小弟新手，请各位高手帮下忙     编一个学生成绩管理系统，
   
  主要功能：
1，能按学期，年纪完成对学生成绩的录入和修改；
2，按班级统计学生成绩，求学生总分及平均分，并且按平均分进行排列；
3，能查询学生成绩，不及格科目及学生名单；
4，能按班级输出学生的成绩单；

    感谢不已！

又是这个课程设计······

是啊！那题目是百考不厌的，小弟不才，接触C语言不久，还请大师多多指教！多谢了！

课程题目是一样的，但主要功能不同了咯......

LZ还是自己动手比较好，不会了可以大家讨论

买本书去 最后都有源代码

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <malloc.h>
struct Record
{
 int ID;
 char name[20];
 char phoneNum[11];
 int team;
};
struct Record Records[300];
int num=0;
void AddNew();
int IsLoop();
void Display();
void ShowMenu();
void Search_name();
void Search_phoneNum();
void Search_team();
void ChkData(char name[],char phoneNum[],int team);
void Record_Modify();
void DeleteMenu();
void DeleteAll();
void DeleteOne();
void ReadFromFile();
void MainMenu();
void WriteToFile();
void main()
{
 ReadFromFile();
 while (1)
 {
  MainMenu();
  WriteToFile();
 }
}


//返回下标
int Record_SearchByName(char name[])
{
     int i;
     for (i=0;i<num;i++)
     {
         if (strcmp(Records[i].name,name)==0)
         {
              return i;
         }
     }
     return -1;
}
//显示一条信息
void Record_DisplaySingle(int index)

{

     printf("\n%s%s%s\n\n","姓名\t","号码\t","组名\t");

     printf("--------------------------------------------------------------------------\n");

     printf("%-6s%5s%7d\n",Records[index].name,Records[index].phoneNum,Records[index].team);
}
//主菜单
void MainMenu()
{
 printf("------------------------主菜单-----------------------------\n");
 int option;
 printf("1-添加新记录\n");
 printf("2-查看\n");
 printf("3-修改\n");
 printf("4-删除\n");
 printf("5-退出程序\n");
 printf("请选择:");
 scanf("%d",&option);
 getchar();
 switch (option)
 {
 case 1:AddNew();break;
 case 2:ShowMenu();break;
 case 3:Record_Modify();break;
 case 4:DeleteMenu();break;
 case 5:exit(0);
 }
}
//添加记录
void AddNew()
{
 printf("------------------------添加新记录-----------------------------\n");
 printf("输入姓名:");
 scanf("%s",&Records[num].name);
 getchar();
 printf("输入电话号码:");
 scanf("%s",&Records[num].phoneNum);
 getchar();
 printf("选择分组(1-家庭 2-朋友 3-其他):");
 scanf("%d",&Records[num].team);
 getchar();
 ChkData(Records[num].name,Records[num].phoneNum,Records[num].team);
 printf("你所输入的是:\n姓名:%s  电话号码:%s  ",Records[num].name,Records[num].phoneNum);
 printf("分组:");
 if (Records[num].team==1)
  printf("家庭");
 if (Records[num].team==2)
  printf("朋友");
 if (Records[num].team==3)
  printf("其他");
 printf("\n是否存储?(Y/N):");
 if (getchar()=='y' || getchar()=='Y')
 {
  num++;
  getchar();
 }
}
//查询菜单
void ShowMenu()
{
 printf("------------------------查询菜单-----------------------------\n");
 int option;
 printf("1-查看所有\n2-按姓名查询\n3-按号码查询\n4-按分组查询\n5-返回主菜单\n请选择:");
 scanf("%d",&option);
 getchar();
 switch (option)
 {
 case 1:
  Display();ShowMenu();
 case 2:
  Search_name();ShowMenu();
 case 3:
  Search_phoneNum();ShowMenu();
 case 4:
  Search_team();ShowMenu();
 case 5:
  MainMenu();
 default:
  ShowMenu();
 }
}
//显示所有信息
void Display()
{
 int i;
 printf("姓名                  电话号码     分组\n--------------------------------------------------------------------------\n");
 for (i=0;i<num;i++)
 {
  printf("%-20s  %-11s",Records[i].name,Records[i].phoneNum);
  if (Records[i].team==1)
   printf("  %-5s\n","家庭");
  if (Records[i].team==2)
   printf("  %-5s\n","朋友");
  if (Records[i].team==3)
   printf("  %-5s\n","其他");
 }
}
//按姓名查找
void Search_name()
{
 printf("------------------------按姓名查找-----------------------------\n");
 char name[20];
 int i;
 printf("请输入姓名:");
 scanf("%s",name);
 if (strlen(name)>20)
 {
  printf("输入的姓名不能超过20个字符!\n");
  getchar();
  ShowMenu();
 }
 printf("姓名                  电话号码     分组\n--------------------------------------------------------------------------\n");
 for (i=0;i<num;i++)
 {
  if (strcmp(Records[i].name,name)==0)
  {
   printf("%-20s  %-11s  ",Records[i].name,Records[i].phoneNum);
   if (Records[i].team==1)
    printf("  %-5s\n","家庭");
   if (Records[i].team==2)
    printf("  %-5s\n","朋友");
   if (Records[i].team==3)
    printf("  %-5s\n","其他");
  }  
 }
}
//按电话号码查找
void Search_phoneNum()
{
 char number[11];
 int i;
 printf("请输入电话号码:");
 scanf("%s",number);
 printf("姓名                  电话号码     分组\n--------------------------------------------------------------------------\n");
 for (i=0;i<num;i++)
 {
  if (strcmp(Records[i].phoneNum,number)==0)
  {
   printf("%-20s  %-11s  ",Records[i].name,Records[i].phoneNum);
   if (Records[i].team==1)
    printf("  %-5s\n","家庭");
   if (Records[i].team==2)
    printf("  %-5s\n","朋友");
   if (Records[i].team==3)
    printf("  %-5s\n","其他");
  }
 }
}
//按分组查找
void Search_team()
{
 int op,i;
 printf("选择分组(1-家庭 2-朋友 3-其他):");
 scanf("%d",&op);
 printf("姓名                  电话号码     分组\n--------------------------------------------------------------------------\n");
 for (i=0;i<num;i++)
 {
  if (Records[i].team==op)
  {
   printf("%-20s  %-11s  ",Records[i].name,Records[i].phoneNum);
   if (Records[i].team==1)
    printf("  %-5s\n","家庭");
   if (Records[i].team==2)
    printf("  %-5s\n","朋友");
   if (Records[i].team==3)
    printf("  %-5s\n","其他");
  }
 }
}
//修改记录
void Record_Modify()
{
      
         char name[20];
         int index;
   printf("--------------------------修改信息----------------------------");
         printf("\n请输入要修改的姓名:");
         scanf("%s",&name);
   if(strlen(name)>20)
 {
  printf("很抱歉!你输入的姓名长度太长了!\n");
      if (IsLoop())
 {
  Record_Modify();
 }
 else
  return;
 }
         getchar();
         index=Record_SearchByName(name);
         if (index==-1)
         {
              printf("\n该姓名不存在!\n");
         }
         else
         {
              printf("你要修改的信息为:\n");
              Record_DisplaySingle(index);
              printf("\n-----------------------------请输入新值--------------------------\n");
     printf("\n请输入姓名:");
              scanf("%s",&Records[index].name);
     if(strlen(Records[index].name)>20)
 {
  printf("很抱歉!你输入的姓名长度太长了!\n");
      if (IsLoop())
 {
  Record_Modify();
 }
 else
  return;
 }
              getchar();
              printf("\n请输入电话号码(7--11位):");
              scanf("%s",&Records[index].phoneNum);
     if(strlen(Records[index].phoneNum)>11||strlen(Records[index].phoneNum)<7)
 {
  printf("很抱歉!你输入的不是合法的电话号码!\n");
      if (IsLoop())
 {
  Record_Modify();
 }
 else
  return;
 }
              getchar();
              printf("\n选择分组(1-家庭 2-朋友 3-其他):");
     scanf("%d",&Records[index].team);
           getchar();
         }
         if (IsLoop())
 {
  Record_Modify();
 }
 else
  return;

}
//数据检测
void ChkData(char name[],char phoneNum[],int team)
{
 if (strlen(name)>20)
 {
  printf("姓名的字符不能超过20个!\n");
  MainMenu();
 }
 if (strlen(phoneNum)>11)
 {
  printf("电话号码不能超过11位!\n");
  MainMenu();
 }
 else
 {
  double phoneNumLen;
  phoneNumLen=strlen(phoneNum);
  for (int i=0;i<phoneNumLen;i++)
  {
   if (isdigit(phoneNum[i])==0)
   {
    printf("电话号码应为数字!\n");
    MainMenu();
   }
  }
 }
 if (team>3 || team<1)
 {
  printf("分组选择错误!\n");
  MainMenu();
 }
}
//删除菜单
void DeleteMenu()
{
 printf("--------------------------删除菜单--------------------------\n");
 printf("1-删除单条信息\n2-删除所有\n3-返回主菜单\n请输入:");
 int op;
 scanf("%d",&op);
 switch (op)
 {
 case 1:
  DeleteOne();break;
 case 2:
  DeleteAll();break;
 case 3:
  MainMenu();break;
 default:
  DeleteMenu();break;
 }
}
//删除所有
void DeleteAll()
{
 printf("是否删除?(Y/N)");
 if (getchar()=='Y' || getchar()=='y')
 {
  printf("***********************删除所有******************\n");
  system("copy none phone.txt");
  printf("\r已经删除\n");
  main();
 }
 else
  return;
}
//删除一条信息
void DeleteOne()
{
    int i;  
         char name[20];
         int index;
         printf("\n请输入要删除的姓名:");
         scanf("%s",&name);
   if(strlen(name)>20)
 {
  printf("很抱歉!你输入的姓名长度太长了!\n");
      if (IsLoop())
 {
  DeleteMenu();
 }
       else
   return;
 }
         getchar();
         index=Record_SearchByName(name);
         if (index==-1)
         {
              printf("\n该姓名不存在!\n");
         }
         else
         {
              printf("\n你要删除的记录为:\n");
              Record_DisplaySingle(index);
              printf("\n是否真的要删除?(y/n)\n");
              char p;
   scanf("\n%c",&p);
         if (p=='Y'||p=='y')
              {
                   for (i=index;i<num-1;i++)
                   {
                       Records[i]=Records[i+1];
                   }
                   num--;
              }
              getchar();
         }
          if (IsLoop())
 {
  DeleteMenu();
 }
 else
  return;
  }
//循环输入
int IsLoop()
{
 printf("是否继续?(Y/N):");
 if (getchar()=='y' || getchar()=='Y')
 {
  return 1;
 }
 else
  return 0;
}
//从文件读取记录
void ReadFromFile()
{
     FILE *fp;
     int i;
     if ((fp=fopen("phone.txt","rb"))==NULL)
     {
   printf("电话簿不存在，已重新建立!\n");
         return;
     }
     if (fread(&num,sizeof(int),1,fp)!=1)
     {
         num=-1;
     }
     else
     {
         for(i=0;i<num;i++)
         {
              fread(&Records[i],sizeof(struct Record),1,fp);
         }
     }
     fclose(fp);
}

//将记录写如文件
void WriteToFile()
{

     FILE *fp;
     int i;
     if ((fp=fopen("phone.txt","wb"))==NULL)
     {
         printf("不能打开文件!\n");
         return;
     }
     if (fwrite(&num,sizeof(int),1,fp)!=1)
     {
         printf("写入文件错误!\n");
     }
     for (i=0;i<num;i++)
     {
         if (fwrite(&Records[i],sizeof(struct Record),1,fp)!=1)
         {
              printf("写入文件错误!\n");
         }
     }     
     fclose(fp);
}
自己该 一 下

多谢了！！！ 很久没来看这贴了。。。呵呵O(∩_∩)O~