如何用C语言编写"学生成绩管理系统"

Question

 用户交互界面。
设计用户界面，由用户界面进入相应操作。
 输入学生信息。
每个学生包括的信息为：学号、姓名、班级、学期、课程名称、课程成绩（课程名可自拟）。其中学号唯一，不可重复。
 编辑学生信息。
1．修改某学生的制定信息。
2．删除某学生的所有信息。
 成绩统计
1．统计某一门课程的平均成绩，将统计结构在屏幕上显示。
2．能按学生某门课程成绩排序，并显示结果。
 学生信息查询
1．按姓名查询：输入学生姓名，显示该学生的所有信息。
2．按学号查找：输入学生学号，显示该学生的所有信息。
3．按某一门课程的成绩查询：能够分屏显示。
4．按班级查询：查询某一班级的所有学生信息。
 帮助系统
显示帮助文件。
 退出系统
2) 附加：以上输入的所有学生信息及修改后的更新信息都可以文件的形式保存，以便今后直接调用。

Answer 1

#include<stdio.h>
#include<stdlib.h>
#include<conio.h>
#include<string.h>
struct student{
int id;
char name[10];
int age;
char sex[10];
char birthady[20];
int tel;
char nativeplace[50];
}st[50];
int i=0;
void shuru() {
char a;
do{
printf("\n请输入学号:");
scanf("%d",&st[i].id);
fflush(stdin);
printf("\n请输入姓名:");
gets(st[i].name);
printf("\n") ;
printf("请输入年龄:");
scanf("%d",&st[i].age);
fflush(stdin);
printf("\n请输入姓别:");
gets(st[i].sex);
fflush(stdin);
printf("\n请输入生日:");
gets(st[i].birthady);
printf("\n请输入电话:");
scanf("%d",&st[i].tel);
fflush(stdin);
printf("\n请输入籍贯:");
gets(st[i].nativeplace);
printf("\n是否继续输入另外一个学生信息?(y/n)");
fflush(stdin);
a=getchar();
i++;
}while(a=='y' && i<=50);

}

void xianshi()
{
int j;
printf("\t学号\t姓名\t年龄\t性别\t生日\t\t电话\t籍贯\n");
for(j=0;j<i;j++)
printf("\t%d\t%s\t%d\t%s\t%s\t%d\t%s\n",
st[j].id,st[j].name,st[j].age,st[j].sex,st[j].birthady,st[j].tel,st[j].nativeplace);
}

void paixu() //按年龄从大到小排序函数
{
int j,k;
int temp;
for(j=0;j<i;j++)
{
for(k=0;k<i-1-j;k++)
{
if(st[k].age<st[k+1].age)
{
temp=st[k].age;
st[k].age=st[k+1].age;
st[k+1].age=temp;
}
}
}
xianshi(); //排序后输出
}

void chazhao()
{
int m;
char name[20],b;
do
{
printf("\n请输入想查找的学生姓名:");
fflush(stdin);
gets(name);
for(m=0;m<i;m++)
{
if(strcmp(name,st[m].name)==0)
{
printf("\n\t您查找的学生在第%d个位置找到了!!!\n",m+1);
break;
}
}
if(m>=20)
printf("\n\t没有找到这个学生!!!\n");
else
{
printf("\t学号\t姓名\t年龄\t性别\t生日\t\t电话\t籍贯\n");
printf("\t%d\t%s\t%d\t%s\t%s\t%d\t%s\n",
st[m].id,st[m].name,st[m].age,st[m].sex,st[m].birthady,st[m].tel,st[m].nativeplace);
}
printf("\n是否查找另一个学生的信息?(y/n)");
fflush(stdin);
b=getchar();

}while(b=='y');

}

void shanchu()
{
char name[20],c;
int a,b;
do
{
printf("\n请输入要删除的学生姓名:\n");
fflush(stdin);
gets(name);
for(a=0;a<i;a++)
{
if(strcmp(name,st[a].name)==0)
break;
}

for(b=a;b<i;b++)
st[b]=st[b+1];
if(a>i)
printf("\t没有找到这个学生!!!\n");

else
{
i--;
xianshi();
}

printf("\n是否继续删除另一个学生信息?(y/n) ");
fflush(stdin);
c=getchar();
}while(c=='y');

}

void charu()
{
shuru();
paixu();

}

void main() //主函数
{
int change;
do{
system("cls");
printf("============================学生信息管理系统===================================\n");
printf("\t\t一： 输入学生信息\n");
printf("\t\t二： 显示学生信息\n");
printf("\t\t三： 查找学生信息\n");
printf("\t\t四： 删除学生信息\n");
printf("\t\t五： 插入学生信息\n");
printf("\t\t六： 退出程序\n");
fflush(stdin);
printf("\t\t请输入功能选项：");
scanf("%d",&change);
switch(change)
{
case 1:
shuru(); break;
case 2:
xianshi(); break;
case 3:
chazhao(); break;
case 4:
shanchu(); break;
case 5:
charu(); break;
case 6:
break;
}
getch();
}while(change!=6);
}

Answer 2

#include<stdio.h> /*引用库函数*/
#include<stdlib.h>
#include<ctype.h>
#include<string.h>
typedef struct /*定义结构体数组*/
{
char num[10]; /*学号*/
char name[20]; /*姓名*/
int score; /*成绩*/
}Student;
Student stu[80]; /*结构体数组变量*/
int menu_select() /*菜单函数*/
{
char c;
do{
system("cls"); /*运行前清屏*/
printf("\t\t****Students' Grade Management System****\n"); /*菜单选择*/
printf("\t\t | 1. Input Records |\n");
printf("\t\t | 2. Display All Records |\n");
printf("\t\t | 3. Sort |\n");
printf("\t\t | 4. Insert a Record |\n");
printf("\t\t | 5. Delete a Record |\n");
printf("\t\t | 6. Query |\n");
printf("\t\t | 7. Statistic |\n");
printf("\t\t | 8. Add Records from a Text File|\n");
printf("\t\t | 9. Write to a Text file |\n");
printf("\t\t | 0. Quit |\n");
printf("\t\t*****************************************\n");
printf("\t\t\tGive your Choice(0-9):");
c=getchar(); /*读入选择*/
}while(c<'0'||c>'9');
return(c-'0'); /*返回选择*/
}
int Input(Student stud[],int n) /*输入若干条记录*/
{int i=0;
char sign,x[10]; /*x[10]为清除多余的数据所用*/
while(sign!='n'&&sign!='N') /*判断*/
{ printf("\t\t\tstudent's num:"); /*交互输入*/
scanf("\t\t\t%s",stud[n+i].num);
printf("\t\t\tstudent's name:");
scanf("\t\t\t%s",stud[n+i].name);
printf("\t\t\tstudent's score:");
scanf("\t\t\t%d",&stud[n+i].score);
gets(x); /*清除多余的输入*/
printf("\t\t\tany more records?(Y/N)");
scanf("\t\t\t%c",&sign); /*输入判断*/
i++;
}
return(n+i);
}
void Display(Student stud[],int n) /*显示所有记录*/
{
int i;
printf("\t\t\t-----------------------------------\n"); /*格式头*/
printf("\t\t\tnumber name score\n");
printf("\t\t\t-----------------------------------\n");
for(i=1;i<n+1;i++) /*循环输入*/
{
printf("\t\t\t%-16s%-15s%d\n",stud[i-1].num,stud[i-1].name,stud[i-1].score);
if(i>1&&i%10==0) /*每十个暂停*/
{printf("\t\t\t-----------------------------------\n"); /*格式*/
printf("\t\t\t");
system("pause");
printf("\t\t\t-----------------------------------\n");
}
}
printf("\t\t\t");
system("pause");
}
void Sort_by_num(Student stud[],int n) /*按学号排序*/
{ int i,j,*p,*q,s;
char t[10];
for(i=0;i<n-1;i++) /*冒泡法排序*/
for(j=0;j<n-1-i;j++)
if(strcmp(stud[j].num,stud[j+1].num)>0)
{strcpy(t,stud[j+1].num);
strcpy(stud[j+1].num,stud[j].num);
strcpy(stud[j].num,t);
strcpy(t,stud[j+1].name);
strcpy(stud[j+1].name,stud[j].name);
strcpy(stud[j].name,t);
p=&stud[j+1].score;
q=&stud[j].score;
s=*p;
*p=*q;
*q=s;
}
}
int Insert_a_record(Student stud[],int n) /*插入一条记录*/
{char x[10]; /*清除多余输入所用*/
printf("\t\t\tstudent's num:"); /*交互式输入*/
scanf("\t\t\t%s",stud[n].num);
printf("\t\t\tstudent's name:");
scanf("\t\t\t%s",stud[n].name);
printf("\t\t\tstudent's score:");
scanf("\t\t\t%d",&stud[n].score);
gets(x);
n++;
Sort_by_num(stud,n); /*调用排序函数*/
printf("\t\t\tInsert Successed!\n"); /*返回成功信息*/
return(n);
}
int Delete_a_record(Student stud[],int n) /*按姓名查找，删除一条记录*/
{ char s[20];
int i=0,j;
printf("\t\t\ttell me his(her) name:"); /*交互式问寻*/
scanf("%s",s);
while(strcmp(stud[i].name,s)!=0&&i<n) i++; /*查找判断*/
if(i==n)
{ printf("\t\t\tnot find!\n"); /*返回失败信息*/
return(n);
}
for(j=i;j<n-1;j++) /*删除操作*/
{
strcpy(stud[j].num,stud[j+1].num);
strcpy(stud[j].name,stud[j+1].name);
stud[j].score=stud[j+1].score;
}
printf("\t\t\tDelete Successed!\n"); /*返回成功信息*/
return(n-1);
}
void Query_a_record(Student stud[],int n) /*查找并显示一个记录*/
{ char s[20];
int i=0;
printf("\t\t\tinput his(her) name:"); /*交互式输入*/
scanf("\t\t\t%s",s);
while(strcmp(stud[i].name,s)!=0&&i<n) i++; /*查找判断*/
if(i==n)
{ printf("\t\t\tnot find!\n"); /*输入失败信息*/
return;

}
printf("\t\t\this(her) number:%s\n",stud[i].num); /*输出该学生信息*/
printf("\t\t\this(her) score:%d\n",stud[i].score);
}
void Statistic(Student stud[],int n) /*新增功能，输出统计信息*/
{ int i,j=0,k=0,sum=0;
float aver; /*成绩平均值*/
for(i=0;i<n;i++) /*循环输入判断*/
{
sum+=stud[i].score;
if(stud[j].score>stud[i].score) j=i;
if(stud[k].score<stud[i].score) k=i;
}
aver=1.0*sum/n;
printf("\t\t\tthere are %d records.\n",n); /*总共记录数*/
printf("\t\t\tthe hignest score:\n"); /*最高分*/
printf("\t\t\tnumber:%s name:%s score:%d\n",stud[j].num,stud[j].name,stud[j].score);
printf("\t\t\tthe lowest score:\n"); /*最低分*/
printf("\t\t\tnumber:%s name:%s score:%d\n",stud[k].num,stud[k].name,stud[k].score);
printf("\t\t\tthe average score is %5.2f\n",aver); /*平均分*/
}
int AddfromText(Student stud[],int n) /*从文件中读入数据*/
{ int i=0,num;
FILE *fp; /*定义文件指针*/
char filename[20]; /*定义文件名*/
printf("\t\t\tInput the filename:");
scanf("\t\t\t%s",filename); /*输入文件名*/
if((fp=fopen(filename,"rb"))==NULL) /*打开文件*/
{ printf("\t\t\tcann't open the file\n"); /*打开失败信息*/
printf("\t\t\t");
system("pause");
return(n);
}
fscanf(fp,"%d",&num); /*读入总记录量*/
while(i<num) /*循环读入数据*/
{
fscanf(fp,"%s%s%d",stud[n+i].num,stud[n+i].name,&stud[n+i].score);
i++;
}
n+=num;
fclose(fp); /*关闭文件*/
printf("\t\t\tSuccessed!\n");
printf("\t\t\t");
system("pause");
return(n);
}
void WritetoText(Student stud[],int n) /*将所有记录写入文件*/
{
int i=0;
FILE *fp; /*定义文件指针*/
char filename[20]; /*定义文件名*/
printf("\t\t\tWrite Records to a Text File\n"); /*输入文件名*/
printf("\t\t\tInput the filename:");
scanf("\t\t\t%s",filename);
if((fp=fopen(filename,"w"))==NULL) /*打开文件*/
{
printf("\t\t\tcann't open the file\n");
system("pause");
return;
}
fprintf(fp,"%d\n",n); /*循环写入数据*/
while(i<n)
{
fprintf(fp,"%-16s%-15s%d\n",stud[i].num,stud[i].name,stud[i].score);
i++;
}
fclose(fp); /*关闭文件*/
printf("Successed!\n"); /*返回成功信息*/
}
void main() /*主函数*/
{
int n=0;
for(;;)
{
switch(menu_select()) /*选择判断*/
{
case 1:
printf("\t\t\tInput Records\n"); /*输入若干条记录*/
n=Input(stu,n);
break;
case 2:
printf("\t\t\tDisplay All Records\n"); /*显示所有记录*/
Display(stu,n);
break;
case 3:
printf("\t\t\tSort\n");
Sort_by_num(stu,n); /*按学号排序*/
printf("\t\t\tSort Suceessed!\n");
printf("\t\t\t");
system("pause");
break;
case 4:
printf("\t\t\tInsert a Record\n");
n=Insert_a_record(stu,n); /*插入一条记录*/
printf("\t\t\t");
system("pause");
break;
case 5:
printf("\t\t\tDelete a Record\n");
n=Delete_a_record(stu,n); /*按姓名查找，删除一条记录*/
printf("\t\t\t");
system("pause");
break;
case 6:
printf("\t\t\tQuery\n");
Query_a_record(stu,n); /*查找并显示一个记录*/
printf("\t\t\t");
system("pause");
break;
case 7:
printf("\t\t\tStatistic\n");
Statistic(stu,n); /*新增功能，输出统计信息*/
printf("\t\t\t");
system("pause");
break;
case 8:
printf("\t\t\tAdd Records from a Text File\n");
n=AddfromText(stu,n); /*新增功能，输出统计信息*/
break;
case 9:
printf("\t\t\tWrite to a Text file\n");
WritetoText(stu,n); /*循环写入数据*/
printf("\t\t\t");
system("pause");
break;
case 0:
printf("\t\t\tHave a Good Luck,Bye-bye!\n"); /*结束程序*/
printf("\t\t\t");
system("pause");
exit(0);
}
}
}

Answer 3

有啊，你看看行不？
#include<stdio.h> /*引用库函数*/
#include<stdlib.h>
#include<ctype.h>
#include<string.h>
typedef struct /*定义结构体数组*/
{
char num[10]; /*学号*/
char name[20]; /*姓名*/
int score; /*成绩*/
}Student;
Student stu[80]; /*结构体数组变量*/
int menu_select() /*菜单函数*/
{
char c;
do{
system("cls"); /*运行前清屏*/
printf("\t\t****Students' Grade Management System****\n"); /*菜单选择*/
printf("\t\t | 1. Input Records |\n");
printf("\t\t | 2. Display All Records |\n");
printf("\t\t | 3. Sort |\n");
printf("\t\t | 4. Insert a Record |\n");
printf("\t\t | 5. Delete a Record |\n");
printf("\t\t | 6. Query |\n");
printf("\t\t | 7. Statistic |\n");
printf("\t\t | 8. Add Records from a Text File|\n");
printf("\t\t | 9. Write to a Text file |\n");
printf("\t\t | 0. Quit |\n");
printf("\t\t*****************************************\n");
printf("\t\t\tGive your Choice(0-9):");
c=getchar(); /*读入选择*/
}while(c<'0'||c>'9');
return(c-'0'); /*返回选择*/
}
int Input(Student stud[],int n) /*输入若干条记录*/
{int i=0;
char sign,x[10]; /*x[10]为清除多余的数据所用*/
while(sign!='n'&&sign!='N') /*判断*/
{ printf("\t\t\tstudent's num:"); /*交互输入*/
scanf("\t\t\t%s",stud[n+i].num);
printf("\t\t\tstudent's name:");
scanf("\t\t\t%s",stud[n+i].name);
printf("\t\t\tstudent's score:");
scanf("\t\t\t%d",&stud[n+i].score);
gets(x); /*清除多余的输入*/
printf("\t\t\tany more records?(Y/N)");
scanf("\t\t\t%c",&sign); /*输入判断*/
i++;
}
return(n+i);
}
void Display(Student stud[],int n) /*显示所有记录*/
{
int i;
printf("\t\t\t-----------------------------------\n"); /*格式头*/
printf("\t\t\tnumber name score\n");
printf("\t\t\t-----------------------------------\n");
for(i=1;i<n+1;i++) /*循环输入*/
{
printf("\t\t\t%-16s%-15s%d\n",stud[i-1].num,stud[i-1].name,stud[i-1].score);
if(i>1&&i%10==0) /*每十个暂停*/
{printf("\t\t\t-----------------------------------\n"); /*格式*/
printf("\t\t\t");
system("pause");
printf("\t\t\t-----------------------------------\n");
}
}
printf("\t\t\t");
system("pause");
}
void Sort_by_num(Student stud[],int n) /*按学号排序*/
{ int i,j,*p,*q,s;
char t[10];
for(i=0;i<n-1;i++) /*冒泡法排序*/
for(j=0;j<n-1-i;j++)
if(strcmp(stud[j].num,stud[j+1].num)>0)
{strcpy(t,stud[j+1].num);
strcpy(stud[j+1].num,stud[j].num);
strcpy(stud[j].num,t);
strcpy(t,stud[j+1].name);
strcpy(stud[j+1].name,stud[j].name);
strcpy(stud[j].name,t);
p=&stud[j+1].score;
q=&stud[j].score;
s=*p;
*p=*q;
*q=s;
}
}
int Insert_a_record(Student stud[],int n) /*插入一条记录*/
{char x[10]; /*清除多余输入所用*/
printf("\t\t\tstudent's num:"); /*交互式输入*/
scanf("\t\t\t%s",stud[n].num);
printf("\t\t\tstudent's name:");
scanf("\t\t\t%s",stud[n].name);
printf("\t\t\tstudent's score:");
scanf("\t\t\t%d",&stud[n].score);
gets(x);
n++;
Sort_by_num(stud,n); /*调用排序函数*/
printf("\t\t\tInsert Successed!\n"); /*返回成功信息*/
return(n);
}
int Delete_a_record(Student stud[],int n) /*按姓名查找，删除一条记录*/
{ char s[20];
int i=0,j;
printf("\t\t\ttell me his(her) name:"); /*交互式问寻*/
scanf("%s",s);
while(strcmp(stud[i].name,s)!=0&&i<n) i++; /*查找判断*/
if(i==n)
{ printf("\t\t\tnot find!\n"); /*返回失败信息*/
return(n);
}
for(j=i;j<n-1;j++) /*删除操作*/
{
strcpy(stud[j].num,stud[j+1].num);
strcpy(stud[j].name,stud[j+1].name);
stud[j].score=stud[j+1].score;
}
printf("\t\t\tDelete Successed!\n"); /*返回成功信息*/
return(n-1);
}
void Query_a_record(Student stud[],int n) /*查找并显示一个记录*/
{ char s[20];
int i=0;
printf("\t\t\tinput his(her) name:"); /*交互式输入*/
scanf("\t\t\t%s",s);
while(strcmp(stud[i].name,s)!=0&&i<n) i++; /*查找判断*/
if(i==n)
{ printf("\t\t\tnot find!\n"); /*输入失败信息*/
return;

}
printf("\t\t\this(her) number:%s\n",stud[i].num); /*输出该学生信息*/
printf("\t\t\this(her) score:%d\n",stud[i].score);
}
void Statistic(Student stud[],int n) /*新增功能，输出统计信息*/
{ int i,j=0,k=0,sum=0;
float aver; /*成绩平均值*/
for(i=0;i<n;i++) /*循环输入判断*/
{
sum+=stud[i].score;
if(stud[j].score>stud[i].score) j=i;
if(stud[k].score<stud[i].score) k=i;
}
aver=1.0*sum/n;
printf("\t\t\tthere are %d records.\n",n); /*总共记录数*/
printf("\t\t\tthe hignest score:\n"); /*最高分*/
printf("\t\t\tnumber:%s name:%s score:%d\n",stud[j].num,stud[j].name,stud[j].score);
printf("\t\t\tthe lowest score:\n"); /*最低分*/
printf("\t\t\tnumber:%s name:%s score:%d\n",stud[k].num,stud[k].name,stud[k].score);
printf("\t\t\tthe average score is %5.2f\n",aver); /*平均分*/
}
int AddfromText(Student stud[],int n) /*从文件中读入数据*/
{ int i=0,num;
FILE *fp; /*定义文件指针*/
char filename[20]; /*定义文件名*/
printf("\t\t\tInput the filename:");
scanf("\t\t\t%s",filename); /*输入文件名*/
if((fp=fopen(filename,"rb"))==NULL) /*打开文件*/
{ printf("\t\t\tcann't open the file\n"); /*打开失败信息*/
printf("\t\t\t");
system("pause");
return(n);
}
fscanf(fp,"%d",&num); /*读入总记录量*/
while(i<num) /*循环读入数据*/
{
fscanf(fp,"%s%s%d",stud[n+i].num,stud[n+i].name,&stud[n+i].score);
i++;
}
n+=num;
fclose(fp); /*关闭文件*/
printf("\t\t\tSuccessed!\n");
printf("\t\t\t");
system("pause");
return(n);
}
void WritetoText(Student stud[],int n) /*将所有记录写入文件*/
{
int i=0;
FILE *fp; /*定义文件指针*/
char filename[20]; /*定义文件名*/
printf("\t\t\tWrite Records to a Text File\n"); /*输入文件名*/
printf("\t\t\tInput the filename:");
scanf("\t\t\t%s",filename);
if((fp=fopen(filename,"w"))==NULL) /*打开文件*/
{
printf("\t\t\tcann't open the file\n");
system("pause");
return;
}
fprintf(fp,"%d\n",n); /*循环写入数据*/
while(i<n)
{
fprintf(fp,"%-16s%-15s%d\n",stud[i].num,stud[i].name,stud[i].score);
i++;
}
fclose(fp); /*关闭文件*/
printf("Successed!\n"); /*返回成功信息*/
}
void main() /*主函数*/
{
int n=0;
for(;;)
{
switch(menu_select()) /*选择判断*/
{
case 1:
printf("\t\t\tInput Records\n"); /*输入若干条记录*/
n=Input(stu,n);
break;
case 2:
printf("\t\t\tDisplay All Records\n"); /*显示所有记录*/
Display(stu,n);
break;
case 3:
printf("\t\t\tSort\n");
Sort_by_num(stu,n); /*按学号排序*/
printf("\t\t\tSort Suceessed!\n");
printf("\t\t\t");
system("pause");
break;
case 4:
printf("\t\t\tInsert a Record\n");
n=Insert_a_record(stu,n); /*插入一条记录*/
printf("\t\t\t");
system("pause");
break;
case 5:
printf("\t\t\tDelete a Record\n");
n=Delete_a_record(stu,n); /*按姓名查找，删除一条记录*/
printf("\t\t\t");
system("pause");
break;
case 6:
printf("\t\t\tQuery\n");
Query_a_record(stu,n); /*查找并显示一个记录*/
printf("\t\t\t");
system("pause");
break;
case 7:
printf("\t\t\tStatistic\n");
Statistic(stu,n); /*新增功能，输出统计信息*/
printf("\t\t\t");
system("pause");
break;
case 8:
printf("\t\t\tAdd Records from a Text File\n");
n=AddfromText(stu,n); /*新增功能，输出统计信息*/
break;
case 9:
printf("\t\t\tWrite to a Text file\n");
WritetoText(stu,n); /*循环写入数据*/
printf("\t\t\t");
system("pause");
break;
case 0:
printf("\t\t\tHave a Good Luck,Bye-bye!\n"); /*结束程序*/
printf("\t\t\t");
system("pause");
exit(0);
}
}
}