这是上个星期老师置的作业，今天完成了，写上来给大家参考下，编译已通过．
如果发现哪有不足的地方请指正．

#include <stdio.h>
#include <string.h>
#include <graphics.h>
#define NUM 100   /*定义最多学生人数*/

/*定义学生数据结构体变量*/

struct std
{ long num;
  char name[20];
  int en_score;
  int math_score;
  int c_score;
  float aver;
  int order;
}data[NUM]={{0,"",0,0,0,0,0}},*pt;

void border();
void item();
int SIZE=0;

/*输入函数：输入学生数据*/

void input()
{
    pt=data;
    gotoxy(0,0);
    printf("Please input student number:");
    scanf("%d",&SIZE);
    for (;pt<data+SIZE;pt++)
    {
scanf("%ld%s%d%d%d",&pt->num,pt->name,&pt->en_score,&pt->math_score,&pt->c_score);
    }
    pt=data;
}

/*输出学生数据*/

void output()
{
    if (SIZE==0)
    {
printf("No Data!\n");
input();
    }
    border();
    item();
    for (;pt<data+SIZE;pt++)
list();
    border();
    pt=data;
}


/*绘制菜单边框*/

void border()
{
    int i,j;
    printf("   %c",179);
    for (i=0;i<6;i++)
putchar('-');
    putchar(179);
    for (i=0;i<20;i++)
putchar('-');
    putchar(179);
    for (i=0;i<5;i++)
    {
for (j=0;j<8;j++)
     putchar('-');
putchar(179);
    }
    printf("   ");
}


/*菜单选项输出*/

void item()
{
    int i;
    printf("   %c%6s%c%20s%c%8s%c%8s%c%8s%c%8s%c%8s%c   ",179,"Number",179,"Name",179,"English",179,"Math",179,"Cprogram",179,"Average",179,"Order",179);
    printf("   %c",179);
    for (i=0;i<72;i++)
printf("%c",'-');
    printf("%c   ",179);
}


/*定位学生函数*/

void locate()
{
    long n;
    printf("please input the student's number");
    scanf("%ld",&n);
    for (;pt<data+SIZE;pt++)
    {
if (n==pt->num)
{
     border();
     item();
     list();
     border();
}
    }
    pt=data;
}

/*输出列表函数*/

int list()
{
    int i;
    printf("   %c%6ld%c%20s%c%8d%c%8d%c%8d%c%8.1f%c%8d%c   ",179,pt->num,179,pt->name,179,pt->en_score,179,pt->math_score,179,pt->c_score,179,pt->aver,179,pt->order,179);
    printf("   %c",179);
    for (i=0;i<72;i++)
printf("%c",'-');
    printf("%c   ",179);
    return 0;
}
int list2(struct std *a)
{
    int i;
    printf("   %c%6ld%c%20s%c%8d%c%8d%c%8d%c%8.1f%c%8d%c   ",179,a->num,179,a->name,179,a->en_score,179,a->math_score,179,a->c_score,179,a->aver,179,a->order,179);
    printf("   %c",179);
    for (i=0;i<72;i++)
printf("%c",'-');
    printf("%c   ",179);
    return 0;
}

/*平均数函数*/

void average()
{
    for (pt=data;pt<data+SIZE;pt++)
pt->aver=(float)(pt->en_score+pt->math_score+pt->c_score)/3;
    printf("\n\n\n\n\n\t\t\tSUCCESS!\n");
    pt=data;
}

/*排序函数*/

void sort()
{
    int i;
    border();
    item();
    for (i=1;i<=SIZE;i++)
for (pt=data;pt<data+SIZE;pt++)
     if (pt->order==i)
     {
  list();
     }
   border();
}
void courseaver()
{
    int i;
    float aver=0;
    border();
    for (i=0;i<SIZE;i++)
    {
aver+=(pt+i)->en_score;
aver/=SIZE;
    }
    printf("   | English  Course  Average   :     %8.1f                              |\n",aver);
    aver=0;
    border();
    for (i=0;i<SIZE;i++)
    {
aver+=(pt+i)->math_score;
aver/=SIZE;
    }
    printf("   | Maths  Course  Average     :     %8.1f                              |\n",aver);
    aver=0;
    border();
    for (i=0;i<SIZE;i++)
    {
aver+=(pt+i)->c_score;
aver/=SIZE;
    }
    printf("   | C Program Course Average   :     %8.1f                              |\n",aver);
    aver=0;
    border();
}

/*出入学生数据*/

void insert()
{
    pt=data;
    printf("Please add a student's data:\n");
    scanf("%ld%s%d%d%d",&(pt+SIZE)->num,(pt+SIZE)->name,&(pt+SIZE)->en_score,&(pt+SIZE)->math_score,&(pt+SIZE)->c_score);
    SIZE=SIZE+1;
}

/*排名*/

void order()
{
    int i,j,k,max[10]={0};
    pt=data;
    for (i=0;i<SIZE;i++)
    {
for (j=i+1;j<SIZE;j++)
{
      for (k=0;k<10;k++)
   if (j==max[k]) break;
      if ( (pt+i)->aver <=(pt+j)->aver )
   max=j;
      else
   max=i;
       }
       (pt+max)->order=i+1;
     }
}


/*删除学生数据*/

void del()
{
    long n,i;
    printf("Please input the student's num to delete:\n");
    scanf("%ld",&n);
    for (;pt<data+SIZE;pt++)
    {
  if(pt->num==n)
  {
      for (i=pt-data;i<SIZE;i++)
      {
    (pt+i)->num=(pt+i+1)->num;
    strcpy((pt+i)->name,(pt+i+1)->name);
    (pt+i)->en_score=(pt+i+1)->en_score;
    (pt+i)->math_score=(pt+i+1)->math_score;
    (pt+i)->c_score=(pt+i+1)->c_score;
    (pt+i)->aver=(pt+i+1)->aver;
    (pt+i)->order=(pt+i+1)->order;
      }
  }
    }
    SIZE=SIZE-1;
    pt=data;
}


/*保存数据*/

void save()
{
    FILE *fp;
    char fname[50];
    int i;
    printf("Please input a filename to save:\n");
    scanf("%s",fname);
    if ((fp=fopen(fname,"wb"))==NULL)
    {
  printf("File creat error!\n");
  quit();
    }
    for (i=0;i<SIZE;i++)
fwrite(pt+i,sizeof(struct std),1,fp);
    fclose(fp);
}


/*编辑学生数据*/

void edit()
{
    long n;
    printf("Please input a student's num to edit:");
    scanf("%ld",&n);
    for (pt=data;pt<data+SIZE;pt++)
    {
  if(pt->num==n)
  {
      scanf("%ld%s%d%d%d",&pt->num,pt->name,&pt->en_score,&pt->math_score,&pt->c_score);
      break;
  }
     }
     pt=data;
}

/*载入学生数据*/

void load()
{
    FILE *fp;
    char fname[50];
    int i,j=0;
    printf("Please input a filename to load:\n");
    scanf("%s",fname);
    if ((fp=fopen(fname,"rb"))==NULL)
    {
  printf("File load error!\n");
  quit();
    }
    for (i=0;i<!feof(fp);i++)
j+=(fread(pt+i,sizeof(struct std),1,fp));
    SIZE=j;
    border();
    item();
    for (i=0;i<j;i++)
{
     list(pt+i);
}
    border();
    fclose(fp);
}


/*绘制菜单*/

void menu()
{
    int i;
    printf("\n\n\n\n\n\t%c",201);
    for (i=0;i<62;i++)
printf("%c",205);
    printf("%c\t",187);
    items();
    printf("\t%c",200);
    for (i=0;i<62;i++)
printf("%c",205);
    printf("%c\t",188);
    printf("\t SIZE=%d.\n",SIZE);
    printf("\t Please input your choice:");
    react();
}

/*退出函数*/

int quit()
{
    char ch;
    printf("\n\n\n\n\n\t\tAre you sure to quit?(Y/N)");
    ch=getchar();
    if (ch=='y' ||ch=='Y')
    {
exit(0);
closegraph();
    }
    else if(ch=='n' ||ch=='N')
    {
clrscr();
menu();
    }
    else
    {
printf("\n\tINVALID INPUT! TYR AGAIN");
clrscr();
quit();
    }
}

/*输出所有菜单选项*/

void choice(char *s)
{
    int i,j;
    printf("\t%c",186);
    for (j=0;j<6;j++)
printf("%c",32);
    printf("%s",s);
    for (j=0;j<(80-18-6-strlen(s));j++)
printf("%c",32);
    printf("%c\t",186);
}
int items()
{
    int i;
    char ch1[51],ch2[51];
    for (i=0;i<50;i++)
    {
ch2='*';
if (i>=23 && i<=26)
     {ch1[23]='M';ch1[24]='E';ch1[25]='N';ch1[26]='U';}
else
     ch1='*';
    }
    ch1[50]='\0';
    ch2[50]='\0';
    choice(ch1);
    choice(" 0.  INPUT data of students");
    choice(" 1.  OUTPUT all data of students");
    choice(" 2.  LOCATE data on NUMBER of students");
    choice(" 3.  Calculate AVERAGE of students");
    choice(" 4.  SORT on AVERAGE of students");
    choice(" 5.  Calculate COURSE AVERAGE of all");
    choice(" 6.  Output AVERAGE total of course");
    choice(" 7.  Fill order of all ");
    choice(" 8.  Insert a record in table");
    choice(" 9.  Delete a record in table");
    choice(" 10. Update records in table");
    choice(" 11. Save student table to a file");
    choice(" 12. Load student table from a file");
    choice(" 13. Edit a student's data");
    choice(" 14. Quit");
    choice(ch2);
    return 0;
}

/*根据不同的选项做出不同的反应*/

int react()
{
    int ch;
    scanf("%d",&ch);
    switch(ch)
    {
case 0:cleardevice();input();system("pause");cleardevice();menu();break;
case 1:cleardevice();output();system("pause");cleardevice();menu();break;
case 2:cleardevice();locate();system("pause");cleardevice();menu();break;
case 3:cleardevice();average();system("pause");cleardevice();menu();break;
case 4:cleardevice();sort();system("pause");cleardevice();menu();break;
case 5:cleardevice();courseaver();system("pause");cleardevice();menu();break;
case 6:cleardevice();output();system("pause");cleardevice();menu();break;
case 7:cleardevice();order();system("pause");cleardevice();menu();break;
case 8:cleardevice();insert();system("pause");cleardevice();menu();break;
case 9:cleardevice();del();system("pause");cleardevice();menu();break;
case 10:cleardevice();printf("\n\n\n\n\n\tUpdate Success!\n");system("pause");cleardevice();menu();break;
case 11:cleardevice();save();system("pause");cleardevice();menu();break;
case 12:cleardevice();load();system("pause");cleardevice();menu();break;
case 13:cleardevice();edit();system("pause");cleardevice();menu();break;
case 14:cleardevice();quit();system("pause");cleardevice();menu();break;
default:printf("\t Invalid Choice!Try Again:");react();
    }
}

/*主函数*/

main()
{
    int gd=DETECT,gm;
    initgraph(&gd,&gm,"D:\\TURBOC2\\");
    menu();
    return 0;
}



本程序还要一些不完善的地方，有兴趣的朋友可以看看。