前系统日期*/
do{
printf("\n\t\t\tenter your choice(1~9):");
scanf("%d",&n);
}while(n<1||n>9); /*如果选择项不在1~9之间则重输*/
return(n); /*返回选择项，主函数根据该数调用相应的函数*/
}
/*输入函数*/
student *create()
{
int i,s;
student *head=null,*p; /* 定义函数.此函数带回一个指向链表头的指针*/
clrscr();
for(;;)
{p=(student *)malloc(len); /*开辟一个新的单元*/
if(!p) /*如果指针p为空*/
{printf("\nout of memory."); /*输出内存溢出*/
return (head); /*返回头指针,下同*/
}
printf("enter the num(0:list end):");
scanf("%s",p->num);
if(p->num[0]=='0') break; /*如果学号首字符为0则结束输入*/
printf("enter the name:");
scanf("%s",p->name);
printf("please enter the %d scores\n",3); /*提示开始输入成绩*/
s=0; /*计算每个学生的总分，初值为0*/
for(i=0;i<3;i++) /*3门课程循环3次*/
{
do{
printf("score%d:",i+1);
scanf("%d",&p->score[i]);
if(p->score[i]<0 || p->score[i]>100) /*确保成绩在0~100之间*/
printf("data error,please enter again.\n");
}while(p->score[i]<0 || p->score[i]>100);
s=s+p->score[i]; /*累加各门成绩*/
}
p->sum=s; /*将总分保存*/
p->average=(float)s/3; /*先用强制类型转换将s转换成float型,再求平均值*/
p->order=0; /*未排序前此值为0*/
p->next=head; /*将头结点做为新输入结点的后继结点*/
head=p; /*新输入结点为新的头结点*/
}
return(head);
}
/* 显示全部记录函数*/
void print(student *head)
{
int i=0; /* 统计记录条数*/
student *p; /*移动指针*/
clrscr();
p=head; /*初值为头指针*/
printf("\n************************************student************************************\n");
printf("-------------------------------------------------------------------------------\n");
printf("| rec | num | name | sc1 | sc2 | sc3 | sum | ave | order |\n");
printf("-------------------------------------------------------------------------------\n");
while(p!=null)
{
i++;
printf("| %3d | %4s | %-4s | %3d | %3d | %3d | %3d | %4.2f | %-5d|\n",
i, p->num,p->name,p->score[0],p->score[1],p->score[2],p->sum,p->average,p->order);
p=p->next;
}
printf("-------------------------------------------------------------------------------\n");
printf("**************************************end**************************************\n");
}
/*查找记录函数*/
void search(student *head)
{
student *p; /* 移动指针*/
char s[5]; /*存放姓名用的字符数组*/
clrscr();
printf("please enter name for searching.\n");
scanf("%s",s);
p=head; /*将头指针赋给p*/
while(strcmp(p->name,s) && p != null) /*当记录的姓名不是要找的，或指针不为空时*/
p=p->next; /*移动指针，指向下一结点*/
if(p!=null) /*如果指针不为空*/
{printf("\n*************************************found************************************\n");
printf("-------------------------------------------------------------------------------\n");
printf("| num | name | sc1 | sc2 | sc3 | sum | ave | order |\n");
printf("-------------------------------------------------------------------------------\n");
printf("| %4s | %4s | %3d | %3d | %3d | %3d | %4.2f | %-5d|\n",
p->num,p->name,p->score[0],p->score[1],p->score[2],p->sum,p->average,p->order);
printf("-------------------------------------------------------------------------------\n");
printf("***************************************end**************************************\n");
}
else
printf("\nthere is no num %s student on the list.\n",s); /*显示没有该学生*/
}
/*删除记录函数*/
student *delete(student *head)
{int n;
student *p1,*p2; /*p1为查找到要删除的结点指针，p2为其前驱指针*/
char c,s[6]; /*s[6]用来存放学号,c用来输入字母*/
clrscr();
printf("please enter the deleted num: ");
scanf("%s",s);
p1=p2=head; /*给p1和p2赋初值头指针*/
while(strcmp(p1->num,s) && p1 != null) /*当记录的学号不是要找的，或指针不为空时*/
{p2=p1; /*将p1指针值赋给p2作为p1的前驱指针*/
p1=p1->next; /*将p1指针指向下一条记录*/
}
if(strcmp(p1->num,s)==0) /*学号找到了*/
{printf("**************************************found************************************\n");
printf("-------------------------------------------------------------------------------\n");
printf("| num | name | sc1 | sc2 | sc3 | sum | ave | order |\n");
printf("-------------------------------------------------------------------------------\n");
printf("| %4s | %4s | %3d | %3d | %3d | %3d | %4.2f | %-5d|\n",
p1->num,p1->name,p1->score[0],p1->score[1],p1->score[2],p1->sum,p1->average,p1->order);
printf("-------------------------------------------------------------------------------\n");
printf("***************************************end**************************************\n");
printf("are you sure to delete the student y/n ?"); /*提示是否要删除,输入y删除,n则退出*/
for(;;)
{scanf("%c",&c);
if(c=='n'||c=='n') break; /*如果不删除,则跳出本循环*/
if(c=='y'||c=='y')
{
if(p1==head) /*若p1==head，说明被删结点是首结点*/
head=p1->next; /*把第二个结点地址赋予head*/
else
p2->next=p1->next; /*否则将一下结点地址赋给前一结点地址*/
n=n-1;
printf("\nnum %s student have been deleted.\n",s);
printf("don't forget to save.\n");break; /*删除后就跳出循环*/
}
}
}
else
printf("\nthere is no num %s student on the list.\n",s); /*找不到该结点*/
return(head);
}
/*排序函数*/
student *sort(student *head)
{int i=0; /*保存名次*/
student *p1,*p2,*t,*temp; /*定义临时指针*/
temp=head->next; /*将原表的头指针所指的下一个结点作头指针*/
head->next=null; /*第一个结点为新表的头结点*/
while(temp!=null) /*当原表不为空时，进行排序*/
{
t=temp; /*取原表的头结点*/
temp=temp->next; /*原表头结点指针后移*/
p1=head; /*设定移动指针p1，从头指针开始*/
p2=head; /*设定移动指针p2做为p1的前驱，初值为头指针*/
while(t->average<p1->average&&p1!=null) /*作成绩平均分比较*/
{
p2=p1; /*待排序点值小，则新表指针后移*/
p1=p1->next;
}
if(p1==p2) /*p1==p2，说明待排序点值大，应排在首位*/
{
t->next=p1; /*待排序点的后继为p*/
head=t; /*新头结点为待排序点*/
}
else /*待排序点应插入在中间某个位置p2和p1之间，如p为空则是尾部*/
{
t->next=p1; /*t的后继是p1*/
p2->next=t; /*p2的后继是t*/
}
}
p1=head; /*已排好序的头指针赋给p1，准备填写名次*/
while(p1!=null) /*当p1不为空时，进行下列操作*/
{
i++; /*结点序号*/
p1->order=i; /*将结点序号赋值给名次*/
p1=p1->next; /*指针后移*/
}
printf("sorting is sucessful.\n"); /*排序成功*/
return (head);
}
/*插入记录函数*/
student *insert(student *head,student *newnode)
{student *p0,*p1,*p2;
int n,sum1,i;
p1=head; /*使p1指向第一个结点*/
p0=newnode; /*p0指向要插入的结点*/
printf("\nplease enter a newnode record.\n"); /*提示输入记录信息*/
printf("enter the num:");
scanf("%s",newnode->num);
printf("enter the name:");
scanf("%s",newnode->name);
printf("please enter the %d scores.\n",3);
sum1=0; /*保存新记录的总分，初值为0*/
for(i=0;i<3;i++)
{
do{
printf("score%d:",i+1);
scanf("%d",&newnode->score[i]);
if(newnode->score[i]>100||newnode->score[i]<0)
printf("data error,please enter again.\n");
}while(newnode->score[i]>100||newnode->score[i]<0);
sum1=sum1+newnode->score[i]; /*累加各门成绩*/
}
newnode->sum=sum1; /*将总分存入新记录中*/
newnode->average=(float)sum1/3;
newnode->order=0;
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->average<p1->average)&&(p1->next!=null))
{p2=p1; /*使p2指向刚才p1指向的结点*/
p1=p1->next; /*p1后移一个结点*/
}
if(p0->average>=p1->average)
{if(head==p1)head=p0; /*插到原来第一个结点之前*/
else p2->next=p0; /*插到p2指向的结点之后*/
p0->next=p1;}
else
{p1->next=p0;p0->next=null;} /*插到最后的结点之后*/
}
n=n+1; /*结点数加1*/
head=sort(head); /*调用排序的函数,将学生成绩重新排序*/
printf("\nstudent %s have been inserted.\n",newnode->name);
printf("don't forget to save the newnode file.\n");
return(head);
}
/*保存数据到文件函数*/
void save(student *head)
{file *fp; /*定义指向文件的指针*/
student *p; /* 定义移动指针*/
char outfile[10];
printf("enter outfile name,for example c:\\score\n");
scanf("%s",outfile);
if((fp=fopen(outfile,"wb"))==null) /*为输出打开一个二进制文件,为只写方式*/
{
printf("cannot open the file\n");
return; /*若打不开则返回菜单*/
}
printf("\nsaving the file......\n");
p=head; /*移动指针从头指针开始*/
while(p!=null) /*如p不为空*/
{
fwrite(p,len,1,fp); /*写入一条记录*/
p=p->next; /*指针后移*/
}
fclose(fp); /*关闭文件*/
printf("save the file successfully!\n");
}
/* 从文件读数据函数*/
student *load()
{student *p1,*p2,*head=null; /*定义记录指针变量*/
file *fp; /* 定义指向文件的指针*/
char infile[10];
printf("enter infile name,for example c:\\score\n");
scanf("%s",infile);
if((fp=fopen(infile,"rb"))==null) /*打开一个二进制文件，为只读方式*/
{
printf("can not open the file.\n");
return(head);
}
printf("\nloading the file!\n");
p1=(student *)malloc(len); /*开辟一个新单元*/
if(!p1)
{
printf("out of memory!\n");
return(head);
}
head=p1; /*申请到空间，将其作为头指针*/
while(!feof(fp)) /*循环读数据直到文件尾结束*/
{
if(fread(p1,len,1,fp)!=1) break; /*如果没读到数据，跳出循环*/
p1->next=(student *)malloc(len); /*为下一个结点开辟空间*/
if(!p1->next)
{
printf("out of memory!\n");
return (head);
}
p2=p1; /*使p2指向刚才p1指向的结点*/
p1=p1->next; /*指针后移，新读入数据链到当前表尾*/
}
p2->next=null; /*最后一个结点的后继指针为空*/
fclose(fp);
printf("you have success to read data from the file!\n");
return (head);
}
