C语言学生成绩管理系统

Question

主要功能：
1.学生信息的录入、修改
2.课程信息的录入、修改
3.能完成对学生多门成绩的录入、修改
4.能统计学生的成绩，求学生的总分及平均分，并能根据学生的平均成绩进行排序
5.能查询学生的成绩，不及格科目及学生名单
6.能输出学生的成绩单

Answer 1

#include<stdio.h>
#include<stdlib.h>
#include<conio.h>
#include<dos.h>
#include<string.h>
#define LEN sizeof(struct student)
#define FORMAT "%-8d%-15s%-12.1lf%-12.1lf%-12.1lf%-12.1lf\n"
#define DATA stu[i].num,stu[i].name,stu[i].elec,stu[i].expe,stu[i].requ,stu[i].sum
struct student
{ int num;
char name[15];
double elec;
double expe;
double requ;
double sum;
};
struct student stu[50];
void in();
void show();
void order();
void del();
void modify();
void menu();
void insert();
void total();
void search();
void main()
{ int n;
menu();
scanf("%d",&n);
while(n)
{ switch(n)
{ case 1: in();break;
case 2: search();break;
case 3: del();break;
case 4: modify();break;
case 5: insert();break;
case 6: order();break;
case 7: total();break;
default:break;
}
getch();
menu();
scanf("%d",&n);
}
}void in()
{ int i,m=0;
char ch[2];
FILE *fp;
if((fp=fopen("data.txt","a+"))==NULL)
{ printf("can not open\n");return;}
while(!feof(fp)) {
if(fread(&stu[m] ,LEN,1,fp)==1)
m++;
}
fclose(fp);
if(m==0)
printf("No record!\n");
else
{
system("cls");
show();
}
if((fp=fopen("data.txt","wb"))==NULL)
{ printf("can not open\n");return;}
for(i=0;i<m;i++)
{
fwrite(&stu[i] ,LEN,1,fp);
}
printf("please input(y/n):");
scanf("%s",ch);
while(strcmp(ch,"Y")==0||strcmp(ch,"y")==0)
{
printf("number:");
scanf("%d",&stu[m].num);/*输入学生学号*/
for(i=0;i<m;i++)
if(stu[i].num==stu[m].num)
{
printf("the number is existing,press any to continue!");
getch();
fclose(fp);
return;
}
printf("name:");
scanf("%s",stu[m].name);
printf("elective:");
scanf("%lf",&stu[m].elec);
printf("experiment:");
scanf("%lf",&stu[m].expe);
printf("required course:");
scanf("%lf",&stu[m].requ);
stu[m].sum=stu[m].elec+stu[m].expe+stu[m].requ;
if(fwrite(&stu[m],LEN,1,fp)!=1)/*将新录入的信息写入指定的磁盘文件*/
{ printf("can not save!"); getch(); }
else { printf("%s saved!\n",stu[m].name);m++;}
printf("continue?(y/n):");/*询问是否继续*/
scanf("%s",ch);
}
fclose(fp);
printf("OK!\n");
}void show()
{ FILE *fp;
int i,m=0;
fp=fopen("data.txt","rb");
while(!feof(fp))
{
if(fread(&stu[m] ,LEN,1,fp)==1)
m++;
}
fclose(fp);
printf("number name elective experiment required sum\t\n");
for(i=0;i<m;i++)
{
printf(FORMAT,DATA);//
}
}

void menu()
{
system("cls");
printf("\n\n\n\n\n");
printf("\t\t|---------------------STUDENT-------------------|\n");
printf("\t\t|\t 0. exit |\n");
printf("\t\t|\t 1. input record |\n");
printf("\t\t|\t 2. search record |\n");
printf("\t\t|\t 3. delete record |\n");
printf("\t\t|\t 4. modify record |\n");
printf("\t\t|\t 5. insert record |\n");
printf("\t\t|\t 6. order |\n");
printf("\t\t|\t 7. number |\n");
printf("\t\t|-----------------------------------------------|\n\n");
printf("\t\t\tchoose(0-7):");
}void order()/*自定义排序函数*/
{ FILE *fp;
struct student t;
int i=0,j=0,m=0;
if((fp=fopen("data.txt","r+"))==NULL)
{
printf("can not open!\n");
return;
}
while(!feof(fp))
if(fread(&stu[m] ,LEN,1,fp)==1)
m++;
fclose(fp);
if(m==0)
{
printf("no record!\n");
return;
}
if((fp=fopen("data.txt","wb"))==NULL)
{
printf("can not open\n");
return;}
for(i=0;i<m-1;i++)
for(j=i+1;j<m;j++)
if(stu[i].sum<stu[j].sum)
{ t=stu[i];stu[i]=stu[j];stu[j]=t;}
if((fp=fopen("data.txt","wb"))==NULL)
{ printf("can not open\n");return;}
for(i=0;i<m;i++)
if(fwrite(&stu[i] ,LEN,1,fp)!=1)
{
printf("%s can not save!\n");
getch();
}
fclose(fp);
printf("save successfully\n");
}
void del()/*自定义删除函数*/
{FILE *fp;<br> int snum,i,j,m=0;<br> char ch[2];<br> if((fp=fopen("data.txt","r+"))==NULL)<br> { printf("can not open\n");return;}
while(!feof(fp)) if(fread(&stu[m],LEN,1,fp)==1) m++;
fclose(fp);
if(m==0)
{
printf("no record!\n");
return;
}
printf("please input the number:");
scanf("%d",&snum);
for(i=0;i<m;i++)
if(snum==stu[i].num)
break;
printf("find the student,delete?(y/n)");
scanf("%s",ch);
if(strcmp(ch,"Y")==0||strcmp(ch,"y")==0)/*判断是否要进行删除*/
for(j=i;j<m;j++)
stu[j]=stu[j+1];/*将后一个记录移到前一个记录的位置*/
m--;/*记录的总个数减1*/
if((fp=fopen("data.txt","wb"))==NULL)
{ printf("can not open\n");return;}
for(j=0;j<m;j++)/*将更改后的记录重新写入指定的磁盘文件中*/
if(fwrite(&stu[j] ,LEN,1,fp)!=1)
{ printf("can not save!\n");
getch();}
fclose(fp);
printf("delete successfully!\n");
}void search()/*自定义查找函数*/
{ FILE *fp;
int snum,i,m=0;
char ch[2];
if((fp=fopen("data.txt","rb"))==NULL)
{ printf("can not open\n");return;}
while(!feof(fp)) if(fread(&stu[m],LEN,1,fp)==1) m++;
fclose(fp);
if(m==0) {printf("no record!\n");return;}
printf("please input the number:");
scanf("%d",&snum);
for(i=0;i<m;i++)
if(snum==stu[i].num)/*查找输入的学号是否在记录中*/
{ printf("find the student,show?(y/n)");
scanf("%s",ch);
if(strcmp(ch,"Y")==0||strcmp(ch,"y")==0)
{
printf("number name elective experiment required sum\t\n");
printf(FORMAT,DATA);/*将查找出的结果按指定格式输出*/
break;
}
}
if(i==m) printf("can not find the student!\n");/*未找到要查找的信息*/
}void modify()/*自定义修改函数*/
{ FILE *fp;
int i,j,m=0,snum;
if((fp=fopen("data.txt","r+"))==NULL)
{ printf("can not open\n");return;}
while(!feof(fp))
if(fread(&stu[m],LEN,1,fp)==1) m++;
if(m==0) {printf("no record!\n");<br> fclose(fp);<br> return;<br> }
printf("please input the number of the student which do you want to modify!\n");
scanf("%d",&snum);
for(i=0;i<m;i++)
if(snum==stu[i].num)/*检索记录中是否有要修改的信息*/
break;
printf("find the student!you can modify!\n");
printf("name:\n");
scanf("%s",stu[i].name);/*输入名字*/
printf("\nelective:");
scanf("%lf",&stu[i].elec);/*输入选修课成绩*/
printf("\nexperiment:");
scanf("%lf",&stu[i].expe);/*输入实验课成绩*/
printf("\nrequired course:");
scanf("%lf",&stu[i].requ);/*输入必修课成绩*/
stu[i].sum=stu[i].elec+stu[i].expe+stu[i].requ;
if((fp=fopen("data.txt","wb"))==NULL)
{ printf("can not open\n");return;}
for(j=0;j<m;j++)
if(fwrite(&stu[j] ,LEN,1,fp)!=1)
{ printf("can not save!"); getch(); }
fclose(fp);
}void insert()
{ FILE *fp;
int i,j,k,m=0,snum;
if((fp=fopen("data.txt","r+"))==NULL)
{ printf("can not open\n");return;}
while(!feof(fp))
if(fread(&stu[m],LEN,1,fp)==1) m++;
if(m==0) {printf("no record!\n");<br> fclose(fp);<br> return;<br> }
printf("please input position where do you want to insert!(input the number)\n");
scanf("%d",&snum);
for(i=0;i<m;i++)
if(snum==stu[i].num)
break;
for(j=m-1;j>i;j--)
stu[j+1]=stu[j];
printf("now please input the new information.\n");
printf("number:");
scanf("%d",&stu[i+1].num);
for(k=0;k<m;k++)
if(stu[k].num==stu[i+1].num)
{
printf("the number is existing,press any to continue!");
getch();
fclose(fp);
return;
}
printf("name:\n");
scanf("%s",stu[i+1].name);
printf("\nelective:");
scanf("%lf",&stu[i+1].elec);
printf("\nexperiment:");
scanf("%lf",&stu[i+1].expe);
printf("\nrequired course:");
scanf("%lf",&stu[i+1].requ);
stu[i+1].sum=stu[i+1].elec+stu[i+1].expe+stu[i+1].requ;
if((fp=fopen("data.txt","wb"))==NULL)
{ printf("can not open\n");return;}
for(k=0;k<=m;k++)
if(fwrite(&stu[k] ,LEN,1,fp)!=1)
{ printf("can not save!"); getch(); }
fclose(fp);
}void total()
{ FILE *fp;
int m=0;
if((fp=fopen("data.txt","r+"))==NULL)
{ printf("can not open\n");return;}
while(!feof(fp))
if(fread(&stu[m],LEN,1,fp)==1)
m++;
if(m==0) {printf("no record!\n");fclose(fp);return;}
printf("the class are %d students!\n",m);
fclose(fp);
}