cpp文件需要与名为‘class.txt’,'student.txt','score.txt'三个文件放在一个文件夹才能正常运行，如图：

 代码如下:

//使用此程序时需将源程序整个文件夹拖到桌面才可使用 

#include <stdio.h>
#include <stdlib.h>
#include<string.h>
#include<process.h>
#include<conio.h>
#define OK 1
#define ERROR 0
#define OVERFLOW -2
#define MAXSIZE 100
#include <iomanip>
#include <iostream>
using namespace std;

typedef struct
{
	int num;
	char name[10];
	float score;
	char teacher[10];
}Cls;

typedef struct
{
	Cls *elem;
	int length;
}Class;

typedef struct 
{
	int num;
	char name[10];
	char clas[10];
	char birth[10];
	long long QQ;
}Std1;

typedef int Status;
typedef Std1 ElemType;

typedef struct
{
	ElemType *elem;
	int length;
}Std;

typedef struct
{
	int snum;
	int cnum;
	float score;
	int trem;
}Sco;

typedef struct
{
	Sco *elem;
	int length;
}Score;

Status menu();
Status ReadStu( Std &stu );
Status ReadCls( Class &cls );
Status ReadSco( Score &sco );
Status InitList( Std &stu );
Status InitList( Class &cls );
Status InitList( Score &sco );
Status InputStd( Std &stu );
Status InputClass( Class &cls );
Status InputScore( Score &sco );
Status InputMenu( Std &stu, Class &cls, Score &sco );
Status OutputStd( Std &stu );
Status OutputCls( Class &cls );
Status OutputSco( Score &sco );
Status OutputMenu( Std &stu, Class &cls, Score &sco );
Status SearchStd( Std &stu );
Status SearchCls( Class &cls );
Status SearchSco( Score &sco );
Status SearchMenu( Std &stu, Class &cls, Score &sco );
Status ModifyStd( Std &stu );
Status ModifyCls( Class &cls );
Status ModifySco( Score &sco );
Status ModifyMenu( Std &stu, Class &cls, Score &sco );
Status DeleteStd( Std &stu );
Status DeleteCls( Class &cls );
Status DeleteSco( Score &sco );
Status DeleteMenu( Std &stu, Class &cls, Score &sco );
Status SaveStd( Std &stu );
Status SaveCls( Class &cls );
Status SaveSco( Score &sco );
Status SaveMenu( Std &stu, Class &cls, Score &sco );
Status SearchOsco( Score &sco , Class &cls , Std &stu );
Status SearchCSco( Std &stu, Class &cls, Score &sco );
Status Searchlsco( Std &stu, Class &cls, Score &sco, char *clas );

int main()  
{
	int i;
	Std stu;
	Class cls;
	Score sco;
	char *clas;
	InitList( stu );
	InitList( cls );
	InitList( sco );
	ReadStu( stu );
	ReadCls( cls );
	ReadSco( sco );
	short int flag = 0; 
	menu();
	do
	{ 
		flag=1;    
		switch( getch() )    
		{ 
			case '1' :
				InputMenu( stu, cls, sco );//添加信息 
				break;
			case '2' :
				OutputMenu( stu, cls, sco );//输出信息 
				break;
			case '3' :
				SearchMenu( stu, cls, sco );//查询信息 
				break;
			case '4' :
				ModifyMenu( stu, cls, sco );//修改成绩 
				break;
			case '5' :
				DeleteMenu( stu, cls, sco );//删除信息 
				break;
			case '6' :
				SearchOsco( sco , cls , stu );//查询个人成绩 
				break;
			case '7' :
				SearchCSco( stu, cls, sco ); //查询某门课程所有成绩 
				break;
			case '8' :
				Searchlsco( stu, cls, sco ,clas );//查询某班级某门课所有成绩 
				break;
			case '9' :
				SaveMenu( stu, cls, sco );  //保存信息 
				break;
			case '0' :
				cout<<"已成功退出，欢迎您下次使用^-^"<<endl;
				exit( 0 );    
			default : 
				cout<<"输入有误"<<endl;
		}
		cout<<"按任意键继续"<<endl;
		getch();
		menu();
	}
	while( flag == 1 );
}

Status menu()
{   
	system("cls");  
	cout<<endl;  
	cout<<"*********欢迎进入学生成绩管理系统**************"<<endl;
	cout<<"                 菜单                          "<<endl;
	cout<<"录入信息-------------------------------------1"<<endl;
	cout<<"输出信息-------------------------------------2"<<endl;
	cout<<"查询信息-------------------------------------3"<<endl;
	cout<<"修改信息-------------------------------------4"<<endl;
	cout<<"删除信息-------------------------------------5"<<endl;
	cout<<"查询个人成绩---------------------------------6"<<endl;
	cout<<"查询某门课程所有人成绩-----------------------7"<<endl;
	cout<<"查询某班级某门课所有成绩---------------------8"<<endl;
	cout<<"保存信息-------------------------------------9"<<endl;
	cout<<"退出系统-------------------------------------0"<<endl;
	cout<<"**********************************************"<<endl;
	cout<<"请输入您的选择"<<endl;
}

Status ReadStu( Std &stu )
{
	FILE *fp;
	int i;
	if( ( fp = fopen( "student.txt" , "r" ) ) == NULL )
	{
		cout<<"打开失败!"<<endl;
		return ERROR;
		exit( 0 );
	}
	for( i = 0; !feof(fp); i++ )
	{
		fscanf( fp ,"%d %s %s %s %lld", &stu.elem[i].num, &stu.elem[i].name, &stu.elem[i].clas
		, &stu.elem[i].birth, &stu.elem[i].QQ );
		++stu.length;
	}
	fclose( fp );
	stu.length--;
	return OK;
}

Status ReadCls( Class &cls )
{
	FILE *fp;
	int i;
	if( ( fp = fopen( "class.txt" , "r" ) ) == NULL )
	{
		cout<<"打开失败!"<<endl;
		return ERROR;
		exit( 0 );
	}
	for( i = 0; !feof(fp); i++ )
	{
		fscanf( fp ,"%d %s %f %s", &cls.elem[i].num, &cls.elem[i].name
		, &cls.elem[i].score, &cls.elem[i].teacher );
		++cls.length;
	}
	fclose( fp );
	cls.length--;
	return OK;
}

Status ReadSco( Score &sco )
{
	FILE *fp;
	int i;
	if( ( fp = fopen( "score.txt" , "r" ) ) == NULL )
	{
		cout<<"打开失败!"<<endl;
		return ERROR;
		exit( 0 );
	}
	for( i = 0; !feof(fp); i++ )
	{
		fscanf( fp ,"%d %d %f %d", &sco.elem[i].snum, &sco.elem[i].cnum
		, &sco.elem[i].score, &sco.elem[i].trem );
		++sco.length;
	}
	fclose( fp );
	sco.length--;
	return OK;
}

Status InitList( Std &stu )
{
	stu.elem = new ElemType[MAXSIZE];
	if( !stu.elem )
	exit( OVERFLOW );
	stu.length = 0;
	return OK;
}

Status InitList( Class &cls )
{
	cls.elem = new Cls[MAXSIZE];
	if( !cls.elem )
	exit( OVERFLOW );
	cls.length = 0;
	return OK;
}

Status InitList( Score &sco )
{
	sco.elem = new Sco[MAXSIZE];
	if( !sco.elem )
	exit( OVERFLOW );
	sco.length = 0;
	return OK;
}

Status InputStd( Std &stu )
{
	int i, n, k, a = 0;
	cout<<"请输入学生总数:"<<endl;
	if( cin>>n && n > 0 )
	{
		for( i = 0; i < n ; i++ )
		{
			cout<<"请输入学生"<<i+1<<"的学号"<<endl;
			cin>>stu.elem[stu.length].num;
			for( k = 0; k < stu.length; k++ )
			{
				if( stu.elem[k].num == stu.elem[stu.length].num )
				{
					cout<<"学号重复，已有该学生！"<<endl;
					a = 1;
					break;
				}	
			}
			if( a == 1 )
				break;
			cout<<"请输入学生"<<i+1<<"的姓名"<<endl;
			cin>>stu.elem[stu.length].name;
			cout<<"请输入学生"<<i+1<<"的班级"<<endl;
			cin>>stu.elem[stu.length].clas;
			cout<<"请输入学生"<<i+1<<"的出生日期"<<endl;
			cin>>stu.elem[stu.length].birth;
			cout<<"请输入学生"<<i+1<<"的QQ"<<endl;
			cin>>stu.elem[stu.length].QQ;
			++stu.length;
		}
	}
}

Status InputClass( Class &cls )
{
	int i, n, k ,a;
	cout<<"请输入课程总数："<<endl;
	if( cin>>n && n > 0 )
	{
		for( i = 0; i < n; i++ )
		{
			cout<<"请输入课程"<<i+1<<"的课程号"<<endl;
			cin>>cls.elem[cls.length].num;
			for( k = 0; k < cls.length; k++ )
			{
				if( cls.elem[k].num == cls.elem[cls.length].num )
				{
					cout<<"课程号重复，已有该课程！"<<endl;
					a = 1;
					break;
				}
			}
			if( a == 1 )
				break;
			cout<<"请输入课程"<<i+1<<"的课程名"<<endl;
			cin>>cls.elem[cls.length].name;
			cout<<"请输入课程"<<i+1<<"的学分"<<endl;
			cin>>cls.elem[cls.length].score;
			cout<<"请输入课程"<<i+1<<"的任课教师"<<endl;
			cin>>cls.elem[cls.length].teacher;
			++cls.length;
		}
	}
	
}

Status InputScore( Score &sco )
{
	int i, n, a, b, k;
	cout<<"请输入录入成绩总数:"<<endl;
	if( cin>>n && n > 0 )
	{
		for( i = 0; i < n; i++ )
		{
			cout<<"请输入学号"<<endl;
			cin>>sco.elem[sco.length].snum;
			cout<<"请输入课程号"<<endl;
			cin>>sco.elem[sco.length].cnum;
			for( k = 0; k < sco.length; k++ )
			{
				if( sco.elem[k].cnum == sco.elem[sco.length].cnum 
				&& sco.elem[k].snum == sco.elem[sco.length].snum )
				{
					cout<<"学号和课程号重复，该学生在该课程上已有成绩！"<<endl;
					a = 1;
					break;
				}
			}
			if( a == 1 )
				break;
			cout<<"请输入分数"<<endl;
			cin>>sco.elem[sco.length].score;
			cout<<"请输入学期数"<<endl;
			cin>>sco.elem[sco.length].trem;
			++sco.length;
		}
	}
}

Status InputMenu(Std &stu,Class &cls, Score &sco )
{
	int i;
	cout<<endl;
	cout<<"1.录入学生信息     || 2.录入课程信息    "<<endl;
	cout<<"3.录入成绩信息     || 4.取消            "<<endl;
	cout<<"请输入你的选择："<<endl;
	cin>>i;
	switch( i )
	{
		case 1:
			InputStd( stu );
			break;
		case 2:
			InputClass( cls );
			break;
		case 3:
			InputScore( sco );
			break;
		case 4:
			cout<<"取消成功！"<<endl;
			break;
		default :
			cout<<"输入有误"<<endl;
			break; 
	}	
	return OK;
}

Status OutputStd( Std &stu )
{
	int i;
	cout<<"学号        姓名        班级        生日        QQ    "<<endl;
	for( i = 0; i < stu.length; i++ )
	{
		cout<<std::left<<setw(12)<<stu.elem[i].num<<std::left<<setw(12)<<stu.elem[i].name
		<<std::left<<setw(12)<<stu.elem[i].clas<<std::left<<setw(12)<<stu.elem[i].birth
		<<std::left<<setw(12)<<stu.elem[i].QQ<<endl;
	}
	return OK;
}

Status OutputCls( Class &cls )
{
	int i;
	cout<<"课程号      课程名      学分        任课教师    "<<endl;
	for( i = 0; i < cls.length ; i++ )
	{
		cout<<std::left<<setw(12)<<cls.elem[i].num<<std::left<<setw(12)
		<<cls.elem[i].name<<std::left<<setw(12)<<cls.elem[i].score
		<<std::left<<setw(12)<<cls.elem[i].teacher<<endl;
	}
	return OK;
}

Status OutputSco( Score &sco )
{
	int i;
	cout<<"学号        课程号      分数        学期数     "<<endl;
	for( i = 0; i < sco.length; i++ )
	{
		cout<<std::left<<setw(12)<<sco.elem[i].snum<<std::left<<setw(12)
		<<sco.elem[i].cnum<<std::left<<setw(12)<<sco.elem[i].score
		<<std::left<<setw(12)<<sco.elem[i].trem<<endl;
	}
	return OK;
}

Status OutputMenu( Std &stu, Class &cls, Score &sco )
{
	int i;
	cout<<endl;
	cout<<"1.查看学生信息     || 2.查看课程信息    "<<endl;
	cout<<"3.查看成绩信息     || 4.取消            "<<endl;
	cout<<"请输入你的选择："<<endl;
	cin>>i;
	switch( i )
	{
		case 1:
			OutputStd( stu );
			break;
		case 2:
			OutputCls( cls );
			break;
		case 3:
			OutputSco( sco );
			break;
		case 4:
			cout<<"取消成功！"<<endl;
			break;
		default :
			cout<<"输入有误"<<endl;
			break; 
	}	
	return OK;
}

Status SearchStd( Std &stu )
{
	int i, n;
	cout<<"请输入要查找的学生的学号"<<endl;
	cin>>n;
	for( i = 0; i < stu.length; i++ )
	{
		if( stu.elem[i].num == n)
		{
			cout<<"查找到学号:"<<n<<"的学生的信息为:"<<endl;
			cout<<"学号        姓名        班级        生日        QQ    "<<endl;
			cout<<std::left<<setw(12)<<stu.elem[i].num<<std::left<<setw(12)<<stu.elem[i].name
			<<std::left<<setw(12)<<stu.elem[i].clas<<std::left<<setw(12)<<stu.elem[i].birth
			<<std::left<<setw(12)<<stu.elem[i].QQ<<endl;
		return OK;
		}
	}
	cout<<"未查找到此学生，请输入正确的学号!"<<endl;
	return ERROR;
}

Status SearchCls( Class &cls )
{
	int i, n;
	cout<<"请输入要查找的课程的课程号:"<<endl;
	cin>>n;
	for( i = 0; i < cls.length; i++ )
	{
		if( cls.elem[i].num == n )
		{
			cout<<"查找到课程号为"<<n<<"的课程信息为："<<endl;
			cout<<"课程号      课程名      学分        任课教师    "<<endl;
			cout<<std::left<<setw(12)<<cls.elem[i].num<<std::left<<setw(12)
			<<cls.elem[i].name<<std::left<<setw(12)<<cls.elem[i].score
			<<std::left<<setw(12)<<cls.elem[i].teacher<<endl;
			return OK;
		}
	}
	cout<<"未查找到此课程，请输入正确的课程号！"<<endl;
	return ERROR;
}

Status SearchSco( Score &sco )
{
	int i, m, n, a;
	cout<<"请分别输入学号和课程号："<<endl; 
	cin>>m>>n;
	for( i = 0; i < sco.length; i++ )
	{
		if( sco.elem[i].snum == m )
		{
			for( a = 0; a < sco.length; a++ )
			{
				if( sco.elem[i].cnum == n )
				{
					cout<<"查找到成绩为："<<endl;
					cout<<"学号        课程号      分数        学期数     "<<endl;
					cout<<std::left<<setw(12)<<sco.elem[i].snum<<std::left<<setw(12)
					<<sco.elem[i].cnum<<std::left<<setw(12)<<sco.elem[i].score
					<<std::left<<setw(12)<<sco.elem[i].trem<<endl;
					return OK;
				}
			}
		}
	}
	cout<<"未查找到此成绩，请输入正确的学号和课程号!"<<endl;
		return ERROR;
}

Status SearchMenu( Std &stu, Class &cls, Score &sco )
{
	int i;
	cout<<endl;
	cout<<"1.查询学生信息     || 2.查询课程信息    "<<endl;
	cout<<"3.查询成绩信息     || 4.取消            "<<endl;
	cout<<"请输入你的选择："<<endl;
	cin>>i;
	switch( i )
	{
		case 1:
			SearchStd( stu );
			break;
		case 2:
			SearchCls( cls );
			break;
		case 3:
			SearchSco( sco );
			break;
		case 4:
			cout<<"取消成功！"<<endl;
			break;
		default :
			cout<<"输入有误"<<endl;
			break; 
	}	
	return OK;
}

Status ModifyStd( Std &stu )
{
	int n, i;
	cout<<"请输入学生的学号"<<endl;
	cin>>n;
	for( i = 0; i < stu.length; i++ )
	{
		if( stu.elem[i].num == n )
		{
			cout<<"查找到学号为"<<n<<"的学生信息为;"<<endl;
			cout<<"学号        姓名        班级        生日        QQ    "<<endl;
			cout<<std::left<<setw(12)<<stu.elem[i].num<<std::left<<setw(12)<<stu.elem[i].name
			<<std::left<<setw(12)<<stu.elem[i].clas<<std::left<<setw(12)<<stu.elem[i].birth
			<<std::left<<setw(12)<<stu.elem[i].QQ<<endl;
			cout<<"请重新输入该学生的信息"<<endl;
			cout<<"学号        姓名        班级        生日        QQ    "<<endl;
			cin>>stu.elem[i].num>>stu.elem[i].name>>stu.elem[i].clas
			>>stu.elem[i].birth>>stu.elem[i].QQ;
			cout<<"修改成功!"<<endl; 
			return OK;
		}
		cout<<"未查找到此学生，请输入正确的学号！"<<endl;
		return ERROR;
	}
}

Status ModifyCls( Class &cls )
{
	int n, i;
	cout<<"请输入课程的课程号"<<endl;
	cin>>n;
	for( i = 0; i < cls.length; i++ )
	{
		if( cls.elem[i].num == n )
		{
			cout<<"查找到课程号为"<<n<<"的课程信息为;"<<endl;
			cout<<"课程号      课程名      学分        任课教师    "<<endl;
			cout<<std::left<<setw(12)<<cls.elem[i].num<<std::left<<setw(12)
			<<cls.elem[i].name<<std::left<<setw(12)<<cls.elem[i].score
			<<std::left<<setw(12)<<cls.elem[i].teacher<<endl;
			cout<<"请重新输入该课程的信息"<<endl;
			cout<<"课程号      课程名      学分        任课教师    "<<endl;
			cin>>cls.elem[i].num>>cls.elem[i].name>>cls.elem[i].score
			>>cls.elem[i].teacher;
			cout<<"修改成功!"<<endl; 
			return OK;
		}
		cout<<"未查找到此课程，请输入正确的课程号！"<<endl;
		return ERROR;
	}
}

Status ModifySco( Score &sco )
{
	int n, m, i, a;
	cout<<"请输入学生的学号和课程号"<<endl;
	cin>>m>>n;
	for( i = 0; i < sco.length; i++ )
	{
		if( sco.elem[i].snum == m )
		{
			for( a = 0; a < sco.length; a++ )
			{
				if( sco.elem[i].cnum == n )
				{
					cout<<"查找到成绩为："<<endl;
					cout<<"学号        课程号      分数        学期数     "<<endl;
					cout<<std::left<<setw(12)<<sco.elem[i].snum<<std::left<<setw(12)
					<<sco.elem[i].cnum<<std::left<<setw(12)<<sco.elem[i].score
					<<std::left<<setw(12)<<sco.elem[i].trem<<endl;
					cout<<"请重新输入成绩信息"<<endl;
					cout<<"学号        课程号      分数        学期数     "<<endl;
					cin>>sco.elem[i].snum>>sco.elem[i].cnum
					>>sco.elem[i].score>>sco.elem[i].trem;
					cout<<"修改成功!"<<endl; 
					return OK;
					
				}
			}
		}
	}
	cout<<"未查找到此成绩，请输入正确的学号和课程号！"<<endl;
	return ERROR;
}

Status ModifyMenu( Std &stu, Class &cls, Score &sco )
{
	int i;
	cout<<endl;
	cout<<"1.修改学生信息     || 2.修改课程信息    "<<endl;
	cout<<"3.修改成绩信息     || 4.取消            "<<endl;
	cout<<"请输入你的选择："<<endl;
	cin>>i;
	switch( i )
	{
		case 1:
			ModifyStd( stu );
			break;
		case 2:
			ModifyCls( cls );
			break;
		case 3:
			ModifySco( sco );
			break;
		case 4:
			cout<<"取消成功！"<<endl;
			break;
		default :
			cout<<"输入有误"<<endl;
			break; 
	}	
	return OK;
}

Status DeleteStd( Std &stu )
{
	int i, n, a;
	char choice;
	cout<<"请输入要删除的学生的学号:"<<endl;
	cin>>n;
	for( i = 0; i < stu.length; i++ )
	{
		if( stu.elem[i].num == n )
		{
			cout<<"查找到学号为"<<n<<"的学生信息为:"<<endl;
			cout<<"学号        姓名        班级        生日        QQ    "<<endl;
			cout<<std::left<<setw(12)<<stu.elem[i].num<<std::left<<setw(12)<<stu.elem[i].name
			<<std::left<<setw(12)<<stu.elem[i].clas<<std::left<<setw(12)<<stu.elem[i].birth
			<<std::left<<setw(12)<<stu.elem[i].QQ<<endl;
			cout<<"确定要删除该学生的信息吗?（y/n）"<<endl;
			cin>>choice;
			if( choice == 'y' )
			{
				for( a = i; a < stu.length; a++ )
				{
					stu.elem[a].num = stu.elem[a+1].num;
					strcpy( stu.elem[a].name, stu.elem[a+1].name ); 
					strcpy( stu.elem[a].clas, stu.elem[a+1].clas );
					strcpy( stu.elem[a].birth, stu.elem[a+1].birth );
					stu.elem[a].QQ = stu.elem[a+1].QQ;
				}
				stu.length--;
				cout<<"已成功删除"<<endl;
				return OK;
			}
			else if( choice =='n' )
			{
				cout<<"您取消了删除"<<endl;
				return OK;
			}
			else
			{
				cout<<"请输入正确的选项！"<<endl;
				return ERROR;
			}
			
		}
		cout<<"未查找到此学生，请输入正确的学号！"<<endl;
		return ERROR;
	}
}

Status DeleteCls( Class &cls )
{
	int i, n, a;
	char choice;
	cout<<"请输入要删除课程的课程号:"<<endl;
	cin>>n;
	for( i = 0; i < cls.length; i++ )
	{
		if( cls.elem[i].num == n )
		{
			cout<<"查找到课程号为"<<n<<"的课程信息为:"<<endl;
			cout<<"课程号      课程名      学分        任课教师    "<<endl;
			cout<<std::left<<setw(12)<<cls.elem[i].num<<std::left<<setw(12)
			<<cls.elem[i].name<<std::left<<setw(12)<<cls.elem[i].score
			<<std::left<<setw(12)<<cls.elem[i].teacher<<endl;
			cout<<"确定要删除该课程的信息吗?（y/n）"<<endl;
			cin>>choice;
			if( choice == 'y' )
			{
				for( a = i; a < cls.length; a++ )
				{
					cls.elem[a].num = cls.elem[a+1].num;
					strcpy( cls.elem[a].name, cls.elem[a+1].name ); 
					strcpy( cls.elem[a].teacher, cls.elem[a+1].teacher );
					cls.elem[a].score = cls.elem[a+1].score;
				}
				cls.length--;
				cout<<"已成功删除"<<endl;
				return OK;
			}
			else if( choice =='n' )
			{
				cout<<"您取消了删除"<<endl;
				return OK;
			}
			else
			{
				cout<<"请输入正确的选项！"<<endl;
				return ERROR;
			}
			
		}
		cout<<"未查找到此课程，请输入正确的课程号！"<<endl;
		return ERROR;
	}
}

Status DeleteSco( Score &sco )
{
	int i, n, m, a;
	char choice;
	cout<<"请分别输入学号和课程号："<<endl; 
	cin>>m>>n;
	for( i = 0; i < sco.length; i++ )
	{
		if( sco.elem[i].snum == m )
		{
			for( a = 0; a < sco.length; a++ )
			{
				if( sco.elem[i].cnum == n )
				{
					cout<<"查找到成绩为："<<endl;
					cout<<"学号        课程号      分数        学期数     "<<endl;
					cout<<std::left<<setw(12)<<sco.elem[i].snum<<std::left<<setw(12)
					<<sco.elem[i].cnum<<std::left<<setw(12)<<sco.elem[i].score
					<<std::left<<setw(12)<<sco.elem[i].trem<<endl;
					cout<<"确定要删除该成绩信息吗?（y/n）"<<endl;
					cin>>choice;
					if( choice == 'y' )
					{
						for( a = i; a < sco.length; a++ )
						{
							sco.elem[a].snum = sco.elem[a+1].snum;
							sco.elem[a].cnum = sco.elem[a+1].cnum;
							sco.elem[a].score = sco.elem[a+1].score;
							sco.elem[a].trem = sco.elem[a+1].trem;
						}
						sco.length--;
						cout<<"已成功删除"<<endl;
						return OK;
					}
					else if( choice =='n' )
					{
						cout<<"您取消了删除"<<endl;
						return OK;
					}
					else
					{
						cout<<"请输入正确的选项！"<<endl;
						return ERROR;
					}
				}
			}
		}
	}
	cout<<"未查找到此成绩，请输入正确的学号!"<<endl;
	return ERROR;
}

Status DeleteMenu( Std &stu, Class &cls, Score &sco )
{
	int i;
	cout<<endl;
	cout<<"1.删除学生信息     || 2.删除课程信息    "<<endl;
	cout<<"3.删除成绩信息     || 4.取消            "<<endl;
	cout<<"请输入你的选择："<<endl;
	cin>>i;
	switch( i )
	{
		case 1:
			DeleteStd( stu );
			break;
		case 2:
			DeleteCls( cls );
			break;
		case 3:
			DeleteSco( sco );
			break;
		case 4:
			cout<<"取消成功！"<<endl;
			break;
		default :
			cout<<"输入有误"<<endl;
			break; 
	}	
	return OK;
}

Status SaveStd( Std &stu )
{
	FILE *fp;
	int i;
	fp = fopen( "student.txt","w" );
	for( i = 0; i< stu.length; i++ )
	{
		fprintf( fp, "%-12d%-12s%-12s%-12s%-12d\n", stu.elem[i].num, stu.elem[i].name
		, stu.elem[i].clas, stu.elem[i].birth, stu.elem[i].QQ );
	}
	fclose(fp);
	return OK;
}

Status SaveCls( Class &cls )
{
	FILE *fp;
	int i;
	fp = fopen( "class.txt","w" );
	for( i = 0; i< cls.length; i++ )
	{
		fprintf( fp, "%-12d%-16s%-12f%-12s%\n",cls.elem[i].num, cls.elem[i].name
		,cls.elem[i].score, cls.elem[i].teacher );
	}
	fclose(fp);
	return OK;
}

Status SaveSco( Score &sco )
{
	FILE *fp;
	int i;
	fp = fopen( "score.txt","w" );
	for( i = 0; i< sco.length; i++ )
	{
		fprintf( fp, "%-12d%-12d%-12f%-12d\n", sco.elem[i].snum, sco.elem[i].cnum
		, sco.elem[i].score, sco.elem[i].trem );
	}
	fclose(fp);
	return OK;
}

Status SaveMenu( Std &stu, Class &cls, Score &sco )
{
	int i;
	char choice;
	cout<<endl;
	cout<<"1.保存学生信息     || 2.保存课程信息    "<<endl;
	cout<<"3.保存成绩信息     || 4.保存全部信息    "<<endl;
	cout<<"5.取消保存         ||                   "<<endl; 
	cout<<"请输入你的选择："<<endl;
	cin>>i;
	switch( i )
	{
		case 1:
			cout<<"你所要保存的学生信息为："<<endl;
			OutputStd( stu );
			cout<<"你确定要保存学生信息吗？（y/n)"<<endl;
			cin>>choice;
			if( choice == 'y' )
			{
				SaveStd( stu );
				cout<<"保存成功！"<<endl;
				return OK;
			}
			else if( choice =='n' )
			{
				cout<<"取消成功！"<<endl;
				return OK;
			}
			else
			{
				cout<<"请输入正确的选项！"<<endl;
				return ERROR; 
			}
			break;
		case 2:
			cout<<"你所要保存的课程信息为："<<endl;
			OutputCls( cls );
			cout<<"你确定要保存课程信息吗？（y/n)"<<endl;
			cin>>choice;
			if( choice == 'y' )
			{
				SaveCls( cls );
				cout<<"保存成功！"<<endl;
				return OK;
			}
			else if( choice =='n' )
			{
				cout<<"取消成功！"<<endl;
				return OK;
			}
			else
			{
				cout<<"请输入正确的选项！"<<endl;
				return ERROR; 
			}
			break;
		case 3:
			cout<<"你所要保存的成绩信息为："<<endl;
			OutputSco( sco );
			cout<<"你确定要保存成绩信息吗？（y/n)"<<endl;
			cin>>choice;
			if( choice == 'y' )
			{
				SaveSco( sco );
				cout<<"保存成功！"<<endl;
				return OK;
			}
			else if( choice =='n' )
			{
				cout<<"取消成功！"<<endl;
				return OK;
			}
			else
			{
				cout<<"请输入正确的选项！"<<endl;
				return ERROR; 
			}
			break;
		case 4:
			cout<<"你所要保存的学生信息，课程信息，成绩信息分别为："<<endl;
			OutputStd( stu );
			cout<<endl;
			OutputCls( cls );
			cout<<endl;
			OutputSco( sco );
			cout<<"你确定要所有信息吗？（y/n)"<<endl;
			cin>>choice;
			if( choice == 'y' )
			{
				SaveStd( stu );
				SaveCls( cls );
				SaveSco( sco );
				cout<<"保存成功！"<<endl;
				return OK;
			}
			else if( choice =='n' )
			{
				cout<<"取消成功！"<<endl;
				return OK;
			}
			else
			{
				cout<<"请输入正确的选项！"<<endl;
				return ERROR; 
			}
			break;
		case 5:
			cout<<"取消成功！"<<endl;
			break;
		default :
			cout<<"输入有误"<<endl;
			break; 
	}	
	return OK;
}

Status SearchOsco( Score &sco , Class &cls , Std &stu )
{
	int i, n, m, a, b;
	cout<<"请输入学生的学号："<<endl;
	cin>>n;
	for( i = 0; i < sco.length; i++ )
	{
		if( sco.elem[i].snum == n )
		{
			for( m = 0; m < stu.length; m++ )
			{
				if( stu.elem[m].num = n )
				{
					b = m;
					break;
				}
			}
			for( a = 0; a < cls.length; a++ )
			{
				if( sco.elem[i].cnum == cls.elem[a].num )
				{
					cout<<std::left<<setw(12)<<stu.elem[b].name<<std::left<<setw(12)
					<<cls.elem[a].name<<std::left<<setw(12)<<sco.elem[i].score<<endl;
				}
			}
		}
	}
}

Status SearchCSco( Std &stu, Class &cls, Score &sco )
{
	int i, n, m, a, b;
	cout<<"请输入课程号"<<endl;
	cin>>n;
	for( m = 0; m < sco.length; m++ )
	{
		for( i = 0; i < cls.length; i++ )
		{
			if( cls.elem[i].num == n )
				a = i;
		}
		if( sco.elem[m].cnum == n )
		{
			for( b = 0; b < stu.length; b++ )
			{
				if( stu.elem[b].num == sco.elem[m].snum )
				cout<<std::left<<setw(12)<<cls.elem[a].name<<std::left<<setw(12)
				<<stu.elem[b].name<<std::left<<setw(12)<<sco.elem[m].score<<endl;
			}
		}
	}
	return OK;
}

Status Searchlsco( Std &stu, Class &cls, Score &sco , char *clas )
{
	int i, n, a, b, m, x;
	cout<<"请输入班级名和课程号"<<endl;
	cin>>clas>>m;
	for( i = 0; i < sco.length; i++ )
	{
		for( n = 0; n < stu.length; n++ )
		{
			if( strcmp( stu.elem[n].clas, clas ) == 0 )
			{
				for( b = 0; b < sco.length; b++ )
				{
					if( sco.elem[b].snum == stu.elem[n].num && sco.elem[b].cnum == m )
					{
						for( x = 0; x < cls.length; x++ )
						{
							if( cls.elem[x].num == m )
							{
								cout<<std::left<<setw(12)<<clas<<std::left<<setw(12)
								<<cls.elem[x].name<<std::left<<setw(12)<<stu.elem[n].name
								<<std::left<<setw(12)<<sco.elem[b].score<<endl;
							}
						}
					}
				}
			}
		}
		break;
	}
	return OK;
}

 可供初学者学习，做得不好的地方望指正。