博客

（一）

新生基本信息统计软件


逐个录入学生信息，如：

学生姓名，性别，专业，出生日期，家庭地址，英语入学成绩。要求设计链表类来实现，并统计学生人数。

文本界面为：

1. 新增学生信息
2. 删除学生信息
3. 导入学生信息（已经保存于的文件信息）
4. 学生信息搜索（按姓名）
5. 学生信息统计（按专业或性别或年龄—年龄要自动计算）
6. 按英语成绩排序
7. 学生信息保存 ( 文件 )
8. 退出
   
   ******请选择：1

1) 案例一

#include<iostream>
#include<fstream>
#include<string.h>
using namespace std;
class Student
{   
    public:
	int num;
	char name[20];
	char sex;
	char address[100];
	int english;
	int born;
	char major [20];
    struct Student *next;	
};


//创建头结点 
/*S *head()
{
 S *head=new S;
 head->next=NULL;
 return head;
}*/


//定义学生类 
class Students
{
  	public:
  		Students()
  		{
  			head=new Student;
  			head->next=NULL;
		  }
void create();//创建链表
void edit(); //编辑函数 
void search();//显示函数
void add(); //添加函数
void delet(); //删除函数
void sort();//排序函数 
void show(); //查询函数
void sum(); //统计函数
void score();//成绩函数 
void read(); //读取函数
void write(); //存储函数
private:
	Student *head;
};


//创建函数的定义 
void Students::create()
{   	
	Student *p=head; 
     Student *q;
	q=new Student;
	cout<<"请输入学号:";
	cin>>q->num;
	cout<<"请输入姓名"<<endl;
	cin>>q->name;
	cout<<"请输入性别"<<endl;
	cin>>q->sex;
	cout<<"请输入专业";
	cin>>q->major;
	cout<<"请输入出生年份";
	cin>>q->born;
	cout<<"请输入家庭地址";
	cin>>q->address;
	cout<<"请输入英语成绩";
	cin>>q->english;
	q->next=NULL;
	p->next=q;
	p=q;	
}


//排序函数的定义 
void Students::sort()
{   int b=1;
    if(head->next==NULL)
    {
    	b=0;
	}
	if(b==0)
	{
		 cout<<"当前无数据"<<endl;
	}
	if(b==1)
	{
	Student *p,*q;
	int num1;
	char name1[20];
	char sex1;
	char address1[20];
	int english1;
	int born1;
	char major1[20];
	int num2;
	char name2[20];
	char sex2;
	char address2[20];
	int english2;
	int born2;
	char major2[20];
	for(p=head->next; NULL != p; p=p->next)
	{
		for(q=p->next; NULL !=q; q=q->next)
		{
			if(p->english < q->english)//当前一个学生的总分小于后一个学生的总分时，交换单链表的数据 
			{
				num1=p->num;
			strcpy(name1,p->name);
				sex1=p->sex;
			strcpy(address1,p->address);
				english1=p->english;
				born1=p->born;
			strcpy(major1,p->major);
				
				num2=q->num;
			strcpy(name2,q->name);
				sex2=q->sex;
			strcpy(address2,q->address);
				english2=q->english;
				born2=q->born;
			strcpy(major2,q->major);
				
				p->num=num2;
			strcpy(p->name,name2);
				p->sex=sex2;
			strcpy(p->address,address2);
				p->english=english2;
				p->born=born2;
			strcpy(p->major,major2);
				
				q->num=num1;
			strcpy(	q->name,name1);
				q->sex=sex1;
			strcpy(q->address,address1);
				q->english=english1;
				q->born=born1;
			strcpy(q->major,major1);
			}
		}
	}
	cout<<"排序完成"<<endl; 
   }
}


//显示函数 
void Students::search()
{ 
	Student *p=head->next;
	int b=1;
	if(p==NULL)
	{
		b=0;
	}
	if(b==0)
	{
	  cout<<"当前无数据"<<endl;
	}
	if(b==1)
	{
	 while(p)
	{   cout<<"学生学号";
	    cout<<p->num<<endl; 
	    cout<<"学生姓名";
		cout<<p->name<<endl;
		cout<<"学生性别";
		cout<<p->sex<<endl;
		cout<<"学生专业";
		cout<<p->major<<endl;
		cout<<"出生年份";
		cout<<p->born<<endl;
		cout<<"家庭地址";
		cout<<p->address<<endl;
		cout<<"英语成绩";
		cout<<p->english<<endl;
		p=p->next;
	 } 
    }
} 


//增加函数的定义 
void Students::add()
{
	Student *p=head->next;
	Student *q;
	int m=1;
	int n,b=1;
	//统计学生数 
    while(p->next!=NULL)
	 {	p=p->next;
		m++;
	 } 
	//cout<<"M="<<m;
    cout<<"请输入学号：";
    cin>>n;
	p=head->next;
	//判断学号是否重复 
	for(int i=1;i<=m;i++)
	{
	   if(p->num==n) 
	{
	   cout<<"编号重复"<<endl;
	   b=0;
	   break;
	   
	}
		p=p->next;
	}
	//cout<<b; 
	if(b!=0)
	{
		p=head;
	   	while(p->next!=NULL)
	   	p=p->next;
	   	q=new Student;
	   	q->num=n;
	cout<<"请输入姓名"<<endl;
	cin>>q->name;
	cout<<"请输入性别"<<endl;
	cin>>q->sex;
	cout<<"请输入专业";
	cin>>q->major;
	cout<<"请输入出生年份";
	cin>>q->born;
	cout<<"请输入家庭地址";
	cin>>q->address;
	cout<<"请输入英语成绩";
	cin>>q->english;
	q->next=NULL;
	p->next=q;
	p=q;
	}
}


//查询函数的定义 
void Students::show()
{   int b=0;
	Student *p=head->next;
	int a;
    cout<<"*****************************"<<endl;
    cout<<"****** 1 输入学生学号查询：**"<<endl;
    cout<<"****** 2 输入学生姓名查询：**"<<endl; 
    cout<<"*****************************"<<endl; 
	cin>>a;
	switch(a)
	{
		case 1:
			int i;
			cout<<"请输入学生学号";
			cin>>i;
			while(p!=NULL)
			{
				if(p->num==i)
				{
					cout<<"学生姓名";
		            cout<<p->name<<endl;
		            cout<<"学生性别";
		            cout<<p->sex<<endl;
	                cout<<"学生专业";
	              	cout<<p->major<<endl;
	            	cout<<"出生年份";
	            	cout<<p->born<<endl;
		            cout<<"家庭地址";
		            cout<<p->address<<endl;
		            cout<<"英语成绩";
		            cout<<p->english<<endl;
		         b++;
		        }
		        p=p->next;
			}	if(b==0)
				cout<<"该编号不存在";
			break;
		 case 2:
		 	char make[20];
		 	cout<<"请输入学生姓名";
		 	cin>>make;
		 	while(p!=NULL)
		 	{
		 		if(strcmp(p->name,make)==0)
		 			{
						cout<<"学生姓名";
		cout<<p->name<<endl;
		cout<<"学生性别";
		cout<<p->sex<<endl;
		cout<<"学生专业";
		cout<<p->major<<endl;
		cout<<"出生年份";
		cout<<p->born<<endl;
		cout<<"家庭地址";
		cout<<p->address<<endl;
		cout<<"英语成绩";
		cout<<p->english<<endl;
		b++;
			 }
			 p=p->next;	
			 }
			 if(b==0)
				cout<<"该学生不存在"; 
			break;
	            default:
		          cout<<" 请重新输入";
          
}
}


//统计函数的定义 
void Students::sum()
{   int a;
	Student *p=head;
	if(p->next==NULL) 
	{
	 cout<<"当前无数据"<<endl;
	 a=0;
	}
	if(a!=0)
	{
	p=head->next;	
	int i=0;
	int j=0;
	int n,s=0,d=0,m;
	int w=0,x=0;
	cout<<"**********************"<<endl;
	cout<<"*****1统计性别********"<<endl; 
	cout<<"*****2统计年龄********"<<endl;
	cout<<"*****3统计专业********"<<endl;
	cout<<"**********************"<<endl; 
	int a;
	cin>>a;
	switch(a)
	{
		case 1:
	          
            	while(p)
	       {
		      if(p->sex=='m')
		         i++;
	 	          else
		         j++;
		         p=p->next; 
             	}
	cout<<"男生："<<i<<endl;
	cout<<"女生："<<j<<endl;
	break;
	case 2:
		
		while(p)
		{
			n=p->born;
			m=2017-n; 
			if(m==18)
			s++;
			else
			d++;
			p=p->next; 
		}
		cout<<"18岁："<<s<<endl;
		cout<<"19岁："<<d<<endl;
		break; 
	case 3:
		
		while(p)
		{   m=strcmp(p->major,"software"); 
			if(m==0)
			w++;
			else
			x++;
			p=p->next; 
		}
		cout<<"软件专业："<<w<<endl;
		cout<<"化学专业:"<<x<<endl;
		break; 
		  default:
		 cout<<" 请重新输入";
	}
}
}


//删除函数的定义 
void Students::delet()
{
Student *p=head;
	Student *q;
	int a;
	if(p->next==NULL)
	{
	cout<<"当前无数据"<<endl;
	a=0;
	}
	//cout<<a;
	if(a!=0)
	{
	cout<<"请输入删除学生学号";
	int i;
	cin>>i;
	while(p->next != NULL)
     {
         if(p->next->num==i)
         {
            q = p->next;
            p->next = q->next;
            delete q;
            return;
         }
         p = p->next;
     }
	cout<<"学生不存在"<<endl;
   }
   
} 


//修改函数的定义 
void Students::edit()
{
	Student *p=head->next;
	Student *q=head->next; 
	cout<<"输入需要修改学生的学号"; 
	int n;
	int b=0;
	int j=1;
	cin>>n;
	while(p)
	{
		if(p->num==n)
		{
			b=1;
		}
	p=p->next;
	}
	if(b==0)
	cout<<"没有该学生"<<endl; 
	if(b==1)
	{
	p=head->next;
	while(p)
	{
		if(p->num==n)
		{   cout<<"************************"<<endl;
		    cout<<"*****1修改学生学号******"<<endl;
			cout<<"*****2修改学生姓名******"<<endl;
			cout<<"*****3修改学生性别******"<<endl; 
			cout<<"*****4修改学生专业******"<<endl; 
			cout<<"*****5修改出生年份******"<<endl; 
			cout<<"*****6修改家庭地址******"<<endl; 
			cout<<"*****7修改英语成绩******"<<endl;  
			cout<<"************************"<<endl;
			int m;
			cin>>m;
			switch(m)
			{
				case 1:
						cout<<"请输入学号:";
						int i;
						cin>>i;
		                while(q)
		                {   
		                	if(q->num==i)
		                	{
		                		cout<<"编号重复";
		                		break;
		                		j=0;
							}
							q=q->next; 
						}
					//	cout<<j<<endl;
						if(j!=0)
	                    p->num=i;
	                    break;
	            case 2:
					cout<<"请输入姓名"<<endl;
	                cin>>p->name;     
					break;
				case 3:
				 cout<<"请输入性别"<<endl;
	             cin>>p->sex;   
	             break;
	            case 4:
				cout<<"请输入专业";
	            cin>>p->major; 
	            break;
	            case 5:
	            	cout<<"请输入出生年份";
	                cin>>p->born;
	            break;
	            case 6:
	            	cout<<"请输入家庭地址";
	                cin>>p->address;
	            break;
	            case 7:
	            	cout<<"请输入英语成绩";
	                cin>>p->english;
	            break;
	             default:
		     cout<<" 请重新输入"<<endl;
			}
			break;
		}
	}
}
}


//成绩处理函数的定义 
void Students::score()
{    
	Student *p=head->next;
	int b=1;
	if(p==NULL)
	{
		b=0;
	}
	if(b==0)
	{
	cout<<"当前无数据"<<endl;
	}
	if(b==1)
	{
    int m=1;
	while(p->next!=NULL)
	{
		p=p->next;
		m++;
	}
	//cout<<"M="<<m<<endl;
	int sum=0;
	p=head->next;
	while(p)
	{
		sum=sum+p->english;
		p=p->next;
	}
    float ave;
	ave=sum/m;
	cout<<"英语平均分为"; 
	cout<<ave<<endl;
	p=head->next;
	cout<<"不及格学生:"<<endl;
	int n=0;
	while(p)
	{
		if(p->english<60)
		{
		cout<<"学生学号:"<<p->num<<" "<<"学生姓名"<<p->name<<" "<<"学生成绩"<<p->english<<endl;
		n++;
		}
		p=p->next;
	}
	cout<<"不及格人数"; 
	 cout<<n;
}
}


//文件写入函数的定义 
void Students::write()
{
	ofstream outfile("d:\\file.txt");
	if(!outfile)
	{
		cerr<<"open error!"<<endl;
		exit(1);
	}
	Student *p=head->next;
	while(p)
	{
		outfile<<p->num<<" ";
		outfile<<p->name<<" ";
		outfile<<p->sex<<" ";
		outfile<<p->major<<" ";
		outfile<<p->born<<" ";
		outfile<<p->address<<" ";
		outfile<<p->english	<<" ";		
		p=p->next;
	}
	outfile.close();
	cout<<"保存完成"<<endl; 
}


//文件读取 
void Students::read()
{
	ifstream infile("d:\\file.txt");
	if(!infile)
	{
		cerr<<"open error!"<<endl;
		exit(1);
	}
	Student *p=head,*q;
	//将文件的数据输入到链表中 
	while(!infile.eof())
	{  
	  	q=new Student;
	  	if(infile>>q->num)
		  {
		infile>>q->name;
	  	infile>>q->sex;
	  	infile>>q->major;
	  	infile>>q->born;
	  	infile>>q->address;
	  	infile>>q->english;
		q->next=NULL;
		p->next=q;
		p=q;
		  }
	  	else
	  	break;
		
		
	}
	cout<<"读取成功"<<endl; 
    infile.close();
} 


void f()
{
cout<<"************************************"<<endl;
cout<<"************************************"<<endl;
cout<<"*******欢迎使用新生报到系统*********"<<endl;
cout<<"************************************"<<endl;
cout<<"************************************"<<endl;
cout<<"点击Enter键进行下一步";
getchar();
system("cls");
} 


void g()
{   
	cout<<"**************************************"<<endl;
	cout<<"********** 1 输入学生信息 ************"<<endl;
	cout<<"********** 2 增加学生信息 ************"<<endl;
	cout<<"********** 3 删除学生信息 ************"<<endl;
	cout<<"********** 4 查询学生信息 ************"<<endl;
	cout<<"********** 5 修改学生信息 ************"<<endl;
	cout<<"********** 6 统计学生信息 ************"<<endl;
	cout<<"********** 7 显示学生信息 ************"<<endl;
    cout<<"********** 8 保存学生信息 ************"<<endl;
	cout<<"********** 9 读取学生信息 ************"<<endl;
	cout<<"********** 10排序学生信息 ************"<<endl;
	cout<<"********** 11处理成绩信息 ************"<<endl;
	cout<<"********** 12退出    系统 ************"<<endl;
	cout<<"**************************************"<<endl;
}


int main()
{  f(); 
    Students stu;
	//St *h=head();
    while(1)
	{
	int i;
	g();
	int n;
	cin>>n;
	switch(n)
	{
		case 1: stu.create();
		break;
		case 2: stu.add();
		break;
		case 3: stu.delet();
		break;
		case 4:stu.show();
		break;
		case 5: stu.edit();
		break;
		case 6:stu.sum();
		break;
		case 7:	stu.search(); 
		break;
	    case 8:stu.write();
		break;
	    case 9:stu.read();
		break;
		case 10:stu.sort();
			break;
		case 11:stu.score();
		    break; 
		case 12:
			exit(0);
			break;
		default:
		cout<<"请重新输入";
	}
	if(i==-1)
	break;
	cout<<"点击Enter键进行下一步";
	getchar();
	getchar();
	system("cls");
	}
	return 0;
}

2) 案例二

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#define LEN sizeof(struct student)
#include<windows.h>
typedef struct student{
	int id;
	int num;
	char name[20];
	int score;
	struct student *next;//指针域(指向节点的指针）
}stu; 
struct student *creat() //创建头节点 
{
	stu *head;
	head=(stu*)malloc(LEN);
	if(head==NULL)
		printf("申请失败");
	else
	{
		head->next ==NULL;
	}
	return head;
}

void init_data(stu *p)  //初始化数据 
{
	int n,i;
	stu *q=NULL;
	printf("请输入要添加的学生个数：");
	scanf("%d",&n);
	getchar(); 
	for(i=0;i<n;i++)
	{
		q=(struct student*)malloc(LEN);
		printf("请输入第%d个学生的学生序号：",i+1);
		scanf("%d",&q->id);
		printf("请输入第%d个学生的学生号：",i+1);
		scanf("%d",&q->num );
		printf("请输入第%d个学生的姓名：",i+1);
		scanf("%s",q->name );
		printf("请输入第%d个学生的分数：",i+1);
		scanf("%d",&q->score ); 
		p->next =q;
		p=p->next ;
	}
	q->next =NULL; 
	printf("初始化信息成功\n");
}

void insert_data(stu *p) //插入学生信息
{
	stu *Q=NULL;
	stu *q=p->next ;
	int n;
	printf("你要插入的个体数：");
	scanf("%d",&n);
	int i;
	for(i=1;i<=n;i++)
	{
		Q=(struct student*)malloc (LEN); 
		printf("请输入你要加入的学生序号：");
		scanf("%d",&Q->id );
		printf("请输入你要加入的学生号：");			
		scanf("%d",&Q->num );
		printf("请输入你要加入的学生名字：");
		scanf("%s",Q->name );
		printf("请输入你要加入的学生分数：");
		scanf("%d",&Q->score );
		Q->next =q->next ;
		q->next =Q;	
	}
		q=q->next ;//指针后移 
		printf("添加成功\n");
}  

void del_data(stu *p)  //删除学生信息 
{
	stu *q=p->next ;
	stu *l=p;
	bool flag=false;
	int i;
	printf("请输入要删除的学生的编号：");
	scanf("%d",&i);
	while(p)
	{
		
		if(q->id ==i)
		{
			l->next =q->next ;
			free(q);
			flag=true;
			break;
		}
		q=q->next ;
		l=l->next ;
	}
	if(flag==false)
	{
	printf("无学生记录\n");
	}
	printf("删除成功\n");
} 

void find_data(stu *p) //查找学生信息 
{
	stu *q=p->next ;
	bool flag=false;
	int i;
	printf("请输入你要查找的学生号：");
	scanf("%d",&i);
	while(q)
	{

		if(i==q->id )
		{
			printf("学生序号：%d 学生学号：%d 学生姓名：%s 学生成绩：%d\n",q->id ,q->num ,q->name ,q->score );
			flag=true;	
		} 
		q=q->next ; 
	}
	if(flag==false)
	{
		printf("查找失败\n");
	}	
}

void change_data(stu *p) //修改学生信息
{
	stu *q=p->next ;
	bool flag=false;
	int i;
	printf("请输入需要修改的学生序号：");
	scanf("%d",&i);
	while(q)
	{
		if(q->id ==i)
		{
			printf("请输入修改后的编号：");
			scanf("%d",&q->id );
			printf("请输入修改后的学生号：");
			scanf("%d",&q->num );
			printf("请输入修改后的姓名：");
			scanf("%s",&q->name );
			printf("请输入修改后的分数：");
			scanf("%d",&q->score );
			flag=true;
		}
		q=q->next ;
	}
	if(flag==false)
	{
		printf("修改失败\n");
	}else{
		printf("修改成功\n");
	} 
} 
void traverse(stu *p) //遍历链表 
{
	stu *q=p->next ;
	while(q!=NULL)
	{
			printf("学生序号：%d 学生学号：%d 学生姓名：%s 学生成绩：%d\n",q->id ,q->num ,q->name ,q->score );
			q=q->next ;
	} 
} 

void choice()        //显示列表 
{
	
	stu *p;
	p=creat();
	printf("登录日期：\n"); 
	system("date/t");
	printf("登陆时间：\n"); 
	system("time/t");
	while(1)
	{
		
		printf("-----------欢迎来到学生管理系统----------\n") ;
		printf("\t1.****初始化学生信息****\n"); 
		printf("\t2.****插入学生信息****\n"); 
		printf("\t3.****删除学生信息****\n");
		printf("\t4.****查找学生信息****\n");
		printf("\t5.****修改学生信息****\n");
		printf("\t6.****浏览学生信息****\n");
		printf("\t0.****退出系统****\n");
		printf("-----------------------------------------\n") ;
		int choice;
		printf("请选择: ");
		scanf("%d",&choice);
		switch(choice)
		{
			case 1:
				printf("初始化信息：\n");
				init_data(p);
				break;
			case 2:
				system("CLS"); 
				printf("插入信息\n");
				insert_data(p);
				break;
			case 3:
				system("CLS"); 
				printf("删除信息\n");
				del_data(p);
				break;
			case 4:
				system("CLS"); 
				printf("查找信息\n");
				find_data(p);
				break;
			case 5:
				system("CLS"); 
				printf("修改信息\n");
				change_data(p);
				break;		
			case 6:
				system("CLS"); 
				printf("浏览信息\n"); 
				traverse(p);
				break;
			case 0:
				system("CLS"); 
				printf("谢谢使用,再见！！！\n");
				exit(0);
			default:
				system("CLS"); 
				printf("输入错误，请重新输入！！！\n"); 
				break;
		}
	}

}

void registerall(){
	
 	char a[20],b[20],c[20],d[20];
	while(1)
	{
		int n;
		printf("******** 1、注册 ********\n");
		printf("******** 2、登陆 ********\n");
		printf("******** 3、退出 ********\n");
        printf("请输入你的编号："); 
		if(scanf(" %d",&n) == 1 ){
				switch(n){
					case 1:{
					 while(1)
							{
							int m;
							printf("1 注册 2 退出\n");
			  if (scanf(" %d",&m) == 1 ){
						if( m == 2 ){
							  break;
							}
					    else if ( m == 1 ){
							printf("注册账户：");
							scanf(" %s",&a);
							printf("注册密码：");
							scanf(" %s",&b);
						} else{
						printf("输入错误\n");
						}
					}   else{
							printf("非法输入！\n");
							break;
						}
			}
					break;
						}
						
				    case 2:{
						while(1)
						{
							int n;
							printf("1 登陆 2 退出登陆\n");
							if ( scanf("%d",&n) == 1 ){
							   if( n == 2 ){
							    break;
						                }
							else if ( n == 1 ){
							printf("输入账户：");
							scanf(" %s",&c);
							printf("输入密码：");
							scanf(" %s",&d);
							if(strcmp(a,c)==0&&strcmp(b,d)==0){
									printf("登陆成功！\n");
									printf("内容正在加载中，请等待:\n");
								for(int j=0; j<8; j++){
										Sleep(500);
									printf(" . ");
								}
									   Sleep(2500);
									   system("CLS");
									   system ("color F");
									   choice(); 
						 }else{
					         printf("账户或密码错误!\n");
							  }
					     }else{
							printf("input error\n");
						}
				      	}else{
							printf("非法输入！重新运行!\n");
							break;
						}
			   }
							break;
		}
							
					case 3:{
							printf("退出成功！\n");
							exit(0);
						}
					default:
							printf("input error!\n");
						}
					}
		else{
			printf("非法输入！重新运行!\n");
			break;
					}
		}
}
int main()
{
	system("CLS"); 
	system ("color 5F");
	registerall(); 
	return 0;
}

3) 案例三

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
typedef struct student {
	int num;
	char name[20];
	char add[20];
	float achievement;
	struct student *next;
} happy,*point;



struct student* creatlist() {
	point head=(point)malloc(sizeof(happy));;
	point two=head;
	int i,n;
	int num;
	char name[20];
	char add[20];
	float achievement;
	printf("请输入学生个数：");
	scanf("%d",&n);
	for(i=0; i<n; i++) {
		point one=(point)malloc(sizeof(happy));
		printf("请输入第%d个同学的数据：",i+1);
		int num;
		char name[20];
		char add[20];
		float achievement;
		scanf("%d %s %s %f",&num,name,add,&achievement);
		one->num =num;
		strcpy(one->name ,name);
		strcpy(one->add,add);
		one->achievement =achievement;
		two->next =one;
		one->next=NULL;
		two=one;
	}
	return head;

}



void travellist(point head) {
	int i=0;
	point one=head->next ;
	while(one!=NULL) {
		i++;
		printf("第%d个学生的数据：\n",i);
		printf("%d ",one->num );
		printf("%s ",one->name);
		printf("%s ",one->add);
		printf("%f \n",one->achievement);
		one=one->next ;
	}
	printf("\n");
}



void insert(point head) {
	int num;
	printf("输入添加的学生位置(在它之后添加)");
	scanf("%d",&num);
	int num_;
	char name[20];
	char add[20];
	float achievement;
	scanf("%d %s %s %f",&num_,name,add,&achievement);
	point one=head;
	point three;
	int i=0;
	while(i<num) {
		one=one->next ;
		i++;
	}
	three=one->next ;
	point two=(point)malloc(sizeof(happy));
	two->num =num_;
	strcpy(two->name ,name);
	strcpy(two->add,add);
	two->achievement =achievement;
	one->next =two;
	two->next =three;
}



void delate(point head) {
	int i=0;
	int n;
	int num;
	point one=head;
	point two;
	printf("输入你要删除的学生位置:");
	scanf("%d",&num);
	while(i<num-1) {
		one=one->next ;
		i++;
	}
	two=one->next ;
	one->next =two->next ;
	free(two);
}



void search(point head) {
	point one=NULL;
	one=head->next ;
	int num;
	printf("你要查询的学号：") ;
	scanf("%d",&num);
	while(one!=NULL) {
		
		if(one->num ==num) {
			printf("查找成功\n");
			printf("学号：%d\n",one->num );
			printf("姓名：%s\n",one->name  );
			printf("地址：%s\n",one->add  );
			printf("成绩：%f\n",one->achievement  );
		    break; 
		} 
		one=one->next ;
	}

}



void revise(point head) {
	int num;
	int num_; 
	char name[20];
	char add[20];
	float achievement;
	int n=0;
	point one=head;
	printf("输入学生位置：");
	scanf("%d",&num);
	while(n<num) {
		one=one->next ;
		n++;
	}
	scanf("%d %s %s %f",&num_,name,add,&achievement);
	one->num =num_;
	strcpy(one->name ,name);
	strcpy(one->add,add);
	one->achievement =achievement;
}



void headline() {
	printf("1.输入学生数据\n");
	printf("2.添加学生数据\n");
	printf("3.删除学生数据\n");
	printf("4.查询学生数据\n");
	printf("5.修改学生数据\n");
	printf("6.退出系统\n");
}



int main() {
	int i;
	point head;
	do{
		printf("\n");
		headline();
		printf("\n\n");
		printf("请选择1——9：");
		scanf("%d",&i);
		switch(i)
		{
			case 1:head=creatlist();
			       travellist(head);     
			       break;
			case 2:insert(head);
			       travellist(head); 
				   break;       
            case 3:delate(head);
			       travellist(head);
				   break;
			case 4:search(head);
				   break;
			case 5:revise(head);
			       travellist(head);
				   break;
			case 6:break;
			default:printf("选择错误，请重新选择");  	     	 
		 } 
		 
	}while(i!=6);
	return 0; 
}

4) 案例四

#include <iostream>
using namespace std;
#include<stdio.h>
#include <string.h>
#include <stdlib.h>
#include <conio.h>
#define N 1000
 
typedef struct student
 
{
 
    int number;
    char name[20];
    int grade;
    int gaoshu;
    int yingyu;
    int jisuanji;
    int sum;
 
}STUDENT;
 
STUDENT student[N];
 
int shuliang=0;       //用于记录有多少学生
class Student
{
    public:
    void fhzjm();
    void DengJi();
    void ShanChu();
    void LiuLan();
    void ChaZhao();
    void PaiXu();
    void Save();
    void menu();
    void DaoRu();
};
 
void Student::fhzjm()        //每次操作结束  来提醒是否继续进行操作
{
    char biaozhi[20];
    cout<<endl;
   cout<<"还需要操作么？如果需要操作请输入：yes，否则请输入：no"<<endl;
   cin>>biaozhi;
    if(strcmp(biaozhi,"yes")==0)
    {
        menu();
    }
    else if(strcmp(biaozhi,"no")==0)
    exit(0);               //退出系统    这是一个库函数   用于结束程序
 
    else
        {
            cout<<"请输入正确的字符，谢谢！"<<endl;
            fhzjm();
        }
}
 
void Student::DengJi()                       //登记学生信息函数
 
{
 
    int rs;      //用于记录要输入多少条学生信息
    int i,k=1;
    system("CLS");
    cout<<"请输入需要输入几个学生信息："<<endl;
    cin>>rs;
    for(i=shuliang;i<shuliang+rs;i++,k++)
    {
        cout<<"请输入第"<<k<<"个学生的学号：";
       cin>>student[i].number;
        cout<<"请输入学生的姓名：";
       cin>>student[i].name;
        //cout<<"请输入学生3门课的成绩：";
        cout<<"请输入第高数课的成绩：";
        cin>>student[i].gaoshu;
        cout<<"请输入英语课的成绩：";
       cin>>student[i].yingyu;
      cout<<"请输入第计算机课的成绩：";
       cin>>student[i].jisuanji;
    }
    shuliang=shuliang+rs;
    fhzjm();
}
 
void Student::ShanChu()     //删除学生信息
{
    char shanchuinfo[10];
    system("CLS");       //清屏函数   这是一个库函数    用于清除控制台中的所有信息
  cout<<"删除全部学生信息请输入\"all\"，删除指定学号的学生信息请输入\"one\"\n";
  cin>>shanchuinfo;
    if(strcmp(shanchuinfo,"all")==0)
    {
        int j;
     cout<<"你删除的学生信息如下："<<endl;
      cout<<"-----------学号-------------姓名-------------高数--------------英语--------------计算机\t"<<endl;
        for(j=0;j<shuliang;j++)
       cout<<"----%d-------%s-------%d-------%d-------%d\t\n",student[j].number,student[j].name,student[j].gaoshu,student[j].jisuanji;
        shuliang=0;
       cout<<"删除成功"<<endl;
    }
 
    else if(strcmp(shanchuinfo,"one")==0)
    {
        struct student *p=NULL;
        int choice;
        int i,j,k=0;
      cout<<"请输入你要删除的人的学号:";
       cin>>choice;
        for(i=0;i<shuliang;i++)
        {
            if(choice==student[i].number)
            {
                k=1;j=i;break;
            }
        }
    if(k)
    {
        if(shuliang==1)
        {
            p=&student[0];
            free(p);
            shuliang=0;
        }
 
        else
        {
            for(i=j;i<shuliang;i++)
            {
                student[i]=student[i+1];
            }
            shuliang=shuliang-1;
        }
 
      cout<<"删除成功"<<endl;
    }
 
    else
    {
       cout<<"输入数据错误！"<<endl;
    }
 
    }
    fhzjm();
}
 
void Student::LiuLan()    //浏览操作函数
{
    int i;
    system("CLS");
    if(shuliang==0)
    {
       cout<<"系统里面没有任何学生的信息！"<<endl;
    }
 
    else
    {
        for(i=0;i<shuliang;i++)
        {
 
            cout<<"第"<<i+1<<"个学生的学号为："<<student[i].number<<endl;
         cout<<"第"<<i+1<<"个学生的姓名为："<<student[i].name<<endl;
           cout<<"第"<<i+1<<"个学生的高数课的成绩为："<<student[i].gaoshu<<endl;
          cout<<"第"<<i+1<<"个学生的英语课的成绩为："<<student[i].yingyu<<endl;
           cout<<"第"<<i+1<<"个学生的计算机课的成绩为："<<student[i].jisuanji<<endl;
            student[i].sum=student[i].gaoshu+student[i].yingyu+student[i].jisuanji;
           cout<<"第"<<i+1<<"个学生的总成绩为："<<student[i].sum<<endl;
        }
 
    }
    fhzjm();
}
 
void Student::ChaZhao()     //查找函数  实现查找功能   分为三种查询 按学号查询   按姓名  按成绩
{
    int xx;
    char choice,yy[20];
    int i,j,k=0;
    system("CLS");
    if(shuliang==0)
    {
        cout<<"系统里面没有任何学生的信息！"<<endl;
        fhzjm();
    }
 
     cout<<"三种查找方式：学号，姓名，成绩"<<endl;
     cout<<"如果按学号查找请输1，如果按姓名查找请输2，如果按成绩查找请输3"<<endl;
     cout<<"请输入您查找的方式：";
  cin>>choice;
    if(choice=='1')
    {
          cout<<"请输入需要查找学生的学号：";
       cin>>xx;
         cout<<"您所查找的学生的信息为："<<endl;
        cout<<"----学号----姓名----高数成绩----英语成绩----计算机成绩----\t"<<endl;
        for(i=0;i<shuliang;i++)
        {
            if(xx==student[i].number)
            {
                j=i;k=1;
               cout<<"----%d-------%s-------%d-------%d-------%d----\t\n",student[j].number,student[j].name,student[j].gaoshu,student[j].yingyu,student[i].jisuanji;
            }
        }
 
        if(k==0)
         cout<<"输入信息有误："<<endl;
    }
 
    else if(choice=='2')
    {
         cout<<"请输入需要查找学生的姓名:";
        cin>>yy;
         cout<<"您所查找的学生的信息为："<<endl;
          cout<<"----学号----姓名----高数成绩----英语成绩----计算机成绩----\t"<<endl;
        for(i=0;i<shuliang;i++)
        {
            if(strcmp(yy,student[i].name)==0)
            {
                j=i;k=1;
                 cout<<"----%d-------%s-------%d-------%d-------%d----\t\n",student[j].number,student[j].name,student[j].gaoshu,student[j].yingyu,student[j].jisuanji;
            }
 
        }
        if(k==0)
         cout<<"输入信息有误："<<endl;
    }
 
    else if(choice=='3')
    {
         cout<<"请输入需要查找学生的成绩："<<endl;
        cin>>xx;
      cout<<"您所查找的学生的信息为："<<endl;
          cout<<"----学号----姓名----高数----英语----计算机----\t"<<endl;
        for(i=0;i<shuliang;i++)
        {
            if(xx==student[i].grade)
            {
                j=i;k=1;
                cout<<"----%d-------%s-------%d-------%d-------%d----\t\n",student[j].number,student[j].name,student[j].gaoshu,student[j].yingyu,student[i].jisuanji;
            }
        }
        if(k==0)
         cout<<"输入信息有误："<<endl;
    }
    fhzjm();
}
 
void Student::PaiXu()     //排序函数   执行排序操作
{
    struct student *p1[N],**p2,*temp;
    int i,j;
    system("CLS");
    p2=p1;
    for( i=0;i<shuliang;i++)
    {
        p1[i]=student+i;
    }
 
    for( i=0;i<shuliang;i++)
    {
        for( j=i+1;j<shuliang;j++)
        {
            if((*(p2+i))->sum<(*(p2+j))->sum)
            {
                temp=*(p2+i);*(p2+i)=*(p2+j);*(p2+j)=temp;
            }
        }
    }
 
    cout<<"按照总成绩排序之后的信息为："<<endl;
 
     cout<<"----学号----姓名----总成绩----\t"<<endl;
 
    for( i=0;i<shuliang;i++)
    {
        student[i].sum=student[i].gaoshu+student[i].yingyu+student[i].jisuanji;
         cout<<"----%d-----%s----%d-----\n",(*(p2+i))->number,(*(p2+i))->name,(*(p2+i))->sum;
    }
    fhzjm();
}
 
void Student::Save()     //保存数据    把数据写到文件操作
{
    int i;
    FILE *rs;
    if((rs=fopen("student.txt","w"))==NULL)
    {
         cout<<"not open";
        exit(0);
    }
 
    for(i=0;i<shuliang;i++)
    {
        fwrite(&student[i], sizeof(student[i]), 1, rs);
    }
 
    if(ferror(rs))
    {
        fclose(rs);
        perror("写文件失败！\n");
        return;
    }
 
     cout<<"存储文件成功！"<<endl;
    fclose(rs);
    fhzjm();
}
 
void Student::DaoRu()
{
    struct student t;
    int i=0;
    FILE* fp = fopen("student.txt", "r");
    shuliang=0;
    if(NULL==fp)
    {
        perror("读取文件打开失败！\n");
        return;
    }
    memset(student,0x0,sizeof(student));
    while(1)
    {
        fread(&t,sizeof(t),1,fp);
        if(ferror(fp))
        {
            fclose(fp);
            perror("读文件过程失败！\n");
            return;
        }
 
        if(feof(fp))
        {
            break;
        }
        student[i]=t;
        i++;
    }
    fclose(fp);
    shuliang=i;
     cout<<"导入文件成功！"<<endl;
    fhzjm();
}
void Student::menu()
{
    int n=0;
    system("CLS");
   cout<<" ==================学生信息管理系统==============="<<endl;
  cout<<" =                1.登记学生信息                 ="<<endl;
  cout<<" =                2.删除学生信息                 ="<<endl;
   cout<<" =                3.浏览学生信息                 ="<<endl;
  cout<<" =                4.查找学生信息                 ="<<endl;
   cout<<" =                5.根据总成绩排序               ="<<endl;
    cout<<" =                6.存储到文件                   ="<<endl;
   cout<<" =                7.从文件导入                   ="<<endl;
  cout<<" =                8.退出系统                     ="<<endl;
  cout<<" ================================================="<<endl;
  cout<<" 请选择：";
  cin>>n;
    switch (n)
    {
        case 1:
            DengJi();break;    //等记信息
        case 2:
            ShanChu();break;   //删除信息
        case 3:
            LiuLan();break;     //浏览信息
        case 4:
            ChaZhao();break;     //查找信息
       case 5:
            PaiXu();break;     //对成绩记性排序
        case 6:
            Save();break;       //保存数据到文件中
        case 7:
            DaoRu();break;       //把文件中的数据导入到程序中
        case 8:
        exit(0);break;      //退出系统
    }
}
 
int main()
{
    Student student;
    student.menu();
    return 0;
} 

5) 案例五

#include<iostream>
#include<cstdlib>
#include<cstring>
#include<fstream>
#include<windows.h>
using namespace std;
class student {
	public:
		int num;           //学号
		char s[20];
		char name[20];       //姓名
		double 	score[6];   //成绩
		double total;            //总分
		student *next;
		void input();
		void  readfile(ifstream&in);  // 读出数据
};
void student::input() {   //输入信息   调用它
	cout<<"请输入学号：";
	cin>>num;
	cout<<"请输入姓名：";
	cin>>name;
	int a,b,c,d;
	cout<<"请输入语文：";
	cin>>a;
	while(a>150||a<0) {
		cout<<"输入成绩有错误，请从新输入：";
		cin>>a;
	}
	cout<<"请输入高数：";
	cin>>b;
	while(b>150||b<0) {
		cout<<"输入成绩有错误，请从新输入：";
		cin>>b;
	}
	cout<<"请输入英语：";
	cin>>c;
	while(c>150||c<0) {
		cout<<"输入成绩有错误，请从新输入：";
		cin>>c;
	}
	cout<<"请输入专业课：";
	cin>>d;
	while(d>150||d<0) {
		cout<<"输入成绩有错误，请从新输入：";
		cin>>d;
	}

	score[1]=a;
	score[2]=b;
	score[3]=c;
	score[4]=d;
	total=a+b+c+d;
	next=NULL;

}
void student::readfile(ifstream&in) {   //文件的调用  直接调用  不能其他的  得一一的调用
	in>>num>>name>>score[1]>>score[2]>>score[3]>>score[4]>>total;

}
class  studentmessage {
	public:
		studentmessage();
		void add();//添加
		void display();
		void maxmin();//输出最大最小的姓名
		void save();//保存文件
		void rank();//排序
		void swap(student*p,student*q);
		void menu();//菜单
		void xiugai();//修改
		void tianjia();
		void shanchu();
		void chazhao();
		void average();
		void youxiu();
		void bukao();
		void duqu();
	protected:
		student   *head;
		student    *tail;
		ofstream   out;
		ifstream   in;

};
studentmessage::studentmessage() {        //！！！   多看看
	head=new student;
	head->next=new student;
	tail=head->next;
	ifstream  in("file.text");//打开文件
	char  ch=in.get();  //    //读取一个文件的的字符    ！！so  保存时添加无关一个字符
	if(in.eof()) {
		cout<<"是一个新系统，无学生信息。请先输入"<<endl;
	}
	while(!in.eof()) {               //文件里有东西  读取  自动
		tail->readfile(in);
		if(tail->name[0]=='\0') {    //判断mane  又没空格
			break;
		}
		tail->next= new  student;     //  建立一个空间
		tail->next->next=NULL;       //不同
		tail=tail->next;
		tail->next=NULL;            //用tail NULL 来判断   // 尾插


	}

}

void studentmessage::add() {
	system("cls");
	int flag=1;
	while(flag) {
		tail->input();
		tail->next=new student;
		tail->next->next=NULL;
		tail=tail->next;

		cout<<"是否输入（Y/N)"<<endl;
		char  n;
		cin>>n;
		if(n=='N'|| n=='n') {
			flag=0;
		}
	}
	system("pause");
}
void studentmessage::display() {
	system("cls");
	student  *p=head->next;
	if(p==NULL) {
		cout<<"没有"<<endl;
	}

	for(p; p->next!=NULL; p=p->next) {   //???
		cout<<"-----------------------"<<endl;
		cout<<"学号："<<p->num<<endl;
		cout<<"姓名："<<p->name<<endl;
		cout<<"语文："<<p->score[1]<<endl;
		cout<<"高数："<<p->score[2]<<endl;
		cout<<"英语："<<p->score[3]<<endl;
		cout<<"专业课："<<p->score[4]<<endl;
		cout<<"总分："<<p->total<<endl;
		cout<<"------------------------"<<endl;
	}
	system("pause");
}
void studentmessage::swap(student *p,student *q) {
	student   *temp=new student;
	temp->num=p->num;
	strcpy(temp->name,p->name);
	temp->score[1]=p->score[1];
	temp->score[2]=p->score[2];
	temp->score[3]=p->score[3];
	temp->score[4]=p->score[4];
	temp->total=p->total;

	p->num=q->num;
	strcpy(p->name,q->name);
	p->score[1]=q->score[1];
	p->score[2]=q->score[2];
	p->score[3]=q->score[3];
	p->score[4]=q->score[4];
	p->total=q->total;

	q->num=temp->num;
	strcpy(q->name,temp->name);
	q->score[1]=temp->score[1];
	q->score[2]=temp->score[2];
	q->score[3]=temp->score[3];
	q->score[4]=temp->score[4];
	q->total=temp->total;
}
void studentmessage::rank() {
	system("cls");
	student  *p,*q;
	p=head->next;
	for(p; p->next!=NULL; p=p->next) {
		for(q=p->next; q->next!=NULL; q=q->next) {
			if(q->total>p->total)
				swap(q,p);
		}
	}
	cout<<"排序成功"<<endl;
	student *p1=head->next;
	for(p1; p1->next!=NULL; p1=p1->next) {
		cout<<"-----------------------"<<endl;
		cout<<"学号："<<p1->num<<endl;
		cout<<"姓名："<<p1->name<<endl;
		cout<<"语文："<<p1->score[1]<<endl;
		cout<<"高数："<<p1->score[2]<<endl;
		cout<<"英语："<<p1->score[3]<<endl;
		cout<<"专业课："<<p1->score[4]<<endl;
		cout<<"总分："<<p1->total<<endl;
		cout<<"------------------------"<<endl;
	}


	system("pause");
}
void studentmessage::menu() {
	system("cls");
	system("date/t");
	system("time/t");
	system("color 5F");
	cout<<"\t\t\t\t***************************************************"<<endl;
	cout<<"\t\t\t\t-------------------学生管理系统--------------------"<<endl;
	cout<<"\t\t\t\t                    1.录入信息                     "<<endl;
	cout<<"\t\t\t\t                    2.显示信息                     "<<endl;
	cout<<"\t\t\t\t                    3.修改信息                     "<<endl;
	cout<<"\t\t\t\t                    4.删除信息                     "<<endl;
	cout<<"\t\t\t\t                    5.添加信息                     "<<endl;
	cout<<"\t\t\t\t                    6.查找信息                     "<<endl;
	cout<<"\t\t\t\t                    7.保存信息                     "<<endl;
	cout<<"\t\t\t\t                    8.退出系统                     "<<endl;
	cout<<"\t\t\t\t***************************************************"<<endl;
	system("pause");
}
void studentmessage::xiugai() {
	system("cls");
	student *p=head->next;
	int flag=1;
	while(flag) {
		int n;
		cout<<"修改输入学号："<<endl;
		cin>>n;
		while(p->num!=n&&p->next!=NULL) {
			//	cout<<"asdasd";
			p=p->next;
		}
		p->input();
		cout<<"修改成功"<<endl;
		cout<<"选择是否接着修改(Y/N)"<<endl;
		char  k;
		cin>>k;
		if(k=='N'||k=='n') {
			flag=0;
		}
	}
	system("pause");
}
void studentmessage::tianjia() {
	system("cls");
	student *p=head;
	student *p1=head->next;
	student *p2=new student;
	char  k;
	while(k!='N') {
		int n;
		cout<<"输入你添加的位数"<<endl;
		cin>>n;
		int i=0;
		while(n!=i+1) {
			p=p->next;
			p1=p->next;
			i++;
		}
		p2->input();
		p2->next=p1;
		p->next=p2;
		cout<<"选择是否插入：(Y/N)"<<endl;
		cin>>k;
	}
	system("pause");
}
void  studentmessage::shanchu() {
	system("cls");
	student *p=head;
	student *p1=head->next;
	char k;
	while(k!='N') {
		int n;
		cout<<"输入你删除的位数"<<endl;
		cin>>n;
		int i=0;
		while(n!=i+1) {
			p=p->next;
			p1=p->next;
			i++;
		}
		p->next=p1->next;
		delete p1;
		cout<<"删除成功"<<endl;
		cout<<"选择是否删除：(Y/N)"<<endl;
		cin>>k;


	}
	system("pause");
}
void  studentmessage::chazhao() {
	system("cls");
	student  *p=head->next;

	int  a;
	cout<<"请输入要查找的学生的学号:";
	cin>>a;
	while(p) {
		if(p->num==a) {
			break;
		}
		p=p->next;
	}
	if(!p) {

		cout<<"未找到要查找学生！"<<endl;
		return  ;
	}

	cout<<"查找成功";
	cout<<"-----------------------"<<endl;
	cout<<"学号："<<p->num<<endl;
	cout<<"姓名："<<p->name<<endl;
	cout<<"语文："<<p->score[1]<<endl;
	cout<<"高数："<<p->score[2]<<endl;
	cout<<"英语："<<p->score[3]<<endl;
	cout<<"专业课："<<p->score[4]<<endl;
	cout<<"总分："<<p->total<<endl;
	system("pause");
}
void  studentmessage::maxmin() {
    system("cls");
	student  *p,*q;
	p=head->next;
	for(p; p->next!=NULL; p=p->next) {
		for(q=p->next; q->next!=NULL; q=q->next) {
			if(q->total>p->total)
				swap(q,p);
		}
	}
	cout<<"最高分的名字是:"<<head->next->name<<endl;
	student *p1=head->next;
	//cout<<"最低分的名字是:"<<p1->name<<endl; 
	while(p1->next->next!=NULL)
	{
//		cout<<"最低分的名字是:"<<p1->name<<endl; 
		p1=p1->next;
		
    } 
	 cout<<"最低分的名字是:"<<p1->name<<endl; 
	cout<<"输出成功！"<<endl;
	system("pause");
    
}
void  studentmessage::average() {
	system("cls");

	student  *p=head->next;
	double  average[5];
	int i=0;
	for(p; p!=NULL; p=p->next) {
		average[1]=average[1]+p->score[1];
		average[2]=average[2]+p->score[2];
		average[3]=average[3]+p->score[3];
		average[4]=average[4]+p->score[4];
		i++;
	}

	cout<<"语文平均成绩："<<average[1]/i<<endl;
	cout<<"高数平均成绩："<<average[2]/i<<endl;
	cout<<"英语平均成绩："<<average[3]/i<<endl;
	cout<<"专业课平均成绩："<<average[4]/i<<endl;
	system("pause");
}
void  studentmessage::save() {
	system("cls");
	out.open("file.text");
	student *p=head->next;
	//out<<"1"<<" ";
	if(head->next==NULL) {
		cout<<"没有文件"<<endl;
		return ;
	} else {
		//	out<<"学号:   "<<"姓名:   "<<"语文:  "<<"高数:  "<<"英语:  ""专业课:  "<<"总分:  "<<endl;
		for(p; p->next!=NULL; p=p->next) {
			out<<" ";
			out<<p->num<<" ";
			out<<p->name<<" ";
			out<<p->score[1]<<" ";
			out<<p->score[2]<<" ";
			out<<p->score[3]<<" ";
			out<<p->score[4]<<" ";
			out<<p->total<<endl;
		}
	}
	out.close();
	cout<<"文件保存成功!"<<endl;
	system("pause");
}
void  studentmessage::youxiu() {
	system("cls");
	student *p=head->next;
	for(p; p!=NULL; p=p->next) {
		if(p->total>340&&p->score[1]>70&&p->score[2]>70&&p->score[3]>70&&p->score[4]>70) {
			cout<<"-----------------------"<<endl;
			cout<<"学号："<<p->num<<endl;
			cout<<"姓名："<<p->name<<endl;
			cout<<"语文："<<p->score[1]<<endl;
			cout<<"高数："<<p->score[2]<<endl;
			cout<<"英语："<<p->score[3]<<endl;
			cout<<"专业课："<<p->score[4]<<endl;
			cout<<"总分："<<p->total<<endl;
			cout<<"------------------------"<<endl;
			continue;
		}

	}
	system("pause");
}
void  studentmessage::bukao() {
	system("cls");
	student *p=head->next;
	out.open("bukao.text");
	out<<"补考名单："<<endl;
	for(p; p!=NULL; p=p->next) {
		if(p->score[1]<60||p->score[2]<60||p->score[3]<60||p->score[4]<60) {
			out<<p->name<<endl;;
			continue;
		}
	}
	out.close();
	cout<<"文件保存成功！"<<endl;

	system("pause");
}
class teather :public studentmessage {


	public:
		//	teather();
		void  menu();

};
void teather::menu() {

	system("cls");
	system("date/t");
	system("time/t");
	system("color 5F");
	cout<<"\t\t\t\t***************************************************"<<endl;
	cout<<"\t\t\t\t-------------------老师管理系统--------------------"<<endl;
	cout<<"\t\t\t\t                    1.录入信息                     "<<endl;
	cout<<"\t\t\t\t                    2.显示信息                     "<<endl;
	cout<<"\t\t\t\t                    3.修改信息                     "<<endl;
	cout<<"\t\t\t\t                    4.删除信息                     "<<endl;
	cout<<"\t\t\t\t                    5.添加信息                     "<<endl;
	cout<<"\t\t\t\t                    6.查找信息                     "<<endl;
	cout<<"\t\t\t\t                    7.总分排序                     "<<endl;
	cout<<"\t\t\t\t                    8.平均成绩                     "<<endl;
	cout<<"\t\t\t\t                    9.优秀名单                     "<<endl;
	cout<<"\t\t\t\t                    10.保存信息                    "<<endl;
	cout<<"\t\t\t\t                    11.最大最小                    "<<endl;
	cout<<"\t\t\t\t                    12.补考名单                    "<<endl;
	cout<<"\t\t\t\t                    13.退出系统                    "<<endl;
	cout<<"\t\t\t\t***************************************************"<<endl;
	system("pause");
}
class studentstudent:public studentmessage {
	public:
};
int main() {
	cout<<endl<<endl<<endl<<endl<<endl<<endl<<endl<<endl<<endl;
	cout.width(65);
	cout <<"系统正在启动，请稍等！";
	for(int i=0; i<7; i++) {
		printf(" .");
		Sleep(200);
	}
	int flag=1;
	while (flag) {
		system("cls");
		system("date/t");
		system("time/t");
		system("color 3F");
		cout<<"\t\t\t\t---------------------------------------\t\t\t\t"<<endl;
		cout<<"\t\t\t\t--------欢迎来到学生信息管理系统-------\t\t\t\t"<<endl;
		cout<<"\t\t\t\t---------------1.老师管理--------------\t\t\t\t"<<endl;
		cout<<"\t\t\t\t---------------2.学生管理--------------\t\t\t\t"<<endl;
		cout<<"\t\t\t\t---------------3.退出系统--------------\t\t\t\t"<<endl;
		cout<<"\t\t\t\t---------------------------------------\t\t\t\t"<<endl;
		int i;
		cout<<"请选择(1,2,3)"<<endl;
		cin>>i;
		if(i==1) {

			teather m;
			int flag1=1;
			while(flag1) {
				m.menu();
				cout<<"你选择的编号："<<endl;
				int n;
				cin>>n;
				switch(n) {
					case 1:
						system("cls");
						m.add();
						break;
					case 2:
						system("cls");
						m.display();
						break;
					case 3:
						system("cls");
						m.xiugai();
						break;
					case 4:
						system("cls");
						m.shanchu();
						break;
					case 5:
						system("cls");
						m.tianjia();
						break;
					case 6:
						system("cls");
						m.chazhao();
						break;
					case 7:
						system("cls");
						m.rank();
						break;
					case 8:
						system("cls");
						m.average();
						break;
					case 9:
						system("cls");
						m.youxiu();
						break;
					case 10:
						system("cls");
						m.save();
						break;
					case 11:
						system("cls");
						m.maxmin();
						break;
					case 12:
						system("cls");
						m.bukao();
						break;
					case 13:
						system("cls");
						flag1=0;
						break;
				}

			}
		}

		if(i==2) {

			studentstudent w;
			int flag2=1;
			while(flag2) {
				w.menu();
				cout<<"你选择的编号："<<endl;
				int n;
				cin>>n;
				switch(n) {
					case 1:
						system("cls");
						w.add();
						break;
					case 2:
						system("cls");
						w.display();
						break;
					case 3:
						system("cls");
						w.xiugai();
						break;
					case 4:
						system("cls");
						w.shanchu();
						break;
					case 5:
						system("cls");
						w.tianjia();
						break;
					case 6:
						system("cls");
						w.chazhao();
						break;
					case 7:
						system("cls");
						w.save();
						break;
					case 8:
						system("cls");
						flag2=0;
						break;
				}

			}
		}
		if(i==3) {
			system("cls");
			cout<<"欢迎下次再来"<<endl;
			flag=0;
			system("pause");
		} else {
			system("cls");
			cout<<"欢迎来到主页面"<<endl;
			system("pause");
		}
	}
	return 0;
}

6) 案例六

#include<iostream>
#include<cstring>
#include<stdlib.h>
#include<fstream>

using namespace std;

class Student{
	public:
		int id;
		char name[20];
		char sex[20];
		int age;
		int score;
};

class operate:public Student{
	public:
		int n;
		operate(int score1)
		{
			score=score1;
		} 
		operate *next;
		operate *creat(operate *head);
		void add(operate *head);
		void del(operate *head);
		void search(operate *head);
		void rewrite(operate *head);
		void show(operate *head);
		void sort(operate *head);
		int save(operate *head);
		void read(operate *head);
		void headline();
};


//void operate::save(operate *head)
//{
//	ofstream outfile("D:\\a.txt");
//	if(!outfile)
//	{
//		cerr<<"open error!"<<endl;
//		exit(1);
//	}
//	operate *p=head->next;
//	while(p)
//	{
//		outfile<<p->score<<endl	;
//		p=p->next;
//	}
//	outfile.close();
//	cout<<"保存完成"<<endl; 
//}

int  operate::save(operate *head)
{
	operate *p=head->next;
	fstream outfile("D:\\a.txt",ios::out);
	if(!outfile)
	{
		cout<<"File open error"<<endl;
		return -1;
	}
	while(p!=NULL)
	{
		outfile<<p->id<<endl;
		outfile<<p->name<<endl;
		outfile<<p->sex<<endl;
		outfile<<p->age<<endl;
		outfile<<p->score<<endl;
		p=p->next;
	}
	outfile.close();
	cout<<"保存成功"<<endl;
}

void operate::read(operate *head)
{
	fstream infile("D:\\a.txt",ios::in);
	if(!infile)
	{
		cerr<<"read error!"<<endl;
		exit(1);
	}
	operate *p=head->next;
	while(p!=NULL)
	{
		infile>>p->id;
		infile>>p->name;
		infile>>p->sex;
		infile>>p->age;
		infile>>p->score;
		cout<<"id:"<<p->id<<endl;
		cout<<"name:"<<p->name<<endl;
		cout<<"sex:"<<p->sex<<endl;
		cout<<"age:"<<p->age<<endl;
		cout<<"score:"<<p->score<<endl;
		
		p=p->next;
	}
	infile.close();
	cout<<"读取完毕"<<endl;
}


/*void operate::save(operate *head)
{
	FILE *fp;
	operate *p;
	p=head->next;
	if((fp=fopen("stu.txt","a"))==NULL)
	{
		cout<<"error"<<endl;
		return ; 
	}
	while(p!=NULL)
	{
	
		fprintf(fp," %d \n",p->score);
		p=p->next;	
	}
	cout<<"保存成功"<<endl;
	fclose(fp);
}*/

/*void operate::read(operate *head)
{
	FILE *fp;
	operate *pt;
	int i=0;
	
	pt=head->next;
	
	if((fp=fopen("stu.txt","r"))==NULL)
	{
		cout<<"error"; 
		exit(0); 
	}
	fscanf(fp,"%d ",&pt->score);
	
	while(pt!=NULL)    
	{	
		i++;
		cout<<"第"<<i<<"个学生的分数："<<pt->score<<endl;
		pt=pt->next;
	
	}
	
	fclose(fp);
	
}*/


operate *operate::creat(operate *head)
{
			head=(operate *)malloc(sizeof(operate));

			operate *p;
			p=head;
			p->next==NULL;
			int id1;
			char name1[20];
			char sex1[20];
			int age1;
			int score1;
			cout<<"请输入要添加的人数："<<endl;
			cin>>n;
			for(int i=0;i<n;i++)
			{
			
			operate *q=(operate *)malloc(sizeof(operate));
			
			
			cout<<"id："<<endl;
			cin>>id1;
			cout<<"name："<<endl;
			cin>>name1;
			cout<<"sex："<<endl;
			cin>>sex1;
			cout<<"age："<<endl;
			cin>>age1;
			cout<<"score："<<endl;
			cin>>score1;
			q->id=id1;
			strcpy(q->name,name1);
			strcpy(q->sex,sex1);
			q->age=age1;
			q->score=score1;
			p->next=q;
			q->next=NULL;
			p=q;
			}
			return head;
}
void operate::show(operate *head)
{
	
	operate *p;
	p=head->next;
	while(p!=NULL)
	{
		cout<<"id:"<<p->id<<endl;
		cout<<"name:"<<p->name<<endl;
		cout<<"sex:"<<p->sex<<endl;
		cout<<"age:"<<p->age<<endl;
		cout<<"score:"<<p->score<<endl;
		p=p->next;
	}
}

void operate::add(operate *head)
{
	operate *p1,*p2,*p3;
	int b;
	p1=head;
	p3=p1->next;
	int id1;
	cout<<"请输入要插入哪个id后："<<endl;
	cin>>id1;
	
	while (p3!=NULL)
	{
		if(p3->id==id1)
		{
			b=0;
			break;
		}
		
		p3=p3->next;
	}
	if(b==0)
	{
	
	cout<<"请输入要插入的数："<<endl;
	p2=(operate *)malloc(sizeof(operate));
	cin>>p2->id;
	cin>>p2->name;
	cin>>p2->sex;
	cin>>p2->age;
	cin>>p2->score;
	
	p2->next=p3->next;
	p3->next=p2; 
	}
	else{
		cout<<"无此学生"<<endl;
	}
}

void operate::del(operate *head)
{
	operate *p,*q;
	int b=1,d=0;
	q=head;
	p=q->next;							
	cout<<"请输入要删除的id："<<endl;
	int id1;
	cin>>id1;
	while (p->id!=id1) {
	
		q=q->next;
		p=p->next;
		if(p==NULL)
		{
		cout<<"无此学生，删除失败"<<endl;
		b=0;
		break;
		}
	}
	if(b!=0)
	{
	q->next=p->next;
	free(p);
	}
		
}

void operate::search(operate *head)
{
	operate *p,*q;
	int b;
	q=head;
	p=head->next;
	int id1;
	cout<<"请输入要查找的id："<<endl;
	cin>>id1;
	while(p!=NULL)
	{
		if(p->id==id1)
		{
		b=1;
		cout<<"id:"<<p->id<<endl;
		cout<<"name:"<<p->name<<endl;
		cout<<"sex:"<<p->sex<<endl;
		cout<<"age:"<<p->age<<endl;
		cout<<"score:"<<p->score<<endl;
			break;
		}
		else if(b!=1)
		{
			cout<<"无此学生"<<endl;
		}
		q=q->next;
		p=p->next;	
	}
	
} 

void operate::rewrite(operate *head)
{
	operate *p,*q;
	q=head;
	p=head->next;
	int id1;
	cout<<"请输入要修改的id："<<endl;
	cin>>id1;
	while(p!=NULL)
	{
		if(p->id==id1)
		{
			cout<<"请输入修改后的数据："<<endl;
			cin>>p->id;
			cin>>p->name;
			cin>>p->sex;
			cin>>p->age;
			cin>>p->score;
			break;
		}
		q=q->next;
		p=p->next;
		if(q->id!=id1)
		{
		cout<<"无此学生,修改失败！"<<endl;
		break;
		}
	}
	
}


void operate::sort(operate *head)
{
	operate *p,*q,*q1;
	int score1;
	char name_[20];
	char sex_[20];
	int age1;
	int id_;
	q1=head->next;
	int k=0;
	while(q1!=NULL)
	{	
		k++;
		q1=q1->next;
	}
	for(int i=0;i<k;i++)
	{
	for(p=head->next,q=p->next;p!=NULL,q!=NULL;p=p->next,q=q->next)
	{
		if(p->score>q->score)
		{
				score1=q->score;
				q->score=p->score;
				p->score=score1;

				strcpy(name_,q->name);
				strcpy(q->name,p->name);
				strcpy(p->name,name_);

				strcpy(sex_,q->sex);
				strcpy(q->sex,p->sex);
				strcpy(p->sex,sex_);
				
				age1=q->age;
				q->age=p->age;
				p->age=age1;
				
				id_=q->id;
				q->id=p->id;
				p->id=id_;
		}
	}                                                                                                                                                                                              
	}
}

void operate::headline()
{
	printf("     欢迎使用学生信息管理系统     \n");
	printf("=========学生信息管理系统=========\n");
	printf("=         1.录入学生信息         =\n");
	printf("=         2.添加学生信息         =\n");
	printf("=         3.删除学生信息         =\n");
	printf("=         4.查询学生信息         =\n");
	printf("=         5.修改学生信息         =\n");
	printf("=         6.学生成绩排序         =\n");
	printf("=         7.学生成绩储存         =\n");
	printf("=         8.学生成绩读取         =\n");
	printf("=         9.退出系统             =\n");
}




int main() {
	system("color 5F");
	int i;
	operate *head;
	operate a(1);
		do {
			a.headline();

			printf("=    请选择1-8                   =\n");
			printf("==================================\n");
			scanf("%d",&i);
			switch(i) {
				case 1:
					head=a.creat(head);
					a.show(head);
					break;
				case 2:
					a.add(head);
					a.show(head);
					break;
				case 3:
					a.del(head);
					a.show(head);
					break;
				case 4:
					a.search(head);
					break;
				case 5:
					a.rewrite(head);
					a.show(head);
					break;
				case 6:
					a.sort(head);
					a.show(head);
					break;
				case 7:
					a.save(head);
					break;
				case 8:
					a.read(head);
					break;
				case 9:
					break;
				default:
					cout<<"选择错误，请重选！！"<<endl;

			}
			system("pause");
			system("cls");

		} while(i!=9);
	return 0;

}

























//int main()
//{
//	operate *head;
//	operate a(1);
//	head=a.creat(head);
//	a.show(head);
	a.add(head);
	a.show(head);
	a.del(head);
	a.show(head);
	a.search(head);	
	a.rewrite(head);
	a.show(head);
//	a.sort(head);
//	a.show(head);
//	a.save(head);
//	a.read(head);
//	return 0;
//}











/*	int c;
	cout<<"请输入插入方式(1.头插 2.尾插 3.中插)"<<endl;
	cin>>c;
	switch(c)
	{
		case 1:
			operate *p;
			p=(operate *)malloc(sizeof(operate));
			cout<<"输入要插入的分数："<<endl;
			cin>>p->score;
			p->next=head->next;
			head->next=p;
			break;
		case 2:
			operate *p1,*q;
			q=head->next;
			p1=(operate *)malloc(sizeof(operate));
			cout<<"输入要插入的分数："<<endl;
			int score1;
			cin>>score1;
			p1->score=score1;
			while(q!=NULL)
			{
				if(q->score=score1)
				{
					cout<<"已存在的分数，请重新输入。"<<endl;
					break;
				}
				q=q->next;
			}	
		    p1=q->next;
			p1->next=NULL;
			
	}
*/

7) 案例七

//录入其信息，如：学生姓名，性别，专业，出生日期，家庭地址，英语入学成绩
#include<iostream>
#include<string>
//#include<string.h>
#include<fstream>
#include<conio.h>
//#include<windows.h> 
//#include<time.h>

using namespace std;
class student	//信息 
{
	public:
		student(string name,string sex,string major,string birthday,string home,string englishscore);
		student(string zhanghao,string mima);
		string s_name ;			//姓名 
		string s_sex ;			//性别 
		string s_major ;		//专业 
		string s_birthday ;		//生日 
		string s_home ;			//住址 
		string s_englishscore;	//英语成绩
		int i_studentnum;		//学生人数 
		student ** student_p;	//学生指针
		bool panduanwenjian;	//判断文件 
		int getnum();			//得到文件中内用数量 
		void init();			//初始化数据
		void dayin();			//打印 
		int panduanxuesheng(string name);	//判断学生是否存在 
		~student();
};

student::student(string name,string sex,string major,string birthday,string home,string englishscore)
{
	this->s_name=name;
	this->s_sex=sex;
	this->s_major=major;
	this->s_birthday=birthday;
	this->s_home=home;
	this->s_englishscore=englishscore;
	
	this->i_studentnum=0;
	this->student_p=NULL;
}

student::~student()
{
	if(this->student_p!=NULL)
	{
		delete[] this->student_p;
		this->student_p=NULL;
	}
}

class function:public student 	//功能 
{
	public:
		function(string name,string sex,string major,string birthday,string home,string englishscore);
		function(string zhanghao,string mima); 
		void mulu();			//目录
		void tuichu();			//退出 
		void zengjia();			//增加
		void shanchu();			//删除
		void duwenjian();		//读文件 
		void chazhao();			//查找
		void xiugai();			//修改
		void xianshi();			//显示 
		void tongji();			//统计
		void paixu();			//排序
		void cunwenjian();		//存文件
		~function(){};
};

function::function(string name,string sex,string major,string birthday,string home,string englishscore):student(name,sex,major,birthday,home,englishscore)
{
	
}

void function::zengjia()			//增加
{
	cout<<"请输入要添加的学生数"<<endl;
	int addnum;
	cin>>addnum;
	if(addnum>0)
	{
		int newsize=this->i_studentnum+addnum;
		student ** newspace=new student * [newsize];
		if(this->student_p!=NULL)
		{
			for(int i=0;i<this->i_studentnum;i++)
			{
				newspace[i]=this->student_p[i];
			}
		}
		for(int i=0;i<addnum;i++)
		{
			string name,sex,major,birthday,home,englishscore;
			
			cout<<"请输入第"<<i+1<<"个新学生姓名"<<endl;
			cin>>name;
			
			cout<<"请输入第"<<i+1<<"个新学生性别"<<endl;
			cin>>sex;
			
			cout<<"请输入第"<<i+1<<"个新学生专业"<<endl;
			cin>>major;
			
			cout<<"请输入第"<<i+1<<"个新学生生日"<<endl;
			cin>>birthday;
			
			cout<<"请输入第"<<i+1<<"个新学生住址"<<endl;
			cin>>home;
			
			cout<<"请输入第"<<i+1<<"个新学生英语成绩"<<endl;
			cin>>englishscore;
			student * stu=NULL;
			stu=new student(name,sex,major,birthday,home,englishscore);
			newspace[this->i_studentnum+i]=stu;
		}
		delete [] this->student_p;
		this->student_p=newspace;
		this->i_studentnum=newsize;
		this->panduanwenjian=false; 
		cout<<"成功添加"<<addnum<<"名学生"<<endl;
	}
	else
	{
		cout<<"输入有误"<<endl;
	}
	system("pause");
	system("cls");
} 

void function::shanchu()			//删除
{
	if(this->panduanwenjian)
	{
		cout<<"文件不存在或为空！"<<endl;
	}
	else
	{
		cout<<"请输入要删除的姓名："<<endl;
		string name;
		cin>>name;
		int index=this->panduanxuesheng(name);
		if(index!=-1)
		{
			for(int i=index;i<this->i_studentnum-1;i++)
			{
				this->student_p[i]=this->student_p[i+1];
			}
			this->i_studentnum--;
			this->cunwenjian();
			cout<<"删除成功！"<<endl;
		}
		else
		{
			cout<<"删除失败，未找到该学生"<<endl;
		 } 
	}
	system("pause");
	system("cls");
} 

void function::duwenjian()			//读文件 
{
	ifstream ifs;
	ifs.open("wenjian.txt",ios::in);
	if(!ifs.is_open())
	{
		cout<<"文件不存在"<<endl;
		this->i_studentnum=0;
		this->panduanwenjian=true;
		this->student_p=NULL;
		ifs.close();
		system("pause");
		system("cls");
		return ;		
	}
	char ch;
	ifs>>ch;
	if(ifs.eof())
	{
		cout<<"文件为空"<<endl;
		this->i_studentnum=0;
		this->panduanwenjian=true;
		this->student_p=NULL;
		ifs.close();
		system("pause");
		system("cls");
		return ;
	}
	
	int num=this->getnum();
//	cout<<"文件中学生数为："<<num<<endl;	//测试
//	system("pause");
	this->i_studentnum=num;

	this->student_p=new student * [this->i_studentnum];
	init();
//	for(int i=0;i<i_studentnum;i++)			//测试 
//	{
//		cout<<"姓名："<<this->student_p[i]->s_name<<endl;
		system("pause");
//	}
}

void function::chazhao()			//查找
{
	if(this->panduanwenjian)
	{
	 	cout<<"文件不存在或为空！"<<endl;
	}
	else
	{
		cout<<"请输入要查找的学生姓名："<<endl;
		string name;
		cin>>name;
		bool flag=false;
		for(int i=0;i<i_studentnum;i++)
		{
			if(student_p[i]->s_name==name)
			{
				cout<<"查找成功，信息如下："<<endl;
				flag=true;
				this->student_p[i]->dayin();
			}
		}
		if(flag==false)
		{
			cout<<"查找失败，查无此人"<<endl;
		}
	}
	system("pause");
	system("cls");
}

void function::xiugai()			//修改
{
	if(this->panduanwenjian)
	{
		cout<<"文件不存在或为空！"<<endl;
	}
	else
	{
		cout<<"请输入要修改的学生的姓名："<<endl;
		string name;
		cin>>name;
		int ret=this->panduanxuesheng(name);
		if(ret!=-1)
		{
			delete this->student_p[ret];
			string newname="";
			string newsex="";
			string newmajor="";
			string newbirthday="";
			string newhome="";
			string newenglishscore="";
			cout<<"查到"<<name<<"同学请输入新姓名："<<endl;
			cin>>newname;
			cout<<"请输入新性别："<<endl;
			cin>>newsex;
			cout<<"请输入新专业："<<endl;
			cin>>newmajor;
			cout<<"请输入新生日："<<endl;
			cin>>newbirthday;
			cout<<"请输入新住址："<<endl;
			cin>>newhome;
			cout<<"请输入新英语成绩："<<endl;
			cin>>newenglishscore;
			student * stu=NULL;
			stu=new student(newname,newsex,newmajor,newbirthday,newhome,newenglishscore);
			this->student_p[ret]=stu;
			cout<<"修改成功！"<<endl; 
		}
		else
		{
			cout<<"修改失败，查无此人！"<<endl;
		}
	}
	system("pause");
	system("cls");
}

void function::xianshi()		//显示
{
	if(this->panduanwenjian)
	{
		cout<<"文件不存在或为空!"<<endl;
	}
	else
	{
		for(int i=0;i<i_studentnum;i++)
		{
			this->student_p[i]->dayin();
		}
	}
	system("pause");
	system("cls");
}

void function::tongji()			//统计
{
	 if(this->panduanwenjian)
	{
		cout<<"文件不存在或为空!"<<endl;
	}
	else
	{	
		int a1=0,a2=0;
		for(int i=0;i<i_studentnum;i++)
		{
			if(this->student_p[i]->s_sex=="男")
			{
			 	a1++;
			}
			else
			{
				a2++;
			}
		}
		cout<<"男生人数："<<a1<<endl; 
		cout<<"女生人数："<<a2<<endl;
	}
	system("pause");
	system("cls");
}

void function::paixu()			//排序
{
	if(this->panduanwenjian)
	{
		cout<<"文件不存在或为空!"<<endl;
	}
	else
	{
		for(int i=0;i<i_studentnum;i++)
		{
			int max=i;
			for(int j=i+1;j<i_studentnum;j++)
			{
				if(student_p[max]->s_englishscore<student_p[j]->s_englishscore)
				{
					max=j;
				}
			}
			if(i!=max)
			{
				student * temp=student_p[i];
				student_p[i]=student_p[max];
				student_p[max]=temp;
			}
		}
		cout<<"排序成功，结果为："<<endl;
		this->cunwenjian();
		this->xianshi();
	}	
}

void function::cunwenjian()		//存文件
{
	ofstream ofs;
	ofs.open("wenjian.txt",ios::out);
	for(int i=0;i<this->i_studentnum;i++)
	{
		ofs<<this->student_p[i]->s_name<<" "<<this->student_p[i]->s_sex<<" "<<this->student_p[i]->s_major<<" "<<this->student_p[i]->s_birthday<<" "<<this->student_p[i]->s_home<<" "<<this->student_p[i]->s_englishscore<<endl;
	}
	ofs.close();
}

void student::dayin()			//打印 
{
	cout<<"姓名："<<this->s_name<<"\t性别："<<this->s_sex<<"\t专业："<<this->s_major<<"\t生日："<<this->s_birthday<<"\t住址："<<this->s_home<<"\t英语成绩："<<this->s_englishscore<<endl; 
}

int student::getnum() 			//得文件中学生数量 
{
	ifstream ifs;
	ifs.open("wenjian.txt",ios::in);
	int num=0;
	string s_name ;			//姓名 
	string s_sex ;			//性别 
	string s_major ;		//专业 
	string s_birthday ;		//生日 
	string s_home ;			//住址 
	string s_englishscore;		//英语成绩
	while(ifs >> s_name && ifs >> s_sex && ifs >> s_major && ifs >> s_birthday && ifs >> s_home && ifs >> s_englishscore) 
	{
		num++;
	}
	ifs.close();
	return num;
}

void student::init()			//初始化 
{
	ifstream ifs;
	ifs.open("wenjian.txt",ios::in);
	string s_name ;			//姓名 
	string s_sex ;			//性别 
	string s_major ;		//专业 
	string s_birthday ;		//生日 
	string s_home ;			//住址 
	string s_englishscore;	//英语成绩
	int index=0;
	while(ifs >> s_name && ifs >> s_sex && ifs >> s_major && ifs >> s_birthday && ifs >> s_home && ifs >> s_englishscore)
	{
		student * stu=NULL;
		stu=new student(s_name,s_sex,s_major,s_birthday,s_home,s_englishscore);
		this->student_p[index]=stu;
		index++;
	}
	ifs.close();
}

int student::panduanxuesheng(string name)	//判断学生 
{
	int index=-1;
	for(int i=0;i<this->i_studentnum;i++)
	{
		if(this->student_p[i]->s_name==name)
		{
			index=i;
			break;
		}
	}
	return index;
}

void function::mulu()	//目录 
{
	cout<<"**************************************"<<endl;
	cout<<"*****欢迎使用新生基本信息统计软件*****"<<endl;
	cout<<"\t1. 学生信息新增\t"<<endl;
	cout<<"\t2. 学生信息删除\t"<<endl;
	cout<<"\t3. 学生信息导入\t"<<endl;
	cout<<"\t4. 学生信息搜索\t"<<endl;
	cout<<"\t5. 学生信息修改\t"<<endl;
	cout<<"\t6. 学生信息显示\t"<<endl;
	cout<<"\t7. 学生信息统计(男/女)\t"<<endl;
	cout<<"\t8. 按英语成绩排序\t"<<endl;
	cout<<"\t9. 学生信息保存\t"<<endl;
	cout<<"\t0. 退出\t"<<endl;
	cout<<"**************************************"<<endl;
	cout<<endl;
}

void function::tuichu()	//退出 
{
	cout<<"--------------------"<<endl;
	cout<<"谢谢使用"<<endl;
	system("pause");
	exit(0);
}

struct user{
		string password;
		string name;
	};

void zhuce()		//注册 
{
	system("cls");
	string name;
	char *password = new char[20];
	
	
	user c;
	ifstream fin;
	fin.open("user.txt",ios::in); 
	cout<<"请输入用户名：";
	cin>>name;
	while(fin>>c.name>>c.password)
	{
		if(name==c.name)
		{
			cout<<"该用户名已被占用"<<endl;
			system("pause");
			zhuce();
		}
	}
	char test;
	int i=0;
	cout<<"输入密码：";
	while((test=getch())!='\r')
	{
		if(test==0)
		{
			if(i>0)
			{
				cout<<test<<" "<<test;
				password[i--]='\0';
			}
		}
		else
		{
			if(i<20)
			{
				cout<<"*";
				password[i]=test;
				i++;
			}
		}
	}
	password[i]='\0';
	cout<<endl<<"再次输入密码：";
	char *password2=new char[20];
	i=0;
	while((test=getch())!='\r')
	{
		if(test==0)
		{
			if(i>0)
			{
				cout<<test<<" "<<test;
				password2[i--]='\0';
			}
		}
		else
		{
			if(i<20)
			{
				cout<<"*";
				password2[i]=test;
				i++;
			}
		}
		password2[i]='\0';
	}
	if(password==password2)
	{
		cout<<endl<<"两次密码不正确"<<endl;
		system("pause");
		zhuce();
	}
	else
	{
		cout<<endl<<"注册成功"<<endl;
		system("pause"); 
	}
	ofstream fout;
	fout.open("user.txt",ios_base::out|ios_base::app);
	fout<<name<<" "<<password<<endl;
	fout.close();
}

void denglu()		//登录 
{
	system("cls");
	char * password=new char[20];
	string name;
	cout<<"用户名：";
	cin>>name;
	cout<<"密码：";
	char test;
	int i=0;
	while((test=getch())!='\r')
	{
		if(test==0)
		{
			if(i>0)
			{
				cout<<test<<" "<<test;
				password[i--]='\0';
			}
		}
		else
		{
			if(i<20)
			{
				cout<<"*";
				password[i]=test;
				i++;
			}
		}
	}
	password[i]='\0';
	ifstream fin;
	fin.open("user.txt",ios_base::in);
	if(fin.fail())
	{
		cout<<"文件打开失败！"<<endl;
	}
	user c;
	int f1;
	while(fin>>c.name>>c.password)
	{
		if(c.name==name&&c.password==password)
		{
			cout<<endl<<"登陆成功"<<endl;
			system("pause"); 
			f1=1;
//			ntreface();
		}
	}
	if(f1==0)
	{
		cout<<"用户名或密码错误"<<endl;
		system("pause");
		denglu();
//		logo();
	}
}

void dengluzhuce()	//登陆注册 
{
	while(1)
	{
	system("cls");
	system("color 0b");
	cout<<"*********欢迎使用新生基本信息统计软件*********"<<endl;
	cout<<"\t\t1.登录\t\t"<<endl;
	cout<<"\t\t2.注册\t\t"<<endl;
	cout<<"\t\t3.退出\t\t"<<endl;
	
	int a;
	cin>>a;
	switch(a)
	{
		case 1:
			denglu();
			return ;
			break;
		case 2:
			zhuce();
			break;
		case 3:
			exit(0);
			break;
		default:
			break;
	}	
	}

}

int main()
{
	system("mode con cols=50 lines=25");
	dengluzhuce();
	function p1("0","0","0","0","0","0");
	int a=1;
	while(a)
	{
		system("color 07"); 
		system("cls");
		p1.mulu();
		int b;
		cin>>b;
		switch(b)
		{
			case 1://新增学生信息
				p1.zengjia();
				break;
			case 2://删除学生信息
				p1.shanchu();
				break;
			case 3://导入学生信息(读取文件)
				p1.duwenjian(); 
				break;
			case 4://学生信息搜索 (按姓名)
				p1.chazhao();
				break;
			case 5://修改 
				p1.xiugai();
				break;
			case 6://显示
				p1.xianshi(); 
				break;
			case 7://学生信息统计(按专业或性别或年龄)
				p1.tongji();
				break;
			case 8://按英语成绩排序
				p1.paixu();
				break;
			case 9://学生信息保存(入文件)
				p1.cunwenjian();
				break;
			case 0://退出
				p1.tuichu();
				break;
			default:
				cout<<"指令错误！"<<endl;
				system("pause");
				system("cls");
				break;
		}
	}
	return 0;
}

8) 案例八

#include<iostream>
#include<string>
#include<fstream>
#include<stdlib.h>
#include<windows.h>
using namespace std;
class student {
	public:
		int num;
		char name[20];
		float chi;
		float eng;
		float math;
		float syn;
		float total;
		float paiming;
		student *next;
};
class operate:public student {
	private:
		student*head;
		student*p;
	public:
		operate();
		void paixu();
		void shuchuzongfen();
		void conserve();
		void input();
		void maxmin();
		void duqu();
		void zongfendanke();
		void gekepingjunfen();
		void bukao();
		void del();
		void add();
		void find();
		void change();
};
operate::operate() { //创建头结点
	head=new student;
	head->next=NULL;
	p=head;
}

void operate::input() {
	p=head;
	student*q;
	int temp;
	cout<<"请输入输入学生人数"<<endl;
	cin>>temp;
	for(int i=0; i<temp; i++) {
		q=new student;
		cout<<"\n请输入学生信息：\n"<<endl;
		cout<<"学号："<<endl;
		cin>>q->num;
		cout<<"姓名："<<endl;
		cin>>q->name;
		cout<<"语文："<<endl;
		cin>>q->chi;
		cout<<"数学："<<endl;
		cin>>q->math;
		cout<<"英语："<<endl;
		cin>>q->eng;
		cout<<"综合："<<endl;
		cin>>q->syn;
		q->total=q->chi+q->eng+q->math+q->syn;
		cout<<"总分："<<q->total<<endl;
		p->next=q;
		p=p->next;
	}
	q->next=NULL;
	cout<<"\n******************录入成功*******************\n";
	cout<<"按任意键继续..."<<endl;
	system("pause");
	system("cls");
}

void operate::add() {
	student*q,*s,*p;
	p=head;
	s=p->next;
	q=new student;
	cout<<"\n请输入学生信息：\n"<<endl;
	cout<<"学号："<<endl;
	cin>>q->num;
	cout<<"姓名："<<endl;
	cin>>q->name;
	cout<<"语文："<<endl;
	cin>>q->chi;
	cout<<"数学："<<endl;
	cin>>q->math;
	cout<<"英语："<<endl;
	cin>>q->eng;
	cout<<"综合："<<endl;
	cin>>q->syn;
	q->total=q->chi+q->eng+q->math+q->syn;
	cout<<"总分："<<q->total<<endl;
	p->next=q;
	q->next=s;
	cout<<"\n******************添加成功*******************\n";
	cout<<"按任意键继续..."<<endl;
	system("pause");
	system("cls");
}

void operate::del() {
	p=head;
	student*q;
	int delnum;
	cout<<"输入要删除的学生学号"<<endl;
	cin>>delnum;
	while(p->next!=NULL) {
		q=p->next;
		if(delnum==q->num) {
			p->next=q->next;
			delete q;
		} else {
			p=p->next;
		}
	}
	cout<<"删除成功"<<endl;
	system("pause");
	system("cls");
}

void operate::find() {
	p=head;
	int findnum;
	cout<<"请输入查询的学生学号"<<endl;
	cin>>findnum;
	while(p->next!=NULL) {
		if(p->next->num==findnum) {
			cout<<"姓名："<<p->next->name<<endl;
			cout<<"学号："<<p->next->num<<endl;
			cout<<"语文："<<p->next->chi<<endl;
			cout<<"数学："<<p->next->math<<endl;
			cout<<"英语："<<p->next->eng<<endl;
			cout<<"综合："<<p->next->syn<<endl;
			cout<<"总分："<<p->next->total<<endl;
			cout<<"排名："<<p->next->paiming<<endl;
			break;
		}
		p=p->next;
		if(p->next==NULL) {
			cout<<"查无此人"<<endl;
		}
	}
	system("pause");
}

void operate::change() {
	p=head;
	int ID;
	cout<<"请输入要修改的学生学号"<<endl;
	cin>>ID;
	while(p->next!=NULL) {
		if(p->next==NULL) {
			cout<<"查无此人"<<endl;
		}
		if(p->next->num==ID) {
			cout<<"请输入姓名："<<endl;
			cin>>p->next->name;
			cout<<"请输入学号："<<endl;
			cin>> p->next->num;
			cout<<"请输入语文成绩："<<endl;
			cin>>p->next->chi;
			cout<<"请输入数学成绩："<<endl;
			cin>>p->next->math;
			cout<<"请输入英语成绩："<<endl;
			cin>>p->next->eng;
			cout<<"请输入综合成绩："<<endl;
			cin>>p->next->syn;
			p->next->total =p->next->math +p->next->eng +p->next->chi+p->next->syn;
			cout<<"总成绩："<<p->next->total<<endl;
		}
		p=p->next;

	}
	cout<<"修改学生信息完毕"<<endl;
	system("pause");
	system("CLS");
}

void operate::paixu() {
	student *q;
	p=head;
	int n=0;
	int a;
	char b[20];
	int i,j;
	while(p->next) {
		p=p->next ;
		n++;
		p->paiming=n;
	}
	for(i=0; i<n-1; i++) {
		q=head->next;
		p=q->next;
		for(j=0; j<n-i-1; j++) {
			if(p->total>q->total ) {
				a=q->num ;
				q->num =p->num ;
				p->num =a;

				a=q->chi;
				q->chi=p->chi;
				p->chi=a;

				a=q->math ;
				q->math =p->math ;
				p->math =a;

				a=q->eng ;
				q->eng =p->eng ;
				p->eng =a;

				a=q->syn;
				q->syn =p->syn ;
				p->syn=a;

				a=q->total;
				q->total =p->total ;
				p->total =a;

				strcpy(b,q->name);
				strcpy(q->name ,p->name );
				strcpy(p->name,b);
			}
			p=p->next;
			q=q->next;
		}
	}
}

void operate::shuchuzongfen() {
	p=head;
	student*q=p->next;
	int n=0;
	cout<<"排名"<<"\t"<<"学号"<<"\t"<<"姓名"<<"\t"<<"语文"<<"\t"<<"数学"<<"\t"<<"英语"<<"\t"<<"综合"<<"\t"<<"总分"<<endl;
	while(q!=NULL) {
		cout<<q->paiming<<"\t"<<q->num<<"\t"<<q->name<<"\t"<<q->chi<<"\t"<<q->math<<"\t"<<q->eng<<"\t"<<q->syn<<"\t"<<q->total<<endl;
		q=q->next;
	}
	cout<<"输出完毕"<<endl;
	system("pause");
	system("cls");
}

void operate::conserve() {
	p=head;
	ofstream outfile;       // 定义输出文件流 outfile
	outfile.open("学生信息.txt",ios::out|ios::app);
	while(p->next!=NULL) {
		outfile<<"学号:"<<p->next->num<<" ";
		outfile<<"姓名:"<<p->next->name<<" ";
		outfile<<"语文:"<<p->next->chi<<" ";
		outfile<<"英语:"<<p->next->eng<<" ";
		outfile<<"数学:"<<p->next->math<<" ";
		outfile<<"综合:"<<p->next->syn<<" ";
		outfile<<"总分:"<<p->next->total<<" ";
		outfile<<"排名:"<<p->next->paiming<<" ";
		outfile<<"\n";
		p=p->next;
	}
	outfile.close();
	cout<<"保存学生信息成功"<<endl;
	system("pause");
	system("cls");

}

void operate::maxmin() {
	p=head;
	cout<<"分数最高的学生："<<p->next->name<<endl;
	while(p->next!=NULL) {
		p=p->next;
	}
	cout<<"分数最低的学生："<<p->name<<endl;
	cout<<"输出完毕"<<endl;
	system("pause");
	system("cls");
}

void operate::duqu() {
	ifstream infile;
	infile.open("学生信息.txt",ios::in);
	p=head;
	cout<<"排名"<<"\t"<<"学号"<<"\t"<<"姓名"<<"\t"<<"语文"<<"\t"<<"数学"<<"\t"<<"英语"<<"\t"<<"综合"<<"\t"<<"总分"<<endl;
	while(p->next!=NULL) {
		cout<<p->next->paiming<<"\t"<<p->next->num<<"\t"<<p->next->name<<"\t"<<p->next->chi<<"\t"<<p->next->math<<"\t"<<p->next->eng<<"\t"<<p->next->syn<<"\t"<<p->next->total<<endl;
		p=p->next;
	}
	infile.close();
	cout<<"输出完毕"<<endl;
	system("pause");
	system("cls");
}

void operate::zongfendanke() {
	p=head->next;
	while(p!=NULL) {
		if(p->total>=340&&p->chi>=80&&p->math>=80&&p->eng>=80&&p->syn>=80) {
			cout<<"总分在340分，单科成绩不低于80分的学生:"<<p->name<<endl;
		}
		p=p->next;
	}
	cout<<"输出完毕"<<endl;
	system("pause");
	system("cls");
}

void operate::gekepingjunfen() {
	p=head;
	int n=0;
	float a=0,b=0,c=0,d=0;
	float e,f,g,h;
	while(p!=NULL) {
		n++;
		a=p->chi+a;
		b=p->math+b;
		c=p->eng+c;
		d=p->syn+d;
		p=p->next;
	}
	e=a/(n-1);
	f=b/(n-1);
	g=c/(n-1);
	h=d/(n-1);
	cout<<"语文平均分："<<e<<endl;
	cout<<"数学平均分："<<f<<endl;
	cout<<"英语平均分："<<g<<endl;
	cout<<"综合平均分: "<<h<<endl;
	cout<<"输出完毕"<<endl;
	system("pause");
	system("cls");
}

void operate::bukao() {
	p=head->next;
	ofstream outfile; // 定义输出文件流 outfile
	outfile.open("补考名单.txt",ios::out|ios::app);
	while(p!=NULL) {
		if(p->chi<60&&p->math<60&&p->eng<60&&p->syn<60) {
			cout<<"补考学生名单:"<<p->name<<endl;
			outfile<<"姓名："<<p->name<<"\n";
		}
		p=p->next;
	}
	outfile.close();
	cout<<"输出完毕，已存入文件"<<endl;
	system("pause");
	system("cls");
}

int menu() {
	cout<<"    **********************************  \n"<<endl;
	cout<<"       ***********目录************\n"<<endl;
	cout<<"              输入学生信息：1\n"<<endl;
	cout<<"              增加学生信息：2\n"<<endl;
	cout<<"              删除学生信息：3\n"<<endl;
	cout<<"              查询学生信息：4\n"<<endl;
	cout<<"              修改学生信息：5\n"<<endl;
	cout<<"              保存学生信息：6\n"<<endl;
	cout<<"              读取学生信息：7\n"<<endl;
	cout<<"        输出总分最高及最低学生：8\n"<<endl;
	cout<<"总分在340分，单科成绩不低于80分学生名单：9\n"<<endl;
	cout<<"           求出各科平均分数：10\n"<<endl;
	cout<<"             按总分排名：11\n"<<endl;
	cout<<"        输出补考名单并存入文件：12\n"<<endl;
	cout<<"              退出程序：13\n"<<endl;
	cout<<"    ********************************** \n"<<endl;
}

int main() {
	system("color f5");
	int m;
	operate x;
	while(1) {
		menu();
		cin>>m;
		switch(m) {
			case 1:
				x.input();
				break;
			case 2:
				x.add();
				break;
			case 3:
				x.del();
				break;
			case 4:
				x.paixu();
				x.find();
				break;
			case 5:
				x.change();
				break;
			case 6:
				x.paixu();
				x.conserve();
				break;
			case 7:
				x.duqu();
				break;
			case 8:
				x.paixu();
				x.maxmin();
				break;
			case 9:
				x.zongfendanke();
				break;
			case 10:
				x.gekepingjunfen();
				break;
			case 11:
				x.paixu();
				x.shuchuzongfen();
				break;
			case 12:
				x.bukao();
				break;
			case 13:
				cout<<"欢迎下次使用"<<endl;
				return 0;
				break;
		}
	}

}

9) 案例九

#include<iostream>
#include<fstream>
#include<iomanip>
#include<cstring>
#include<stdlib.h>
#include<windows.h>
#include<conio.h>
using namespace std;
int n=0;
char stop[12]= {"0"};
char name[12];
class Student {
	public:
		int id; 
		char name[12];
		char sex[3];
		char major[20];
		char addr[30];
		char year[5];
		char month[3];
		char day[3];
		int engli;
		char remark[100];
		Student *next;
};

class Utils{
	public:
		virtual Student *add(Student *head)=0;
	 	virtual Student *delet(Student *head)=0;
		virtual void *search(Student *head)=0;
		virtual Student *modify(Student *head)=0;		
};

class information : public Utils {
	private:
		Student *head,*p1,*p2,*p3;
	public:
		information(){};
		Student *creat();
		Student *add(Student *head);
		Student *delet(Student *head);
		void *search(Student *head);
		Student *modify(Student *head);
		Student *sort(Student*head);
		Student *statistics(Student*head);
		void display(Student *head);
		void displaynode(Student *head);
		void write_file(Student *head);
		Student * read_file();
		~information () {};
};

class manage {
	public:
		char menu_manager();
		char menu_user();
		int choose_manager();
		int choose_user(Student *head);
};
information s;
Student *information::creat() {
	p1=p2=new Student;
	head=NULL;
	char sex1[3];
	char sex2[3];
	strcpy(sex1, "男");
	strcpy(sex2, "女");
	cout<<"请输入学生的基本信息：以姓名为0结束。\n";
	while(1) {
		cout<<"姓名:  \t";
		cin>>p1->name;
		if( strcmp(stop,p1->name)==0 ) {
			break;
		}
		cout<<"学号:  \t";
		cin>>p1->id;
		cout<<"性别:  \t";
		cin>>p1->sex;
		while(strcmp(sex1,p1->sex)!=0 &&strcmp(sex2,p1->sex)!=0 ) {
			cout<<"请输入格式  男/女，请重新输入！"<<endl;
			cout<<"性别:  \t";
			cin>>p1->sex;
		}
		cout<<"专业:  \t";
		cin>>p1->major;
		cout<<"家庭住址:  \t";
		cin>>p1->addr;
		cout<<"出生年:";
		cin>>p1->year;
		cout<<"出生月:";
		cin>> p1->month;
		cout<<"出生日:";
		cin>>p1->day;
		cout<<"英语:";
		cin>>p1->engli;
		while(p1->engli<0 || p1->engli>100) {
			cout<<"英语成绩必须在0-100之间，请重新输入！"<<endl;
			cout<<"英语:";
			cin>>p1->engli;
		}
		cout<<"备注:";
		cin>>p1->remark;
		system("cls");
		n=n+1;
		if(n==1)
			head=p1;
		else
			p2->next=p1;
		p2=p1;
		p1=new Student;
	}
	p2->next=NULL;
	return head;
}
Student *information::statistics(Student*head) {
	p1=new Student;
	p1=head;
	int x=0,y=0;
	char sex1[3];
	char sex2[3];
	strcpy(sex1, "男");
	strcpy(sex2, "女");
	for(p1=head; p1!=NULL; p1=p1->next) {
		if(strcmp(sex1,p1->sex)==0 ) {
			x=x+1;
		}
		if(strcmp(sex2,p1->sex)==0) {
			y=y+1;
		}
	}
	cout<<"男:      "<<x<<endl;
	cout<<"女:      "<<y<<endl;
	return head;
}

Student *information::add(Student *head) {
	p1=p3=new Student;
	p1=head;
	char sex1[3];
	char sex2[3];
	strcpy(sex1, "男");
	strcpy(sex2, "女");
	if(p1==NULL) {
		cout<<"在添加前，先新建!"<<endl;
		return 0;
	} else {
		cout<<"请输入要添加学生的信息！\n";
		cout<<"姓名:  \t";
		cin>>p3->name;
		cout<<"学号:  \t";
		cin>>p3->id;
		cout<<"性别:  \t";
		cin>>p3->sex;
		while(strcmp(sex1,p3->sex)!=0 &&strcmp(sex2,p3->sex)!=0 ) {
			cout<<"请输入格式  男/女，请重新输入！"<<endl;
			cout<<"性别:  \t";
			cin>>p3->sex;
		}
		cout<<"专业:  \t";
		cin>>p3->major;
		cout<<"家庭住址:  \t";
		cin>>p3->addr;
		cout<<"出生年:";
		cin>>p3->year;
		cout<<"出生月:";
		cin>> p3->month;
		cout<<"出生日:";
		cin>>p3->day;
		cout<<"英语:";
		cin>>p3->engli;
		while(p3->engli<0 || p3->engli>100) {
			cout<<"英语成绩必须在0-100之间，请重新输入！"<<endl;
			cout<<"英语:";
			cin>>p3->engli;
		}
		cout<<"备注:";
		cin>>p3->remark;
		cout<<"\n";
		p3->next=p1->next;
		p1->next=p3;
		cout<<"添加成功!\n";
	}
	return head;
}

Student *information::delet(Student *head) {
	p2=p1=new Student;
	if(head==NULL) {
		cout<<"没有数据，无法删除";
		return 0;
	}
	cout<<"请输入要删除学生的名字：\n";
	cin>>name;
	p2=p1=head;
	int j=0;
	if( ( strcmp(name,head->name)==0 ) && (head!=NULL)) {
		head=head->next;
		free(p1);
		j=1;
	} else {
		p1=head->next;
		while(p1!=NULL) {
			if(strcmp(name,p1->name)==0) {
				p2->next=p1->next;
				free(p1);
				j=1;
				break;
			} else {
				p2=p1;
				p1=p2->next;
			}
		}
	}
	if(j==0)
		cout<<"此学生不存在，删除失败!\n";
	else
		cout<<"删除成功!\n";
	return head;
}

void *information::search(Student *head) {
	char name[20];
	p1=new Student;
	cout<<"请输入要查找学生的姓名：\n";
	cin>>name;
	p1=head;
	for(p1=head; p1!=NULL; p1=p1->next) {
		if(strcmp(name,p1->name)==0 ) {
			cout<<"学号:"<<p1->id<<endl;
			cout<<"姓名:"<<p1->name<<endl;
			cout<<"性别:"<<p1->sex<<endl;
			cout<<"专业:"<<p1->major<<endl;
			cout<<"家庭住址:"<<p1->addr<<endl;
			cout<<"出生日期:"<<p1->year<<"年"<<p1->month<<"月"<<p1->day<<"日出生"<<endl;
			cout<<"英语成绩:"<<p1->engli<<endl;
			cout<<"备注:"<<p1->remark<<endl;
		}
	}
	return head;
}

Student *information::modify(Student *head) {

	if(head==NULL) {
		cout<<"没有数据，请新建数据!";
		return 0;
	}
	char name1[12];
	char sex[3];
	char major[20];
	char addr[30];
	char year[5];
	char month[3];
	char day[3];
	int engli;
	char remark[100];
	p1=new Student;
	int j=0;
	p1=head;
	cout<<"请输入你要更改学生的姓名:\n";
	cin>>name;

	if(strcmp( name, head->name)==0) {
		cout<<"显示要修改学生的信息:\n";
		s.displaynode(p1);
		cout<<"请输入要更改学生的信息：\n";
		cout<<"姓名:  \t";
		cin>>name1;
		cout<<"性别:  \t";
		cin>>sex;
		cout<<"专业:  \t";
		cin>>major;
		cout<<"家庭住址:  \t";
		cin>>addr;
		cout<<"出生年:";
		cin>>year;
		cout<<"出生月:";
		cin>>month;
		cout<<"出生日:";
		cin>>day;
		cout<<"英语:";
		cin>>engli;
		cout<<"备注:";
		cin>>remark;
		strcpy(head->name,name1);
		strcpy(head->sex,sex);
		strcpy(head->major,major);
		strcpy(head->addr,addr);
		strcpy(head->year,year);
		strcpy(head->month,month);
		strcpy(head->day,day);
		head->engli=engli;
		strcpy(head->remark,remark);
		j=1;
	} else {
		p1=head->next;
		while(p1!=NULL) {
			if(strcmp(p1->name,name)==0)
			cout<<"显示要修改学生的信息:\n";
			s.displaynode(p1);
			cout<<"请输入要更改学生的信息：\n";
			cout<<"姓名:  \t";
			cin>>name1;
			cout<<"性别:  \t";
			cin>>sex;
			cout<<"专业:  \t";
			cin>>major;
			cout<<"家庭住址:  \t";
			cin>>addr;
			cout<<"出生年:";
			cin>>year;
			cout<<"出生月:";
			cin>>month;
			cout<<"出生日:";
			cin>>day;
			cout<<"英语:";
			cin>>engli;
			cout<<"备注:";
			cin>>remark;
			strcpy(p1->name,name1);
			strcpy(p1->sex,sex);
			strcpy(p1->major,major);
			strcpy(p1->addr,addr);
			strcpy(head->year,year);
			strcpy(head->month,month);
			strcpy(head->day,day);
			p1->engli=engli;
			strcpy(head->remark,remark);
			j=1;
			break;
		}
	}
	if(j==0)
		cout<<"没有找到你要更改的学生，更改失败！\n";
	else
		cout<<"更改成功!\n";
	return head;
}

void information::display(Student *head) {
	p1=head;
	if(p1==NULL)
		cout<<"没有学生信息，请先输入学生信息。"<<endl;
	else {
		while(p1!=NULL) {
			s.displaynode(p1);
			p1=p1->next;
		}
	}
}
void information::displaynode(Student *head) {
	p1=head;
	if(p1==NULL)
		cout<<"这是一个空表！请先输入学生信息。"<<endl;
	else {
		cout<<"学号:"<<p1->id<<endl;
		cout<<"姓名:"<<p1->name<<endl;
		cout<<"性别:"<<p1->sex<<endl;
		cout<<"专业:"<<p1->major<<endl;
		cout<<"家庭住址:"<<p1->addr<<endl;
		cout<<"生日: "<<p1->year<<"年";
		cout<<p1->month<<"月"<<p1->day<<"日"<<endl;
		cout<<"英语成绩:"<<p1->engli<<endl;
		cout<<"备注:"<<p1->remark<<endl;
	}
}


Student *information::read_file() {
	int i=0;
	int id;
	char name2[12];
	char major[20];
	char sex[3];
	char addr[30];
	char year[5];
	char month[3];
	char day[3];
	int engli;
	char remark[100];
	p1=p2=new Student;
	head=NULL;
	ifstream in;
	in.open("E:\\新生管理系统.txt");
	if(!in) {
		cout<<"打开文件失败！"<<endl;
	} else {
		while(!in.eof()) {
			in>>id>>name2>>sex>>major>>addr>>year>>month>>day>>engli>>remark;
			//判断是否到文件的末尾
			if(in.fail()){
				break;
			}
			p1->id=id;
			strcpy(p1->name,name2);
			strcpy(p1->sex,sex);
			strcpy(p1->major,major);
			strcpy(p1->addr,addr);
			strcpy(p1->year,year);
			strcpy(p1->month,month);
			strcpy(p1->day,day);
			p1->engli=engli;
			strcpy(p1->remark,remark);
			i++;
			if(i==1) {
				head=p2=p1;
			} else {
				p2->next=p1;
			}
			p2=p1;
			p1=new Student;
			p1->next=NULL;
		}
		cout<<"成功读取文件！内容如下："<<endl;
	}
	return head;
}

void information::write_file(Student *head) {
	ofstream out;
	out.open("E:\\新生管理系统.txt");
	if(!out) {
		cout<<"打开文件失败！"<<endl;
	}
	p1=NULL;
	p1=head;
	while(p1) {
		out<<p1->id<<" "<<p1->name<<" "<<p1->sex<<" "<<p1->major<<" "<<p1->addr<<" "<<p1->year<<" "<<p1->month<<" "<<p1->day<<" "<<p1->engli<<" "<<p1->remark<<endl;
		p1=p1->next;
	}
	out.close();
	cout<<"写入完毕。";
}

Student *information::sort(Student *head) {
	Student *p,*q,*small;
	int id;
	char name[12];
	char sex[3];
	char major[20];
	char addr[30];
	char year[5];
	char month[3];
	char day[3];
	int engli;
	char remark[100];
	p=head;
	for(; p->next!=NULL; p=p->next) {
		small=p;
		for(q=p->next; q; q=q->next) {
			if(q->engli<small->engli) {
				small=q;
			}
		}
		if(small!= p) {
			id=p->id;
			p->id=small->id;
			small->id=id; 
			engli=p->engli;
			p->engli=small->engli;
			small->engli=engli;
			strcpy(name,p->name);
			strcpy(p->name,small->name);
			strcpy(small->name,name);
			strcpy(major,p->major);
			strcpy(p->major,small->major);
			strcpy(small->major,major);
			strcpy(year,p->year);
			strcpy(p->year,small->year);
			strcpy(small->year,year);
			strcpy(month,p->month);
			strcpy(p->month,small->month);
			strcpy(small->month,month);
			strcpy(day,p->day);
			strcpy(p->day,small->day);
			strcpy(small->day,day);
			strcpy(addr,p->addr);
			strcpy(p->addr,small->addr);
			strcpy(small->addr,addr);
			strcpy(sex,p->sex);
			strcpy(p->sex,small->sex);
			strcpy(small->sex,sex);
			strcpy(remark,p->remark);
			strcpy(p->remark,small->remark);
			strcpy(small->remark,remark);
		}
	}
	return head;
}
char  manage::menu_manager() {
	char ch;
	cout<<endl;
	cout<<endl;
	cout<<"                                                        "<<endl;
	cout<<"                                                        "<<endl;
	cout<<"         *****************新生管理系统****************  "<<endl;
	cout<<"         *               1.新增学生信息              *  "<<endl;
	cout<<"         *               2.插入学生信息              *  "<<endl;
	cout<<"         *               3.删除学生信息              *  "<<endl;
	cout<<"         *               4.查找学生信息              *  "<<endl;
	cout<<"         *               5.修改学生信息              *  "<<endl;
	cout<<"         *               6.按照英语成绩排序          *  "<<endl;
	cout<<"         *               7.统计男/女人数             *  "<<endl;
	cout<<"         *               8.读取学生信息              *  "<<endl;
	cout<<"         *               9.保存信息退出              *  "<<endl;
	cout<<"         *               0.退出                      *  "<<endl;
	cout<<"         *********************************************"<<endl;
	cout<<"请根据需要选择序号:"<<endl;
	cin>>ch;
	return ch;
}

char  manage::menu_user() {
	char ch;
	cout<<endl;
	cout<<endl;
	cout<<"                                                        "<<endl;
	cout<<"                                                        "<<endl;
	cout<<"         *****************新生管理系统****************  "<<endl;
	cout<<"         *               1.查找学生信息              *  "<<endl;
	cout<<"         *               2.按照英语成绩排序          *  "<<endl;
	cout<<"         *               3.统计男/女人数             *  "<<endl;
	cout<<"         *               4.查询所有学生信息          *  "<<endl;
	cout<<"         *               0.退出                      *  "<<endl;
	cout<<"         *********************************************"<<endl;
	cout<<"请根据需要选择序号:"<<endl;
	cin>>ch;
	return ch;
}
int manage::choose_manager() {
	manage m;
	information s;
	Student *head;
	head=NULL;
	int n=0;
	char c;
	while(1)
		switch (m.menu_manager()) {
			case'1':
				head=s.creat();
				system("pause");
				system("cls");
				break;
			case'2':
				head=s.add(head);
				system("pause");
				system("cls");
				break;
			case'3':
				head=s.delet(head);
				system("pause");
				system("cls");
				break;
			case'4':
				s.search(head);
				system("pause");
				system("cls");
				break;
			case'5':
				head=s.modify(head);
				system("pause");
				system("cls");
				break;
			case'6':
				s.sort(head);
				s.display(head);
				system("pause");
				system("cls");
				break;
			case'7':
				s.statistics(head);
				system("pause");
				system("cls");
				break;
			case'8':
				head=s.read_file();
				s.display(head);
				system("pause");
				system("cls");
				break;
			case'9':
				s.write_file(head);
				cout<<"谢谢使用！\n";
				system("pause");
				system("cls");
				return 0;
			case'0':
				cout<<"谢谢使用！\n";
				system("pause");
				system("cls");
				exit(0);
			default:
				cout<<"选择有错，请重新选择\n";
		}
}

int manage::choose_user(Student *p) {
	manage m;
	information s;
	Student *head=p;
	int n=0;
	char c;
	while(1)
		switch (m.menu_user()) {
			case'1':
				s.search(head);
				system("pause");
				system("cls");
				break;
			case'2':
				s.sort(head);
				s.display(head);
				system("pause");
				system("cls");
				break;
			case'3':
				s.statistics(head);
				system("pause");
				system("cls");
				break;
			case'4':
				s.display(head);
				system("pause");
				system("cls");
				break;
			case'0':
				cout<<"谢谢使用！\n";
				system("pause");
				system("cls");
				exit(0);
			default:
				cout<<"选择有错，请重新选择\n";
		}
}

//简易版等待动画 
void Wait()
{
	int i = 0,k = 3;
	Sleep(1000);
	for (i = 0; i < 3;) {
		system("cls");
		cout << k-- << endl;
		i++;
		Sleep(1000);
	}
}

//升级版等待动画 
void Wait1()
{
	Sleep(600);
	system("cls");
	int i,k,count;
    long int a,b;
    i=k=count=0;
    while(!kbhit())
    {
    	if(count==3){
        	break;
		}
        if(k==0)
        {
            printf("Please wait");
        }
        a=b=0;
        for(a=0;a<6000;a++)
   		for(b=0;b<6000;b++);
        printf(".");
        a=b=0;
        for(a=0;a<6000;a++)
   		for(b=0;b<6000;b++);
        k++;
        if(k==6)
        {
            k=0;
            count++;
            system("cls");
        }
    }
}

int login(){
	int i;

	cout<<" *-------------------------------------------------------*"<<endl;
	cout<<" *                欢迎使用新生报到管理系统               *"<<endl;
	cout<<" *                -------------------------              *"<<endl; 
	cout<<" *                  1.管理员                             *"<<endl;
	cout<<" *                  2.普通用户                           *"<<endl;	
	cout<<" *                                                       *"<<endl;
	cout<<" * ------------------------------------------------------* "<<endl;
	cout << "请选择登录身份：";
	cin >> i; 
	return i;
}

int main () {

	system("color 7C");
	int i;
	char ch;
	char str[20];
	char password[9]= {"123456"};
	information f;
	Student *head;

	while(1){
		system("cls");
		int choose = login();
		if(choose == 1){
			while(1) {
			i=0;
			system("cls");
			cout<<"输入密码：";
			ch=getch() ;
			while(ch!=13) {
				if(ch==8&&i>0) {
					i--;
					str[i]='\0';
					system("cls");//清屏 重新输出*
					cout<<"输入密码：";
					for(int j=0; j<i; j++) {
						cout<<"*";
					}
					ch=getch();
				} else {
					printf("*");
					str[i]=ch;
					i++;
					ch=getch();
				}
			}
			str[i]='\0';
				if(!strcmp(str,password)) {
					system("cls");
					cout<<"正确";
					break;
				} else {
					cout<<"\n密码错误!!";
					getch();
					system("cls");
				}
			}
			Wait1();
			system("cls");
		
			system("color 7d");
			manage m;
			m.choose_manager();
		}else if(choose == 2){
			head=f.read_file();
			Wait();
			system("cls");
		
			system("color 7d");
			manage m;
			m.choose_user(head);
		}else{
			cout << "输入错误，请重新输入" << endl;
			system("pause");
		}
	}
	
	
	return 0;
}

10）案例十

#include<iostream>
#include<string.h>
#include<stdlib.h>
#include<fstream>
#include<windows.h>
using namespace std;
class student
{
	public:
		void scanf_student();
		void print_student();
		
		student *next;
		char name[20];        
		char sex[10];        
	    int year;             
		int month;            
		int day;              
    	char major[20];       	
	    char grade;            
		char address[30];     
		long long int number;      
		float chinese_score;  
		float math_score;  
		float English_score; 
		
		void save_file(student *head);
		void look_file(student *head);
};


void student::scanf_student()
{
	cout<<"\n\n";
	cout<<"  请输入学生姓名：";
	cin>>name;
	cout<<"  请输入学生性别：";
	cin>>sex; 
	cout<<"  请输入学生专业：";
	cin>>major;
	cout<<"  请输入学生班级：";
	cin>>grade;
	cout<<"  请输入学生家庭地址：";
	cin>>address;
	cout<<"  请输入学生家庭电话：";
	cin>>number;
	cout<<"  请输入学生入学语文成绩；";
	cin>>chinese_score;
	cout<<"  请输入学生入学数学成绩；";
	cin>>math_score;
	cout<<"  请输入学生入学英语成绩；";
	cin>>English_score;
 } 
 
 
void student::print_student()
{
	cout<<"\n\n";
	cout<<"  学生姓名："<<name<<endl;
	cout<<"\n";
	cout<<"  学生性别："<<sex<<endl;
	cout<<"\n";
	cout<<"  学生专业："<<major<<endl;
	cout<<"\n";
	cout<<"  学生班级："<<grade<<endl;
	cout<<"\n";
	cout<<"  学生家庭地址："<<address<<endl;
	cout<<"\n";
	cout<<"  学生家庭电话："<<number<<endl;
	cout<<"\n";
	cout<<"  学生入学语文成绩："<<chinese_score<<endl; 
	cout<<"\n";
	cout<<"  学生入学数学成绩："<<math_score<<endl;
	cout<<"\n";
	cout<<"  学生入学英语成绩："<<English_score<<endl;
	cout<<"\n\n";
}

void student::save_file(student *head)
{
	student *p;
	p=head->next;
	ofstream ofile("入学新生信息.txt",ios::out);
	while(p!=NULL)
	{
		ofile<<p->name<<'\t'<<p->sex<<'\t'<<p->major<<'\t'<<p->grade<<'\t'<<p->address<<'\t'<<p->number<<'\t'<<p->chinese_score<<'\t'<<p->math_score<<'\t'<<p->English_score<<'\n';
		p=p->next;
	}
	ofile.close();
	cout<<"\n\n保存成功！\n\n"; 
 } 
 
 
void student::look_file(student *head)
{
	student *p1,*p2;
	p1=p2=head;
	ifstream ifile("入学新生信息.txt");
		if(!ifile)
		{
			cout<<"\n打开失败！"<<endl;
			exit(0);
		}
		while(!ifile.eof())
		{
		
		p1=new student;
			if(p1==NULL)
			{
				cout<<"\n创建失败！"<<endl;
				exit(0); 
			}
		ifile>>p1->name>>p1->sex>>p1->major>>p1->grade>>p1->address>>p1->number>>p1->chinese_score>>p1->math_score>>p1->English_score;
		p2->next=p1;
		p2=p1;
	}
	ifile.close();
	p2->next=NULL;
	cout<<"\n\n文件已打开！\n\n";
}


class function:public student
{
	public:
		void creat(student *head);
		void show(student *head);
		void amend(student *head);
		void search(student *head);
		void add(student *head);
	    void delet(student *head);
		void sort(student *head);
		void count(student *head);	
};


void function::creat(student *head)
{
	student *p1,*p2;
	p1=p2=head;
	int z,i;
	cout<<"\n请输入要输入新生的人数：";
	cin>>z;
	system("CLS"); 
	for(i=0;i<z;i++)
	{
		p1=new student;
		if(p1==NULL)
		{
			cout<<"\n输入新生信息失败,请重新输入!\n\n";
			system("CLS");
			function school;
			school.creat(head);
		}
		cout<<"\n***  第"<<i+1<<"个新生  ***";
		p1->scanf_student();
		p2->next=p1;
		p2=p1;
	}
	p2->next=NULL;
	system("CLS");
	cout<<"\n\n新生信息录入完毕！\n\n";
}	


void function::show(student *head)
{
	student *p=head->next;
	int a=1;
	if(p==NULL)
	{
		cout<<"\n\n没有新生信息！\n"<<endl;
	}
	while(p!=NULL)
	{
		cout<<"\n***  第"<<a<<"名新生  ***";  
		p->print_student();
		p=p->next;
		a++;
	}
}
void function::amend(student *head)
{
	student *p;
	p=head->next;
	char name[10],a[10]=" ";
	cout<<"\n请输入要修改学生的姓名：";
	cin>>name;
	while(p!=NULL)
	{
		if(strcmp(p->name,name)==0)
		{
			strcpy(a,name);
			break;
		}
		p=p->next;
	}
	if(strcmp(a," ")==0)
	{
		system("CLS");
		cout<<"\n无该学生信息!"<<endl;
		function school;
		school.amend(head);
		return;
	}
	p->print_student();
	cout<<"修改为："<<endl;
	p->scanf_student();
	system("CLS");
	cout<<"\n\n修改成功！\n\n";
 } 
 
 
void function::search(student *head)
{
	int c;
	char major[10],name[10],a[10]=" ";
	student *p=head->next;
	cout<<"\n*请输入查找学生的姓名：";
	cin>>name;
	system("CLS");
	while(p!=NULL)
	{
		if(strcmp(p->name,name)==0)
		{
			strcpy(a,name);
        	cout<<"\n—— 学生信息 ——  "<<endl;
        	p->print_student();
		}
		p=p->next;
	}
	if(strcmp(a," ")==0)
	{
		system("CLS");
		cout<<"\n无该学生信息!"<<endl;
		function school;
		school.search(head);
	}
}


void function::add(student *head)
{
	int i,n;
	cout<<"\n请输入要输入学生的人数：";
	cin>>n;
	for(i=0;i<n;i++)
	{
		student *p=head,*p1;
	while(p->next!=NULL)
	{
		p=p->next;
	}
	p1=new student;
	cout<<"\n请输入第"<<i+1<<"个新生信息："<<endl;
	p1->scanf_student();
	p1->next=NULL;
	p->next=p1;
	}
		system("CLS");
		cout<<"\n\n添加成功！\n\n";	
}


void function::delet(student *head)
{
	student *p,*q;
	p=head;
	char name[10],a[10]=" ";
	cout<<"\n请输入要删除新生的姓名：";
	cin>>name;
	while(p->next!=NULL)
	{
		if(strcmp(p->next->name,name)==0)
		{
			strcpy(a,name);
         	break;
		}
     	p=p->next;
	}
    if(strcmp(a," ")==0)
	{
    	system("CLS");
    	cout<<"\n没有这个新生的信息，请重新输入！\n";
    	function school;
		school.delet(head);
    	return;
	}	
	q=p->next;
	p->next=q->next;
	system("CLS");
	cout<<"\n\n删除成功！\n\n" ;
}


void function::sort(student *head)
{
	student *p,*q;
	p=head;
	int sum=-1;
	while(p!=NULL) 
	{
		sum++;
		p=p->next;
	}
	int i,j;
	float a;
	char k[50];
	for(i=0;i<sum;i++)
	{
			p=head->next;
        	q=p->next;
		for(j=0;j<sum-1;j++)
		{
			if(p->English_score<p->next->English_score)
			{
			a=p->next->chinese_score;
			p->next->chinese_score=p->chinese_score;
			p->chinese_score=a;
			a=p->next->math_score;
			p->next->math_score=p->math_score;
		    p->math_score=a;
			a=p->next->English_score;
			p->next->English_score=p->English_score;
			p->English_score=a;
			strcpy(k,p->next->name);
			strcpy(p->next->name,p->name);
			strcpy(p->name,k);
			strcpy(k,p->next->sex);
			strcpy(p->next->sex,p->sex);
			strcpy(p->sex,k);
			strcpy(k,p->next->major);
			strcpy(p->next->major,p->major);
			strcpy(p->major,k);
			a=p->next->grade;
			p->next->grade=p->grade;
			p->grade=a;			
			strcpy(k,p->next->address);
			strcpy(p->next->address,p->address);
			strcpy(p->address,k);			
			a=p->next->number;
			p->next->number=p->number;
			p->number=a;
		    }
		    p=p->next;
		 } 
	}
	system("CLS");
		cout<<"\n共"<<sum<<"个新生!"<<endl;
		cout<<"\n按英语入学成绩排序：\n" ;
    	int r=1;
    	q=head->next;
    	while(q!=NULL)
		{
		cout<<"\n***  第"<<r<<"名  ***";  
		q->print_student();
		q=q->next;
		r++;
    	}
} 


void function::count(student *head)
{

	system("CLS");
	student *p; 
	p=head->next;
	cout<<"\n      —— 男生 ——\n"; 
	cout<<"\n**************************\n\n";
	while(p!=NULL)
	{
		if(strcmp(p->sex,"男")==0)
		{
			cout<<"  男生姓名如下：         ";
			cout<<p->name<<endl; 	
			cout<<"\n";
		}	
		    p=p->next;	
	}
	cout<<"**************************"<<endl;
	p=head->next;
	cout<<"\n\n\n      —— 女生 ——\n"; 
	cout<<"\n**************************\n\n";
	while(p!=NULL)
	{
		if(strcmp(p->sex,"女")==0)
		{
			cout<<"  女生姓名如下：         ";
	      	cout<<p->name<<endl; 	
			cout<<"\n";
    	}
		    p=p->next;	
	}
	cout<<"**************************\n\n\n\n"<<endl;
}			


 int main()
{
	int a;
    cout<<"\n\n\t\t";
	system("color 1");
    cout<<"欢";
	Sleep(60);
	system("color 2");
	cout<<"迎";
	Sleep(60);
	system("color 3");
	cout<<"使";
	Sleep(60);
	system("color 4");
	cout<<"用";
	Sleep(60);
    system("color 5");
	cout<<"学";
	Sleep(60);
	system("color 6");
	cout<<"生";
	Sleep(60);
	system("color 7");
	cout<<"成";
	Sleep(60);
	system("color 8");
	cout<<"绩";
	Sleep(60);
	system("color 1");
    cout<<"管";
	Sleep(60);
	system("color 2");
    cout<<"理";
	Sleep(60);
	system("color 3");
	cout<<"系";
	Sleep(60);
	system("color 8");
	cout<<"统\n";
	Sleep(60);
	
	system("color f4");
	student *head;
	head=new student;
	if(head==NULL)
	{
	   cout<<"\n\n  开辟失败！\n"<<endl;
	   exit(0);
	} 
	function school;
	while(1)
	{
	cout<<"\n";
	cout<<"==========================================================\n";
	
	cout<<"=             1 .      录入学生信息                      =\n";
	
	cout<<"=             2 .      添加学生信息                      =\n";
	
	cout<<"=             3 .      显示学生信息                      =\n";
	
	cout<<"=             4 .      搜索学生信息                      =\n";
	
	cout<<"=             5 .      修改学生信息                      =\n";
	
	cout<<"=             6 .      删除学生信息                      =\n";
	
	cout<<"=             7 .      统计学生信息                      =\n";
	
	cout<<"=             8 .      英语成绩排序                      =\n";
	
	cout<<"=             9 .      保存学生信息                      =\n";
	
	cout<<"=             10.      打开学生文件                      =\n";
	
	cout<<"=             0 .      退出信息系统                      =\n";
	 
	cout<<"==========================================================\n";
	
	cout<<"\n*** 请选择：";

		scanf("%d",&a);
		switch(a)
		{
			case 1:system("CLS");school.creat(head);break;
			case 2:system("CLS");school.add(head);break;
			case 3:system("CLS");school.show(head);break;
			case 4:system("CLS");school.search(head);break;
			case 5:system("CLS");school.amend(head);break;
			case 6:system("CLS");school.delet(head);break;
			case 7:system("CLS");school.count(head);break;
			case 8:system("CLS");school.sort(head);break; 
			case 9:system("CLS");school.save_file(head);break;
			case 10:system("CLS");school.look_file(head);break;
			case 0:system("CLS");
			cout<<"\n"; 
		    cout<<"=============================================================\n";
			cout<<"||                                                         ||\n";
			cout<<"||                                                         ||\n";
			cout<<"||                         再见！                          ||\n";
			cout<<"||                                                         ||\n";
		    cout<<"||                                                         ||\n";
			cout<<"=============================================================\n";
			exit(0);
			default:system("CLS");cout<<"输入有误！"<<endl; 
		}
    }
	 return 0;

}

11）案例十一

#include<iostream>
#include<vector>//vector容器的头文件 
#include<fstream>//使用文件的头文件 
#include<iomanip>
#include<windows.h>
using namespace std;
class Human {
	public:
		string hight;
		string weight;
		void Action() {
			cout<<"laugh"<<endl;
			cout<<"cry"<<endl;
			cout<<"learn"<<endl;
		}
};
class Student:public Human { //学生类
	public://数据成员
		string number;//string为字符串类型
		string name;
		string math,english,computer;
		//函数成员
		Student(string nu="0",string na="0",string ma="0",string en="0",string co="0");
		void setstudent(string Nu,string Na,string Ma,string en,string co);
		void setmath(string ma) {
			math=ma;
		}
		void setenglish(string en) {
			english=en;
		}
		void setcomputer(string eo) {
			computer=eo;
		}
		bool searchByNum(string num) { //bool类型函数返回值（返回ture或者false）
			return number==num;
		}
		bool searchByName(string num) {
			return name==num;
		}
		bool search(string num) {
			return number==num;
		}
		void display();
};

Student::Student(string nu,string na,string ma,string en,string co) { //
	number=nu;
	name=na;
	math=ma;
	english=en;
	computer=co;
}

void Student::setstudent(string Nu,string Na,string Ma,string En,string Co) {
	number=Nu;
	name=Na;
	math=Ma;
	english=En;
	computer=Co;
}

void Student::display() { //打印学生信息
	cout<<number<<setw(8)<<name<<setw(6)<<math<<setw(8)
	    <<english<<setw(8)<<computer<<endl;
}

class Order { //操作函数分为一个类
	protected:
		vector<Student>stu;
	public:
		Order() {}
		void Add(Student&s);
		void IdAdd(Student&i);
		void Delete();
		void DeleteAll();
		void Seek();
		void Alter(string ma,string en,string co);
		void Store();
		void Load();
		void Play();
		void Begin();
		void Exit();
		void Sort();
		void test();
	
};

void Order::Add(Student&s) { //添加学生的函数
	cout<<"请输入需要添加的学号：";
	cin>>s.number;
	for(int i=0; i<stu.size(); ++i)
		if(stu[i].search(s.number)) {
			cout<<"该学号学生信息已存在！";
			return;
		}
	cout<<"姓名:";
	cin>>s.name;
	cout<<"数学成绩:";
	cin>>s.math;
	cout<<"英语成绩:";
	cin>>s.english;
	cout<<"计算机成绩:";
	cin>>s.computer;
	stu.push_back(s);
	s.display();
}

void Order::Delete() { //删除学生的函数
	string num;
	cout<<"输入您需要删除的学生的学号";
	cin>>num;
	for(int j=0; j<stu.size(); j++) {
		if(stu[j].search(num))
			stu.erase(stu.begin()+j);
	}
	cout<<num<<"学生信息已删除"<<endl;
	Store();
}

void Order::DeleteAll() { //清除学生数据
	stu.erase(stu.begin(),stu.end());
	cout<<"清除成功"<<endl;
	Store();
}

void Order::Seek() { //查找学生的函数
	string nu;
	cout<<"\t\t\t******************************************************************************"<<endl;
	cout<<"\t\t\t******                        1.通过学号查找学生                         *****"<<endl;
	cout<<"\t\t\t******                        2.通过姓名查找学生                         *****"<<endl;
	cout<<"\t\t\t******************************************************************************"<<endl;
	cout<<"\t\t\t\t请输入选项："<<endl;
	int a;
	cin>>a;
	switch(a) {
		case 1:
			cout<<"请输入您需要查询的学生的学号"<<endl;
			cin>>nu;
			for(int j=0; j<stu.size(); j++) {
				if(stu[j].searchByNum(nu)) {
					cout<<"找到学号为"<<nu<<"的学生,内容是:"<<endl;
					stu[j].display();
				}
			}
			break;
		case 2:
			cout<<"请输入您需要查询的学生的姓名"<<endl;
			cin>>nu;
			for(int j=0; j<stu.size(); j++) {
				if(stu[j].searchByName(nu)) {
					cout<<"找到姓名为"<<nu<<"的学生,内容是:"<<endl;
					stu[j].display();
				}
			}
			break;
			cout<<"没有您要找的学生信息！"<<endl;
	}
}

void Order::Alter(string ma,string en,string co) { //修改学生的函数
	string nu;
	cout<<"请输入您所需要修改成绩的学生学号：";
	cin>>nu;
	for(int j=0; j<stu.size(); j++) {
		if(stu[j].search(nu)) {
			cout<<"请您依次输入需要修改的数学，英语，计算机成绩："<<endl;
			cin>>ma>>en>>co;
			stu[j].math=ma;
			stu[j].english=en;
			stu[j].computer=co;
			cout<<"修改后的学生信息为："<<endl;
			stu[j].display();
		}
	}
}

void Order::Store() { //存储学生信息进入文件中
	ofstream outfile("student.txt");
	if(!outfile.is_open()) {                    //检查文件是否打开成功
		cout<<"没有数据文件！\n\n";
		return;
	}
	for(int i=0; i<stu.size(); i++) {
		outfile<<stu[i].number<<" "<<stu[i].name<<" "<<stu[i].math<<" "<<stu[i].english<<" "<<stu[i].computer<<endl;
	}
	outfile.close();
}

void Order::Sort() { //给学生信息排序
	cout<<"\t\t\t******************************************************************************"<<endl;
	cout<<"\t\t\t******                1.通过英语成绩给学生排序（升序）                   *****"<<endl;
	cout<<"\t\t\t******                  2.通过学号给学生排序（升序）                     *****"<<endl;
	cout<<"\t\t\t******************************************************************************"<<endl;
	cout<<"\t\t\t\t请选择给学生排序的方法："<<endl;
	int a;
	cin>>a;
	Student temp;
	Student remp;
	Order m;
	int i,j,swap,g;
	switch(a) {
		case 1:
			for(i=0; i<stu.size()-1; ++i) {
				swap=0;
				for(j=0; j<stu.size()-i-1; ++j)
					if(stu[j].english>stu[j+1].english) {
						swap=1;
						temp=stu[j];
						stu[j]=stu[j+1];
						stu[j+1]=temp;
					}
				if(!swap)
					break;
			}
			m.Store();
			cout<<"学号"<<setw(6)<<"姓名"<<setw(6)<<"数学"<<setw(6)<<"英语"<<setw(8)<<"计算机"<<endl;
			for(int i=0; i<stu.size(); i++)
				stu[i].display();
			break;
		case 2:
			for(g=0; g<stu.size()-1; ++g) {
				swap=0;
				for(j=0; j<stu.size()-g-1; ++j)
					if(stu[j].number>stu[j+1].number) {
						swap=1;
						temp=stu[j];
						stu[j]=stu[j+1];
						stu[j+1]=temp;
					}
				if(!swap)
					break;
			}
			m.Store();
			cout<<"学号"<<setw(6)<<"姓名"<<setw(6)<<"数学"<<setw(6)<<"英语"<<setw(8)<<"计算机"<<endl;
			for(int g=0; g<stu.size(); g++)
				stu[g].display();
			break;
	}
}

void Order::Load() { //从文件中读取学生信息
	ifstream infile("student.txt");
	if(!infile.is_open()) {//检测文件是否成功打开
		cout<<"没有数据文件！\n\n";
		return;
	}
	string na,nu,ma,en,co;
	while(infile>>nu>>na>>ma>>en>>co) {
		Student temp(nu,na,ma,en,co);
		stu.push_back(temp);
	}
	infile.close();
}

void Order::Play() { //Play函数,打印学生信息的上标（学号，姓名，数学，英语，计算机）
	cout<<"学号"<<setw(6)<<"姓名"<<setw(6)<<"数学"<<setw(6)<<"英语"<<setw(8)<<"计算机"<<endl;
	for(int i=0; i<stu.size(); i++)
		stu[i].display();

}

void Order::Begin() {
	//欢迎界面
	cout<<"\n\n\t\t\t\t\t"<<endl;
	system("color 3");
	cout<<"                  ";
	cout<<"欢         ";
	Sleep(300);
	cout<<"迎         ";
	Sleep(300);
	cout<<"使         ";
	Sleep(300);
	cout<<"用         ";
	cout<<"\n";
	for(int i=1; i<3; i++) {
		system("CLS");
		cout<<"\t\t\t\t\t页面加载中";
		cout<<".";
		Sleep(400);
		cout<<".";
		Sleep(400);
		cout<<".";
		Sleep(400);
	}
}

void Order::Exit() {
	//退出界面
	cout<<"\n\n\t\t\t";
	system("color 3");
	cout<<"感         ";
	Sleep(300);
	cout<<"谢         ";
	Sleep(300);
	cout<<"使         ";
	Sleep(300);
	cout<<"用         ";
	cout<<"\n";
}

void Order::test() {
	cout<<stu.size()<<endl;
}
/* 
class Id
{
	public:
	string id;
	string password;
	bool searchId(id==ID);
};


class IdOrder
{
	public:
		void RecordBegin();
		void Record();
		void IdGreat(Id&m);
		void Idstore();
		void IdLoad();
		vector<Id>ids;
};
void RecordBegin()
{ 
		cout<<"\t\t  ***************************"<<endl;
		cout<<"-->登录"; 
		cout<<"   注册";
		cout<<"\t\t  ***************************"<<endl;
		cout<<"使用'w','s'键进行选择"; 
	for(int i=1;i==1;){
	system("cls");
	char order;
	cin>>order;
	switch(order)
	{
		case 'w':
		cout<<"\t\t  ***************************"<<endl;
		cout<<"-->登录"; 
		cout<<"   注册";
		cout<<"\t\t  ***************************"<<endl;
		break;
		case 's':
		cout<<"\t\t  ***************************"<<endl;
		cout<<"   登录"; 
		cout<<"-->注册";
		cout<<"\t\t  ***************************"<<endl;
		break;
		case ' ':
			i=0;
			break;
		}
	}
	if(order=='w')
	Record();
	else
	IdGreat();
}

viod Record()
{
	cout<<"请输入用户名："<<endl; 
	cin>>id;
	cout<<"请输入密码："<<endl;
	cin>>password;
	
	cin>>password;
	 
}

void IdOrder::IdGreat(Id&m)
{
	cout<<"请输入用户名："<<endl; 
	cin>>id;
	cout<<"请输入密码："<<endl;
	cin>>password;
	cout<<"请再输入一次密码："<<endl;
	cin>>"password1"; 
	for(int i=0; i<ids.size(); ++i)
		if(ids[i].search(m.id)) {
			cout<<"该账号已存在！";
			return;
		}
	if(password==password1)
	cout<<"注册成功"<<endl; 
	ids.push_back(m);
}

void IdOrder::Idstore()//存储账号信息进入文件中
{ 
	ofstream outfile("id.txt");
	if(!outfile.is_open()) {                    //检查文件是否打开成功
		cout<<"没有数据文件！\n\n";
		return;
	}
	for(int i=0; i<ids.size(); i++) {
		outfile<<ids[i].id<<" "<<ids[i].password<<endl;
	}
	outfile.close();
}

void IdOrder::IdLoad()
{
	ifstream infile("id.txt");
	if(!infile.is_open()) {//检测文件是否成功打开
		cout<<"没有数据文件！\n\n";
		return;
	}
	string na,nu,ma,en,co;
	while(infile>>id>>password) {
		Id temp(id,password);
		ids.push_back(temp);
	}
	infile.close();	
}
*/
int main() {
	Student s;//从Student类中声明一个对象
	Order m;//从Order中声明一个对象
	m.Load();
	m.Begin();
	int way;
	string ma,en,co;
	while(1) {
		system("cls");
		system("color 3");
		cout<<"\t\t  *******************************************************************************"<<endl;
		cout<<"\t\t  ******                       学生信息管理系统                             *****"<<endl;
		cout<<"\t\t  ******                                                                    *****"<<endl;
		cout<<"\t\t  ******                        请选择以下指令                              *****"<<endl;
		cout<<"\t\t  ******                        1.添加学生信息                              *****"<<endl;
		cout<<"\t\t  ******                        2.打印学生信息                              *****"<<endl;
		cout<<"\t\t  ******                        3.查找学生信息                              *****"<<endl;
		cout<<"\t\t  ******                        4.删除学生信息                              *****"<<endl;
		cout<<"\t\t  ******                        5.清除所有信息                              *****"<<endl;
		cout<<"\t\t  ******                        6.更改学生信息                              *****"<<endl;
		cout<<"\t\t  ******                        7.学生信息排序                              *****"<<endl;
		cout<<"\t\t  ******                        0.退出学生系统                              *****"<<endl;
		cout<<"\t\t  *******************************************************************************"<<endl;
		cin>>way;
		switch(way) { //根据操作调用函数
			case 1:
				m.Add(s);
				break;//添加
			case 2:
				m.Play();
				break;//打印
			case 3:
				m.Seek();
				break;//查找
			case 4:
				m.Delete();
				break;//删除
			case 5:
				m.DeleteAll();
				break;//清除
			case 6:
				m.Alter(ma,en,co);
				break;//更改
			case 7:
				m.Sort();
				break;
			case 8:
				m.test();
				break;
			case 0:
				m.Store();
				Order m;
				m.Exit();
				return 0;
				break;//退出

		}
		cout<<"\n\t\t按回车键继续！";
		getchar();
		getchar();
	}
	return 0;
}

12）案例十二

#include <iostream>
#include <fstream>
#include <cstring>
#include <windows.h>
#include <time.h>
using namespace std;

class STU            
{	
public:                                      
	   
	string id; 		
	string name;		
	string sex;		
	string major;		
	char adress;
	int score;		
	int year;		
	int month;		
	int day;	
		
	STU *next;
};

class Student: public STU			
{
public:	
	//构造函数	
	Student()        		
	{			
	
	}
	//析构函数		
	~Student()      		
	{					
	
	}		
	
	void Register(Student *head);         //登录 
	void Menu(Student *head);             //菜单
	 
	void insert(Student *head);           //增加 
	void del(Student *head);              //删除
	void Search(Student *head);           //查询 （根据学号或姓名）
	void rewrite(Student *head); 		  //修改
	
	void Sort(Student *head);             //排序  
	void Statistics(Student *head);       //统计 （专业或性别）			
	void Print(Student *head);            //输出
	bool only(Student *head,string id);   //查重 		
	
	void write_File(Student *head);        //文件保存 		
	void read_File(Student *head);         //文件读取 	 
};

void Student::Register(Student *head)
{
	char a[20],b[20],c[20],d[20];
	int num;
	
	cout<<"*****************************"<<endl;
	cout<<"        1.注册              *"<<endl;
	cout<<"        2.登录              *"<<endl;
	cout<<"        0.退出              *"<<endl;
	cout<<"*****************************"<<endl;
	
	cout<<"请输入你的选择：   "<<endl;
	cin>>num;
	if(num==1)
	{
		cout<<"请输入用户名：  "<<endl;
		cin>>a; 
		cout<<"请输入密码：    "<<endl;
		cin>>b;
		cout<<"注册成功！！！"<<endl;
		cout<<"即将离开注册页面  请稍候......  "<<endl;
		Sleep(1000);
		
		while(1)
		{
			system("CLS");
			
			cout<<"**********************"<<endl;
			cout<<"*      1.登录        *"<<endl;
			cout<<"*      0.退出        *"<<endl;
			cout<<"**********************"<<endl;
			
			int x;
			cout<<"请输入你的选择： "<<endl;
			cin>>x;
			
			if(x==1)
			{
				cout<<"请输入用户名：  "<<endl;
				cin>>c;
				if(strcmp(a,c) == 0)
				{
					cout<<"请输入密码：    "<<endl;
					cin>>d;
					if(strcmp(b,d) == 0)
					{
						cout<<"密码正确！！！"<<endl;
						cout<<"即将进入菜单页面  请稍候..."<<endl;
						Sleep(1500);
						
					}else{
						
						cout<<"密码错误！！！"<<endl;
						cout<<"请重新输入密码： "<<endl;
						cin>>d;
						
						if(strcmp(b,d) == 0)
						{
							
							cout<<"密码正确！！！"<<endl;
							cout<<"即将进入菜单页面  请稍候..."<<endl;
							Sleep(1000);
							
						}else{
							cout<<"密码再次错误  即将离开该页面！！！"<<endl;
							exit(0); 
						}
					}
				}else{
					cout<<"用户名输入错误！！"<<endl;
					cout<<"即将离开页面  请稍候..."<<endl;
					Sleep(1500); 
					exit(0); 
				}	
			}if(x==0)
			{
				cout<<"成功退出！！"<<endl; 
				exit(0);
			}
			break;	
		} 	
	}else if(num==2){
		
		cout<<"尚未注册 无法登录！！！"<<endl;
		exit(0);
	}else if(num==0){
		cout<<"成功退出！！！"<<endl;
		exit(0);
	}
	
	return ;
} 

void Student::Menu(Student *head)
{	
	Student STU;
		
	while(1)	
	{  	
		system("CLS");
		system("date/t");	
		system("time/t");
		
		cout<<"                     *********************************************************"<<endl;
    	cout<<"                     *                                                       *"<<endl;
    	cout<<"                     *                                                       *"<<endl;
    	cout<<"                     *             欢迎使用新生基本信息统计系统              *"<<endl;
    	cout<<"                     *                                                       *"<<endl;
    	cout<<"                     *                                                       *"<<endl;
    	cout<<"                     *********************************************************"<<endl;		
			
		cout<<"                     *                                                       **"<<endl;
    	cout<<"                     *                                                       **"<<endl;
        cout<<"                     **********************************************************"<<endl;	
		cout<<"                     **          1.增加学生信息                              **"<<endl;	
		cout<<"                     **          2.删除学生信息                              **"<<endl;
		cout<<"                     **          3.查询学生信息（按学号或姓名）              **"<<endl;
		cout<<"                     **          4.修改学生信息                              **"<<endl;
		cout<<"                     **          5.排序（英语成绩）                          **"<<endl;
		cout<<"                     **          6.统计学生信息（专业/性别）                 **"<<endl;
		cout<<"                     **          7.显示学生信息                              **"<<endl;
		cout<<"                     **          8.学生信息保存                              **"<<endl;			
		cout<<"                     **          9.学生信息读取                              **"<<endl;			
		cout<<"                     **          0.退出该系统                                **"<<endl;
		cout<<"                     **********************************************************"<<endl; 
		cout<<"                     **                                                      **"<<endl;
    	cout<<"                     **                                                      **"<<endl;
        
        cout<<"请输入你的选择："<<endl; 
		
		int choice;	
		cin>>choice;	
		
		switch(choice)	
		{		
			case 1 :
				system("CLS");
				STU.insert(head);
				
				system("pause");
				break;			
			case 2 :
				system("CLS");
				STU.del(head);
				
				system("pause");
				break;		
			case 3 :
				system("CLS");
				STU.Search(head);
				
				system("pause");
				break;		
			case 4 :
				system("CLS");
				STU.rewrite(head);
				
				system("pause");
				break;		
			case 5 :
				system("CLS");
			    STU.Sort(head);
				
				system("pause");
				break;		
			case 6 :								
				system("CLS");
				STU.Statistics(head);		
				
				system("pause");
				break;		
			case 7 :
				system("CLS");
				STU.Print(head);
				
				system("pause");
				break;		
			case 8 :
				system("CLS");
				STU.write_File(head);
				
				system("pause");
				break;		
			case 9 :
				system("CLS");
				STU.read_File(head);
				
				system("pause");
				break;
			case 0 :
				system("CLS");
				cout<<"************************"<<endl;
				cout<<"*                      *"<<endl;
				cout<<"*      谢谢使用！      *"<<endl;
				cout<<"*                      *"<<endl;
				cout<<"************************"<<endl;
				exit(0);
				system("pause");		
			default:
			
				cout<<"输入错误，请重新输入！"<<endl;
				system("pause");	
		}	
	}
}
	
//增加 
void Student::insert(Student *head)      
{	
	STU *p1=head;	
	int num;	
	cout<<"请输入您要添加的学生数量: "<<endl;	
	cin>>num;	
	if(p1->next==NULL)	
	{	
		for(int i=0;i<num;i++)	
		{		
			STU *p2=new Student;		
			cout<<"请输入第"<<i+1<<"位学生的学号:"<<endl;		
			cin>>p1->id;		
			if(Student::only(head,p1->id))		
			{			
				return ;		
			}	
			
			cout<<"请输入第"<<i+1<<"位学生的姓名： "<<endl;		
			cin>>p1->name;		
			cout<<"请输入第"<<i+1<<"位学生的性别： "<<endl;		
			cin>>p1->sex;		
			cout<<"请输入第"<<i+1<<"位学生的专业： "<<endl;		
			cin>>p1->major;		
			cout<<"请输入第"<<i+1<<"位学生的住址： "<<endl;		
			cin>>p1->adress;		
			cout<<"请输入第"<<i+1<<"位学生的英语成绩： "<<endl;		
			cin>>p1->score;		
			cout<<"请输入第"<<i+1<<"位学生的出生日期： "<<endl;		
			cin>>p1->year>>p1->month>>p1->day;	
			cout<<"                "<<endl;
			cout<<"学生信息添加成功！！！"<<endl;
			cout<<"                      "<<endl;
			
			p1->next=p2;		
			p2->next=NULL;		
			p1=p2;	
			
		}			
	}else if(p1->next!=NULL){  
	        //已有学生信息 插在尾部 			
		while(p1->next!=NULL)
		{
			p1=p1->next;
		}
						
		for(int i=0;i<num;i++)		
		{		
			STU *p2=new Student;			
			cout<<"请输入第"<<i+1<<"位学生的学号： "<<endl;
			cin>>p1->id;		
			if(Student::only(head,p1->id))		
			{			
				return ;		
			}		
			cout<<"                             "<<endl;
			cout<<"请输入第"<<i+1<<"位学生的姓名： "<<endl;		
			cin>>p1->name;		
			cout<<"请输入第"<<i+1<<"位学生的性别： "<<endl;		
			cin>>p1->sex;		
			cout<<"请输入第"<<i+1<<"位学生的专业： "<<endl;		
			cin>>p1->major;		
			cout<<"请输入第"<<i+1<<"位学生的住址： "<<endl;		
			cin>>p1->adress;		
			cout<<"请输入第"<<i+1<<"位学生的英语成绩： "<<endl;		
			cin>>p1->score;		
			cout<<"请输入第"<<i+1<<"位学生的出生日期： "<<endl;		
			cin>>p1->year>>p1->month>>p1->day;	
			cout<<"                      "<<endl;
			cout<<"学生信息添加成功！！！"<<endl;
			cout<<"                      "<<endl;
			
			p1->next=p2;		
			p2->next=NULL;		
			p1=p2;		
		}	
	}
}

//删除
void Student::del(Student *head)     
{	
	STU *p1=head;
	STU *p2=new Student;	
	string num;	
	int find=0;
	cout<<"请输入您要删除的学生的学号： "<<endl;	
	cin>>num;	
	if(p1->next==NULL)	
	{		
		cout<<"暂无学生信息存入！"<<endl;	
	
	}else{	
	 
		while(p1->next!=NULL)		
		{		
			if( (p1->next->id) == num)			
			{		
				p2=p1->next;		
				p1->next=p2->next;
			//	p1=p2->next;
			//	delete p2;
				find=1;				
				break; 			
			}
			p2=p1;	  //p1,p2依次向后移一位	
			p1=p1->next;
			break;	
						
		}       
/*		if(p1->next->id==num)
		{
			p2=p1->next;
			p1->next=p2->next;
		}
	//	p2=p2->next;
		
		cout<<"删除成功"<<endl;   */
	}          
		
	if(find)
	{
		cout<<"删除该学生成功！"<<endl; 
	}else{
		cout<<"暂无该学生信息记录"<<endl; 
	}      

} 

//查询 
void Student::Search(Student *head)                   
{	
	STU *p1=head;
	string a="学号",b="姓名"; 
	string gl;
	cout<<"请选择你想要查找的类别（请输入“学号”或“姓名”）：  "<<endl;
	cin>>gl;
	if(gl==a)  //根据学号查找
	{
		STU *p1=head;	
		string num;
		int t=0;	
		cout<<"请输入您要查找的学生学号："<<endl;	
		cin>>num;	
		if(p1->next==NULL)	
		{		
			cout<<"无该学生信息！"<<endl;	
		}else{			
			while(p1->next!=NULL)		
			{	
				if(p1->id==num)
				{
					cout<<"学号:  "<<p1->id<<"  姓名：  "<<p1->name<<"  性别：  "<<p1->sex<<"  专业：  "<<p1->major<<"  住址：  "<<p1->adress<<"  英语成绩：  "<<p1->score<<"  出生日期：  "<<p1->year<<"."<<p1->month<<"."<<p1->day<<endl;			
					
					t=1;
					
					break;
				}else{
					p1=p1->next;
				}						
			}
			
			if(t=0)
			{
				cout<<"该学号不存在！！！"<<endl;
			}else if(t=1){
				cout<<"查询成功！！！"<<endl;
			}	
		
		}
	}else if(gl==b){  //根据姓名查找 
	
		string am;	
		int m=0;
		cout<<"请输入您要查找的学生姓名："<<endl;	
		cin>>am;	
		if(p1->next==NULL)	
		{		
			cout<<"无该学生信息！"<<endl;	
		}else{		
					
			while(p1->next!=NULL)		
			{			
				if(p1->name==am)			
				{		
					cout<<"学号:  "<<p1->id<<"  姓名：  "<<p1->name<<"  性别：  "<<p1->sex<<"  专业：  "<<p1->major<<"  住址：  "<<p1->adress<<"  英语成绩：  "<<p1->score<<"  出生日期：  "<<p1->year<<"."<<p1->month<<"."<<p1->day<<endl;			
			        m=1;
					break;							
				}else{	
						
					p1=p1->next; 	
				}		
			}
				
			if(m=0)
			{
				cout<<"该姓名不存在！！！"<<endl;
			}else if(m=1){
				cout<<"查询成功！"<<endl;
			}
						
		}    
	}	 
}

//修改
void Student::rewrite(Student *head)
{
	STU *p1=head;
	string num;
	int a=0;
	cout<<"请输入你想要修改的学生的学号："<<endl;
	cin>>num;
	if(p1->next==NULL)
	{
		cout<<"暂无学生信息存入！！！"<<endl; 
	}else{
		while(p1->next!=NULL)
		{
			if(p1->id!=num)
			{
				p1=p1->next; 
			}else{    
			
				cout<<"修改姓名为：  "<<endl; 
				cin>>p1->name;
				cout<<"修改性别为：  "<<endl;
				cin>>p1->sex;
				cout<<"修改专业为：  "<<endl;
				cin>>p1->major; 
				cout<<"修改地址为：  "<<endl;
				cin>>p1->adress;
				cout<<"修改成绩为：  "<<endl;
				cin>>p1->score;
				cout<<"修改出生日期为：  "<<endl;
				cin>>p1->year>>p1->month>>p1->day;
			
				cout<<"学号：  "<<p1->id<<"  姓名：  "<<p1->name<<"  性别： "<<p1->sex<<"  专业： "<<p1->major<<"  地址： "<<p1->adress<<"  英语成绩： "<<p1->score<<"  出生日期： "<<p1->year<<p1->month<<p1->day<<endl;			
				a=1;
				break;
			}     
		}
		
		if(a=0)
		{
			cout<<"暂无该学号存入！"<<endl;
		}else if(a=1){
			cout<<"信息修改成功！！！"<<endl; 
		}
	}	
}  

//排序
void Student::Sort(Student *head)
{
	STU *p=head;
	STU *p1=p->next;
	STU temp;
	
	if(p->next==NULL)
	{
		cout<<"无学生信息记录！！！"<<endl; 
	}else{
		
		cout<<"按照英语成绩排序：   "<<endl;
		cout<<"                     "<<endl;
		
		for(  ;p!=NULL;p=p->next)
		{
			for(p1=p->next;p1!=NULL;p1=p1->next)
			{
				if(p->score < p1->score)     //将英语成绩从大到小进行排序 
				{
					temp.id=p1->id;
					p1->id=p->id;
					p->id=temp.id;	
									
					temp.name=p1->name;
					p1->name=p->name;
					p->name=temp.name;	
									
					temp.sex=p1->sex;
					p1->sex=p->sex;
					p->sex=temp.sex;	
									
					temp.major=p1->major;
					p1->major=p->major;
					p->major=temp.major;
										
					temp.adress=p1->adress;
					p1->adress=p->adress;
					p->adress=temp.adress;	
			
					temp.score=p1->score;
					p1->score=p->score;
					p->score=temp.score;
					
					temp.year=p1->year;
					p1->year=p->year;
					p->year=temp.year;	
									
					temp.month=p1->month;
					p1->month=p->month;
					p->month=temp.month;					
					
					temp.day=p1->day;
					p1->day=p->day;
					p->day=temp.day;	
					 
				}
			}
		}
		
		Print(head);    //输出排序后的信息 
	}
	return ;
}

//统计
void Student::Statistics(Student *head)                           
{	
	STU *p1=head;	
	string a="专业",b="性别";     
	string gl;	
	cout<<"请选择您要统计的类别：(请输入“专业”或“性别”)"<<endl;	
	cin>>gl;	
	if(gl==a)      //按专业统计 	
	{		
		string subject;		
		cout<<"请输入想要统计的专业名称：  "<<endl;		
		cin>>subject;		
		int sum=0;		
		if(p1->next==NULL)		
		{			
			cout<<"无学生信息记录！！！"<<endl;		
		}else{			
			while(p1->next!=NULL)			
			{				
				if(p1->major==subject)				
				{					
					sum++;				
				}				
				p1=p1->next;			
			}			
			cout<<"该专业的人数为：  "<<sum<<endl; 		
		}	
	}else if(gl==b)         //按性别统计 	
	{		
		string m;		
		cout<<"请输入要统计的性别：(请输入“男”或“女”)"<<endl;		
		cin>>m;		
		int sum=0;		
		if(p1->next==NULL)		
		{			
			cout<<"暂无学生信息记录！！！"<<endl;		
		}else{			
			while(p1->next!=NULL)			
			{				
				if(p1->sex==m)				
				{					
					sum++;				
				}				
				p1=p1->next;			
			}			
			cout<<m<<"性的人数为：  "<<sum<<endl; 		
		}	
	}
}

//显示学生信息 
void Student::Print(Student *head)      
{	
	STU *p1=head;	
	if(p1->next==NULL)	
	{
			
		cout<<"无学生信息记录！"<<endl;	
		
	}else{		
			
		while(p1->next!=NULL)		
		{			
			cout<<"学号：  "<<p1->id<<"  姓名：  "<<p1->name<<"  性别：  "<<p1->sex<<"  专业：  "<<p1->major<<"  地址：  "<<p1->adress<<"  英语成绩：  "<<p1->score<<"  出生日期：  "<<p1->year<<"."<<p1->month<<"."<<p1->day<<endl;		    
			p1=p1->next;		
		}		
		cout<<"显示成功！！！"<<endl;	
	}
}

//学号查重
bool Student::only(Student *head,string id)     
{	
	STU *p1=head;	
	while(p1->next!=NULL)	
	{		
		if(p1->id==id)		
		{			
			cout<<"学号重复，请勿添加！"<<endl;			
			return true;		
		}		
		p1=p1->next;	
	}	
	return false;
}

void Student::write_File(Student *head)
{	
	STU *p1=head;	
	ofstream outfile("students.txt",ios::out);	
	if(outfile==NULL)	
	{		
		cout<<"打开txt文件失败！"<<endl;	
	}else{		
		p1=head;		
		while(p1->next!=NULL)		
		{			
			outfile<<"  学号：  "<<p1->id<<endl; 
			outfile<<"  姓名：  "<<p1->name<<endl;
			outfile<<"  性别：  "<<p1->sex<<endl;
			outfile<<"  专业：  "<<p1->major<<endl;
			outfile<<"  地址：  "<<p1->adress<<endl;
			outfile<<"  成绩：  "<<p1->score<<endl;
			outfile<<"  出生日期：  "<<p1->year<<"."<<p1->month<<"."<<p1->day<<"."<<endl;			
			
			p1=p1->next;
					
		}		
		outfile.close();		
		cout<<"写入txt文件成功！！！"<<endl;
		cout<<"信息已保存！！！"<<endl;	
	}
}

void Student::read_File(Student *head)
{	
	STU *p1=head;	
	STU *p=new Student;	
	cout<<"正在读取信息  请稍等......"<<endl;
	Sleep(1000);
	system("CLS");
	ifstream infile("students.txt",ios::in);	
	if(!infile)	
	{		
		cout<<"文件里没有数据！！！"<<endl;
		return;	
	}else{		
		int total=0;		
		while(!infile.eof())		
		{	    	
			infile>>p->id;
			infile>>p->name;
			infile>>p->sex;
			infile>>p->major;
			infile>>p->adress;
			infile>>p->score;
			infile>>p->year>>p->month>>p->day;			
			total++;		
				
			cout<<"学号： "<<p->id<<endl;
			cout<<"姓名： "<<p->name<<endl;
			cout<<"性别： "<<p->sex<<endl;
			cout<<"专业： "<<p->major<<endl;
			cout<<"地址： "<<p->adress<<endl;
			cout<<"成绩： "<<p->score<<endl;
			cout<<"出生日期："<<p->year<<"."<<p->month<<"."<<p->day<<endl;
			cout<<"学生数量为：  "<<total<<endl;
			
			cout<<"              "<<endl;
			cout<<"读取成功！！！"<<endl; 
					
		//	delete p;		
			p=NULL;	
			p1=p;
			p1=p1->next;	
			
		}
		infile.close();		
	}
}

int main()
{	
	system("CLS");
	
	system("color 4"); 
	
	Student STU; 
	  
	Student *head=new Student;    
	
	STU.Register(head); 
	
	STU.Menu(head);    
	
	return 0;
}

13）案例十三

#include<iostream>
#include<fstream>
#include<cstring>
#include<stdlib.h>
#include<windows.h>
using namespace std;

//新生信息 
class Student
{
	public:   
	    int num;          //学号 
		char name[20];    //姓名 
		char sex[10];     //性别 
		char major[20];   //专业 
		int date;         //出生日期 
		char address[20]; //家庭地址 
		int score;        //英语入学成绩
		Student *next;
};

class function
{
	public:
		function () {};
		void Enter();                         
		void Menu(Student *head);             //菜单
		void Creat(Student *head);       	  //录入 
    	void Add(Student *head);         	  //增加 
    	void Delete(Student *head);       	  //删除 
    	void Search(Student *head);      	  //查询 
    	void Change(Student *head);      	  //修改 
    	void Print(Student *head);       	  //输出
		void Sort(Student *head);        	  //排序 
    	void Statistics(Student *head);  	  //统计 
    	void In_File(Student *head);     	  //文件读取 
    	void Out_File(Student *head);         //文件保存 
    	~function () {};
};

//登录 
void function::Enter() 
{
	int i=0;
	char account[10]={0};    //账号 
	char password[10]={0};   //密码 
	while(i<3)
	{
	//	system("color B5");
		cout<<"\n";
		cout<<"************欢迎使用新生信息统计系统************\n";
		cout<<"请输入账号: \n";
		cin>>account;
		cout<<"请输入密码: \n";
		cin>>password;
		cout<<"\n";
		if(strcmp(account,"fengmang")==0&&strcmp(password,"666")==0)
		{
			cout<<"登录成功\n";
			break;
		}
		else
		{
			cout<<"密码或用户名错误,请重试\n";
			continue; 
		} 
	} 
	system("pause");  //停顿 
	system("cls");    //清屏 
} 

//录入 
void function::Creat(Student *head) 
{
	Student *p1=head;
	char sex1[3];
    char sex2[3];
    strcpy(sex1, "男");
    strcpy(sex2, "女");
	int n;
	cout<<"请输入学生数量:";
	cin>>n;
	cout<<endl;
	for(int i=0;i<n;i++)
	{
		Student *p2=new Student;
		cout<<"学号:";
		cin>>p2->num;
		cout<<"姓名:";
		cin>>p2->name;
		cout<<"性别:";
		cin>>p2->sex;
		while(strcmp(sex1,p2->sex)!=0 &&strcmp(sex2,p2->sex)!=0 )
        {
            cout<<"请输入格式 :男/女，请重新输入！"<<endl;
            cout<<"性别:";
            cin>>p2->sex;
        }
		cout<<"专业:";
		cin>>p2->major;
		cout<<"出生日期:";
		cin>>p2->date;
		cout<<"家庭住址:";
		cin>>p2->address;
		cout<<"英语入学成绩:";
		cin>>p2->score;
		cout<<endl;
		p1->next=p2;
		p1=p2;
	}	
	p1->next ==NULL;	
}

//输出
void function::Print(Student *head)     
{
	Student *p1=head;
	Student *p2=p1->next;
	while(p2!=NULL)
	{
		cout<<"学号:"<<p2->num<<endl;
		cout<<"姓名:"<<p2->name<<endl;
		cout<<"性别:"<<p2->sex<<endl;
		cout<<"专业:"<<p2->major<<endl;
		cout<<"出生日期:"<<p2->date<<endl;
		cout<<"家庭住址:"<<p2->address<<endl;
		cout<<"英语入学成绩:"<<p2->score<<endl;
		cout<<endl;
	    p2=p2->next;
	}
}

//增加 
void function::Add(Student *head)
{
    Student *p1=head;
    Student *p2=head->next;
    Student *p3;
    char sex1[3];
    char sex2[3];
    strcpy(sex1, "男");
    strcpy(sex2, "女");
    int id;
	bool flag=false;
	cout<<"请输入要插入的位置:";
	cin>>id;
	while(p2!=NULL)
	{
		if(p2->num==id)
   		{
   			p3=new Student;
       		cout<<"请输入要增加的学生的信息:\n";
       		cout<<"学号:";
       		cin>>p3->num;
       		cout<<"姓名:";
       		cin>>p3->name;
       		cout<<"性别:";
       		cin>>p3->sex;
       		while(strcmp(sex1,p3->sex)!=0 &&strcmp(sex2,p3->sex)!=0 )
        	{
            	cout<<"请输入格式 :男/女，请重新输入！"<<endl;
            	cout<<"性别:";
            	cin>>p3->sex;
        	}
   	    	cout<<"专业:";
   	    	cin>>p3->major;
   	    	cout<<"出生日期:";
   	    	cin>>p3->date;
   	    	cout<<"家庭住址:";
   	    	cin>>p3->address;
   	    	cout<<"英语入学成绩:";
   	    	cin>>p3->score;
    		cout<<endl;
    		p3->next=p2->next;
    		p2->next=p3;
    		cout<<"添加成功!\n";
    		flag=true;
    	}
    	p2=p2->next;
	}
	if(flag==false)
	{
		printf("未查询到该学生，增加失败!\n"); 
	}	
}

//删除
void function::Delete(Student *head)
{
	Student *p1=head;
	Student *p2=p1->next; 
	int id;
	bool flag=false;
	cout<<"请输入要删除的学生的学号:";
	cin>>id;
	while(p2!=NULL)
	{
		if(p2->num==id)
		{
			p1->next=p2->next;
			delete p2;
			cout<<"\n删除成功！\n";
			flag=true;
		}
		p2=p2->next;  
	}
	if(flag==false)
	{
		cout<<"无该学生信息，删除失败!\n";
	}
}  

//查询
void function::Search(Student *head)
{
	Student *p1=head;
	Student *p2=head->next;
	int id;
	cout<<"请输入要查找的学生的学号:\n";
	cin>>id;
	bool flag=false;
	while(p2!=NULL)
	{
		if(p2->num ==id)
		{
			cout<<"学号:"<<p2->num<<endl;
			cout<<"姓名:"<<p2->name<<endl;
			cout<<"性别:"<<p2->sex<<endl;
			cout<<"专业:"<<p2->major<<endl;
			cout<<"出生日期:"<<p2->date<<endl;
			cout<<"家庭住址:"<<p2->address<<endl;
			cout<<"英语入学成绩:"<<p2->score<<endl;
			cout<<endl;
			flag=true;
			break;
		}
	    p2=p2->next; 
	}
	if(flag==false)
	{
		cout<<"无该学生的信息!\n";	
	}	
} 

//修改
void function::Change(Student *head)
{
	Student *p1=head;
	Student *p2=head->next;
	char sex1[3];
    char sex2[3];
    strcpy(sex1, "男");
    strcpy(sex2, "女");
	int id;
	bool flag=false;
	cout<<"请输入需要修改的职工的职工号:";
	cin>>id;
	while(p2!=NULL)
	{
		if(p2->num==id)
		{
			cout<<"请输入修改后的学生信息:\n";
			cout<<"学号:";
       		cin>>p2->num;
       		cout<<"姓名:";
       		cin>>p2->name;
       		cout<<"性别:";
       		cin>>p2->sex;
       		while(strcmp(sex1,p2->sex)!=0 &&strcmp(sex2,p2->sex)!=0 )
        	{
            	cout<<"请输入格式 :男/女，请重新输入！"<<endl;
            	cout<<"性别:";
            	cin>>p2->sex;
        	}
   	    	cout<<"专业:";
   	    	cin>>p2->major;
   	    	cout<<"出生日期:";
   	    	cin>>p2->date;
   	    	cout<<"家庭住址:";
   	    	cin>>p2->address;
   	    	cout<<"英语入学成绩:";
   	    	cin>>p2->score;
    		cout<<endl;
			flag=true;
		}
		p2=p2->next ;
	}
	if(flag==false)
	{
		printf("无该学生信息，无法修改!\n");
	}	
}  
 
//排序
void function::Sort(Student *head)
{
	Student *p1=head->next;
	int temp;
	char t[20];
	if(p1==NULL)
	{
		cout<<"无学生信息！\n";
	}
	else
	{
		cout<<"按英语成绩排序：\n";
		while(p1!=NULL)
		{	
			Student *p2=p1->next;
			while(p2!=NULL)
			{
				if(p1->score < p2->score)
				{
					temp=p2->num;p2->num=p1->num;p1->num=temp;
					strcpy(t,p2->name);strcpy(p2->name,p1->name);strcpy(p1->name,t);
					strcpy(t,p2->sex);strcpy(p2->sex,p1->sex);strcpy(p1->sex,t);
					strcpy(t,p2->major);strcpy(p2->major,p1->major);strcpy(p1->major,t);
					temp=p2->date;p2->date=p1->date;p1->date=temp;
					strcpy(t,p2->address);strcpy(p2->address,p1->address);strcpy(p1->address,t); 
					temp=p2->score;p2->score=p1->score;p1->score=temp;
				}
				p2=p2->next;
			}
            p1=p1->next;
		}
	}	
}  
 
//统计
void function::Statistics(Student *head)
{
	Student *p1=head->next;
	string a="专业",b="性别"; 
    string category;
	cout<<"请选择要统计的类别:(请输入“专业”或“性别”)\n";
	cin>>category;
	if(category==a)       //按专业统计 
	{
		string w;  
		cout<<"请输入专业名称：\n";
		cin>>w;
		int sum=0;
		if(p1==NULL)
		{
			cout<<"无学生信息！\n";
		}
		else
		{
			while(p1!=NULL)
			{
				if(p1->major==w)
				{
					sum++;
				}
				p1=p1->next;
			}
			cout<<w<<"专业的人数:"<<sum<<endl; 
		}
	}
	else if(category==b)    //按性别统计 
	{
		string s;
		cout<<"请输入要统计的性别：(请输入“男”或“女”)\n";
		cin>>s;
		int sum=0;
		if(p1==NULL)
		{
			cout<<"无学生信息！\n";
		}
		else
		{
			while(p1!=NULL)
			{
				if(p1->sex==s)
				{
					sum++;
				}
				p1=p1->next;
			}
			cout<<s<<"生的人数:"<<sum<<endl; 
		}
	}
}   
 
//文件保存
void function::Out_File(Student *head)
{
	Student *p1=head;
	Student *p2=head->next;
	ofstream out("D:\\students.txt",ios::out);
	if(out==NULL)
	{
		cout<<"打开文件失败！\n";
		exit(0);
	}
	while(p2!=NULL)
	{
//		out<<"学号"<<"\t"<<"姓名"<<"\t"<<"性别"<<"\t"<<"专业"<<"\t"<<"出生日期"<<"\t"<<"家庭住址"<<"\t"<<"英语入学成绩\n"; 
		out<<p2->num<<"\t"<<p2->name<<"\t"<<p2->sex<<"\t"<<p2->major<<"\t"<<p2->date<<"\t"<<p2->address<<"\t"<<p2->score<<endl;
		p2=p2->next;
	}
	out.close();
	cout<<"\n写入文件成功！\n";
}  
		
//文件读取
void function::In_File(Student *head)
{
	ifstream in;
	Student *p1=head;
	Student *p2=head->next;
	in.open("D:\\students.txt",ios::in);
	if(in==NULL)
	{
		cout<<"打开文件文件失败！\n";
		exit(0);
	}
	while(1)
	{
		p2=new Student;
    	in>>p2->num>>p2->name>>p2->sex>>p2->major>>p2->date>>p2->address>>p2->score;
    	if(in.fail() ) //判断是不是读到了文件结尾
		{
			delete p2;
			p1->next=NULL;
			break;
		} 
    	p1->next=p2;
    	p1=p1->next; 
	}
	cout<<"读取成功!\n";
	function::Print(head);   
	in.close();
}    

//菜单 
void function::Menu(Student *head) 
{
	function STU;
	while(1)
	{
	//	system("color 3F");
		cout<<endl;
    	cout<<endl;
    	cout<<"**************新生信息统计系统***************"<<endl;
    	cout<<"               1.录入学生信息                "<<endl;
    	cout<<"               2.增加学生信息                "<<endl;
    	cout<<"               3.删除学生信息                "<<endl;
    	cout<<"               4.查询学生信息                "<<endl;
    	cout<<"               5.修改学生信息                "<<endl;
    	cout<<"               6.输出学生信息                "<<endl;
    	cout<<"               7.按照英语成绩排序            "<<endl;
    	cout<<"               8.统计学生信息                "<<endl;
    	cout<<"               9.保存学生信息                "<<endl;
    	cout<<"               0.读取学生信息                "<<endl;
    	cout<<"              10.退出系统                    "<<endl; 
    	cout<<"*********************************************"<<endl;
    	cout<<endl;
    	int x;
    	cout<<"请输入所选择的功能序号:"<<endl;
    	cin>>x;  
    	switch(x)
    	{
    		case 1:
    			cout<<"***************录入学生信息***************\n";
            	STU.Creat(head);
            	system("pause");
            	system("cls");
            	break;
        	case 2:
        		cout<<"***************增加学生信息***************\n";
	        	STU.Add(head);
            	system("pause");
            	system("cls");
            	break;
        	case 3:
        		cout<<"***************删除学生信息***************\n";
            	STU.Delete(head);
            	system("pause");
            	system("cls");
            	break;
        	case 4:
        		cout<<"***************查询学生信息***************\n";
            	STU.Search(head);
        		system("pause");
           		system("cls");
           		break;
	       	case 5:
	       		cout<<"***************修改学生信息***************\n";
            	STU.Change(head);
            	system("pause");
            	system("cls");
            	break;
            case 6:
            	cout<<"***************输出学生信息***************\n";
				STU.Print(head);
				system("pause");
            	system("cls");
            	break;
    	   	case 7:
    	   		cout<<"*************按照英语成绩排序*************\n";
            	STU.Sort(head);
            	STU.Print(head);
            	system("pause");
            	system("cls");
            	break;
         	case 8:
         		cout<<"***************统计学生信息***************\n";
            	STU.Statistics(head);
            	system("pause");
            	system("cls");
            	break;
        	case 9:
        		cout<<"***************保存学生信息***************\n";
            	STU.Out_File(head); 
            	system("pause");
            	system("cls");
            	break;
        	case 0:
        		cout<<"***************读取学生信息***************\n"; 
            	STU.In_File(head);
            	system("pause");
            	system("cls");
            	break;
			case 10:
				cout<<"*********感谢使用新生信息管理系统*********\n";
				exit(0);
				break; 
        	default:
            	cout<<"选择错误，请重新选择\n";
            	system("pause");system("cls");function::Menu(head);
            	break;
		}
	}
}

//主函数 
int main ()
{
	function F;
    Student *head=new Student;
    F.Enter();
    F.Menu(head);
    return 0;
}

14）案例十四

#define MAX_NUM 1000

#include <String>

#include <fstream>

#include <iostream>

#include <cstdlib>

#include <ctime>

using namespace std;

bool quit = false;

struct StuNode {

	int num;

	char name[1000];

	int math, eng, yuwen, cyuyan;

	int pj;

	int sum;

	StuNode *nextstu;

};

class people {

		int num;

		char name[1000];

};

class SInfo:private people {                                                                              //设计一个类

	public:

		int math, eng, yuwen, cyuyan;

		int pj;

		int sum;

	private:                                                                              //私有权限

		StuNode *head,*StuListHead,*p1,*p2,*p3;

	public:                                                                               //公共权限

		SInfo();                                                                          //构造函数

		~SInfo();                                                                         //析构函数

		StuNode *CreatSinfo();                                                            //创建学生信息

		StuNode *StuInsert(StuNode *head);                                                //插入学生信息

		void StuDelete(int snum);                                                         //删除学生信息

		StuNode *StuFind(int snum);                                                       //查找学生信息，传入参数学号

		void StuModify(int snum, int smath, int seng, int syuwen, int cyuyan, int spj);   //修改学生信息

		void StuCopy(StuNode *ptemp, StuNode *p);                                         //学生信息拷贝

		void StuSort(char ch);

		void StuClassfy();                                                                //分类合计

		void StuRead();                                                                   //从文件读入学生信息

		void StuSave();                                                                   //保存学生信息到文件

		void StuQuit();                                                                   //退出程序

		void ShowInfo();                                                                 //遍历输出学生信息

};



int Systemdoor()

{

	string username = "0", password = "0";

	string name, temp;

	int number = 3;

	while (1)

	{

		cout<<"                 **********************************                 \n";

		cout<<"                 **                              **                 \n";

		cout<<"                 **  欢迎使用学生信息管理系统！  **                 \n";

		cout<<"                 **                              **                 \n";

		cout<<"                 **********************************                 \n";

		cout<<"                 -----------祝你使用愉快!----------                 \n";

		cout << "                 用 户 名：";

		cin >> name;

		cout << "                 密    码：";

		cin >> temp;

		if (name != username || temp != password)

		{

			number--;

			if (number >0)

			{

				cout << "                 用户名/密码错误!你还有" << number << "次机会" << endl;

				system("pause");

				system("cls");

			}

			else

				cout << "                 用户名/密码错误!" << endl, exit(0);

			system("cls");

		}

		else

		{

			cout << "                 *************密码正确*************" << endl<<endl;

			system("cls");

			return 1;

		}

	}

}

void ShowMenu()

{

	system("cls");

	char ch;

	cout<<"\t\t\t*******************************************************\n";

	cout<<"\t\t\t**                                                   **\n";

	cout<<"\t\t\t**********            欢迎使用！            ***********\n";

	cout<<"\t\t\t**                                                   **\n";

	cout<<"\t\t\t*******************************************************\n";

	cout<<"\t\t\t**                                                   **\n";

	cout<<"\t\t\t**------------------   请选择： ---------------------**\n";

	cout<<"\t\t\t**                                                   **\n";

	cout<<"\t\t\t**---------------0.安全退出学生系统： ---------------**\n";

	cout<<"\t\t\t**                                                   **\n";

	cout<<"\t\t\t**---------------1.文件读入学生信息： ---------------**\n";

	cout<<"\t\t\t**                                                   **\n";

	cout<<"\t\t\t**---------------2.录入新的学生信息： ---------------**\n";

	cout<<"\t\t\t**                                                   **\n";

	cout<<"\t\t\t**---------------3.添加新的学生信息： ---------------**\n";

	cout<<"\t\t\t**                                                   **\n";

	cout<<"\t\t\t**---------------4.删除已有学生信息： ---------------**\n";

	cout<<"\t\t\t**                                                   **\n";

	cout<<"\t\t\t**---------------5.查找已有学生信息： ---------------**\n";

	cout<<"\t\t\t**                                                   **\n";

	cout<<"\t\t\t**---------------6.修改已有学生信息： ---------------**\n";

	cout<<"\t\t\t**                                                   **\n";

	cout<<"\t\t\t**---------------7.已有学生信息排序:  ---------------**\n";

	cout<<"\t\t\t**                                                   **\n";

	cout<<"\t\t\t**---------------8.分类合计学生信息： ---------------**\n";

	cout<<"\t\t\t**                                                   **\n";

	cout<<"\t\t\t**---------------9.输出所有学生信息： ---------------**\n";

	cout<<"\t\t\t**                                                   **\n";

	cout<<"\t\t\t**---------------10.保存现有学生信息：---------------**\n";

	cout<<"\t\t\t**                                                   **\n";

	cout<<"\t\t\t*******************************************************\n";

	time_t now = time(0);

	char* dt = ctime(&now);

	cout << "                        登入系统时本地日期时间：" << dt << endl;

	cout << "\n\t\n\t\t请选择：";
}

SInfo::SInfo()   //构造函数，为对象的成员属性赋值 。

{

	StuListHead = new StuNode;

	StuListHead->nextstu = NULL;

}

SInfo::~SInfo()       //析构函数，在对象销毁系统前系统自动调用，执行一些清理工作。

{

	StuNode *p;

	while (StuListHead)

	{

		p = StuListHead;

		StuListHead = StuListHead->nextstu;

		delete p;

	}

	StuListHead = NULL;

}

StuNode *SInfo::CreatSinfo()     //创建学生信息表

{
	int n;

	StuNode *p, *s;

	p = StuListHead;

	cout << "请输入学生人数：";

	cin >> n;

	for (int i = 1; i <= n; i++)

	{

		s = new StuNode;

		cout<<"请输入学生的信息！\n学号:";

		cin>>s->num;

		cout<<"姓名:";

		cin>>s->name;

		cout<<"数学成绩:";

		cin>>s->math;

		cout<<"英语成绩:";

		cin>>s->eng;

		cout<<"语文成绩:";

		cin>>s->yuwen;

		cout<<"C语言成绩：";

		cin>>s->cyuyan;

		s->pj = (s->math + s->eng + s->yuwen + s->cyuyan)/4;

		s->sum = s->math + s->eng + s->yuwen + s->cyuyan;

		s->nextstu = p->nextstu;

		p->nextstu = s;

		p = p->nextstu;

	}


	if (p == NULL)   //判断学生信息表是否创建成功

	{

		cout << "创建失败请重新创建！" << endl;

		CreatSinfo();

		system("pause");
	}
}

void SInfo::ShowInfo()      //遍历输出

{

	StuNode *p;

	cout << "学号" << '\t' << "姓名" << '\t' << "数学" << '\t' << "英语" << '\t' << "语文" << '\t' << "C语言" << '\t' << "平均分" << '\t' << "总分" << endl;

	for (p = StuListHead->nextstu; p != NULL; p = p->nextstu)

	{

		cout << p->num << '\t' << p->name << '\t' << p->math << '\t' << p->eng << '\t' << p->yuwen << '\t' << p->cyuyan << '\t' << p->pj << '\t' << p->sum << endl;
	}

	system("pause");

}



StuNode *SInfo::StuInsert(StuNode *head)     //插入学生信息（头插法）

{

	StuNode *s,*p;

	int num;

	char name;

	int math;

	int eng;

	int yuwen;

	int cyuyan;

	int pj;

	s = new StuNode;

	cout << "请输入添加学生信息：";

	cout<< "学号：";

	cin >> s->num;

	cout<<"姓名:";

	cin>> s->name;

	cout<<"数学成绩:";

	cin>> s->math;

	cout<<"英语成绩:";

	cin>> s->eng;

	cout<<"语文成绩:";

	cin >> s->yuwen;

	cout<< "C语言成绩：";

	cin>> s->cyuyan;

	s->pj = (s->math + s->eng + s->yuwen + s->cyuyan)/4;

	s->sum = s->math + s->eng + s->yuwen + s->cyuyan;

	p = StuListHead;

	s->nextstu = p->nextstu;

	p->nextstu = s;

}



void SInfo::StuDelete(int snum)

{

	StuNode *p, *ptemp;

	p = StuListHead;

	ptemp = p;

	while (p->nextstu!=NULL && p->num!=snum)   //循环终止条件为p->nextstu不为空 而且没有找到相应学号的学生

	{

		ptemp = p;

		p = p->nextstu;

	}

	if (p->num == snum)

	{

		ptemp->nextstu = p->nextstu;

		delete p;

	}

	else

	{

		cout << "未找到该学生信息！" << endl;

	}

}



StuNode *SInfo::StuFind(int snum)

{

	StuNode *p;

	p = StuListHead->nextstu;

	while (p->nextstu && p->num != snum)   //循环终止条件为p->nextstu不为空 而且没有找到相应学号的学生

	{

		p = p->nextstu;

	}

	if (p->num == snum)

	{

		return p;

	}

	else

	{

		cout << "未找到该学生信息！" << endl;

	}

}



void SInfo::StuModify(int snum, int smath, int seng, int syuwen, int scyuyan, int spj)

{

	StuNode *ItemStu = StuFind(snum);   //直接调用查找函数

	if (ItemStu != NULL)

	{
		ItemStu->num = snum;

		ItemStu->math = smath;

		ItemStu->math = smath;

		ItemStu->eng = seng;

		ItemStu->yuwen = syuwen;

		ItemStu->cyuyan = scyuyan;

		ItemStu->pj = (ItemStu->math + ItemStu->eng + ItemStu->yuwen + ItemStu->cyuyan)/4;

		ItemStu->sum = ItemStu->math + ItemStu->eng + ItemStu->yuwen +  ItemStu->cyuyan;

	}

}



void SInfo::StuCopy(StuNode *ptemp, StuNode *p)  //拷贝学生信息(将p的信息拷贝到ptemp中)

{

	if (p == NULL)

	{

		cout << "拷贝目标为空！" << endl;

	}

	else

	{

		ptemp->num = p->num;

		ptemp->math = p->math;

		ptemp->eng = p->eng;

		ptemp->yuwen = p->yuwen;

		ptemp->cyuyan = p->cyuyan;

		ptemp->pj = p->pj;

		ptemp->sum = p->sum;

	}

}



void SInfo::StuSort(char ch)   //根据 总分排序

{

	if (ch == '>')

	{

		for (StuNode *p = StuListHead->nextstu; p != NULL; p = p->nextstu)

		{

			for (StuNode *q = StuListHead->nextstu; q != NULL; q = q->nextstu)

			{

				if (p->sum > q->sum)

				{

					StuNode *ptemp = new StuNode;

					StuCopy(ptemp, p);

					StuCopy(p, q);

					StuCopy(q, ptemp);

				}

			}

		}

	}

	else if (ch == '<')

	{

		for (StuNode *p = StuListHead->nextstu; p != NULL; p = p->nextstu)

		{

			for (StuNode *q = StuListHead->nextstu; q != NULL; q = q->nextstu)

			{

				if (p->sum < q->sum)

				{


					StuNode *ptemp = new StuNode;

					StuCopy(ptemp, p);

					StuCopy(p, q);

					StuCopy(q, ptemp);

				}

			}

		}

	}

	else if (ch == 'o')

	{

		for (StuNode *p = StuListHead->nextstu; p != NULL; p = p->nextstu)

		{

			for (StuNode *q = StuListHead->nextstu; q != NULL; q = q->nextstu)

			{

				if (p->num < q->num)

				{

					StuNode *ptemp = new StuNode;

					StuCopy(ptemp, p);

					StuCopy(p, q);

					StuCopy(q, ptemp);

				}

			}

		}

	}

	else

	{

		cout << "排序条件出错！" << endl;

	}

}



void SInfo::StuClassfy()  //根据学生总分分类

{

	int grade[5] = {0};

	StuNode *p = StuListHead->nextstu;

	while (p != NULL)

	{

		if (340 < p->sum)

		{

			grade[0]++;

			if (p->cyuyan > 80 && p->eng > 80 && p->math > 80 && p->yuwen >80)

			{

				cout << "优秀学生信息：" <<endl;

				cout << "学号" << '\t' << "姓名" << '\t' << "数学" << '\t' << "英语" << '\t' << "语文" << '\t' << "C语言" << '\t' << "平均分" << '\t' << "总分" << endl;

				cout << p->num << '\t' << p->name << '\t' << p->math << '\t' << p->eng << '\t' << p->yuwen << '\t' << p->cyuyan << '\t' << p->pj << '\t' << p->sum << endl;

			}

		}

		else if (300 < p->sum && p->sum < 340)

		{

			grade[1]++;

		}

		else if (260 < p->sum && p->sum < 300)

		{

			grade[2]++;

		}

		else if (240 < p->sum && p->sum < 260)

		{

			grade[3]++;

		}

		else

		{

			StuNode *p;

			p = StuListHead->nextstu;

			ofstream out("D://补考学生.txt");

			if (!out) {

				cout << "不能打开文件！" << endl;

				return;

			}

			while (p != NULL)

			{
				if(240 > p->sum)

				{

					out << p->num << '\t' << p->name << '\t' << p->math << '\t' << p->eng << '\t' << p->yuwen << '\t' << p->cyuyan << '\t' << p->pj << '\t' << p->sum << '\n';

				}

				p = p->nextstu;

			}

			cout << "学生信息已保存..." << endl;


			grade[4]++;

		}

		p = p->nextstu;

	}

	cout << "A" << '\t' << "B" << '\t' << "C" << '\t' << "D" << '\t' << "E" << endl;

	for (int i = 0; i < 5; i++)

	{

		cout << grade[i] << '\t';

	}

	cout << endl;

}



void SInfo::StuRead()    //从文件读入数据

{

	StuNode *p;

	p = StuListHead;

	ifstream in("D://学生信息.txt");

	if (!in) {

		cout << "没有学生信息，请先录入学生信息!" << endl;

		system("pause");

		return;
	}

	char c;

	cout << "读入学生信息表：" << endl;

	cout << "学号" << '\t' << "姓名" << '\t' << "数学" << '\t' << "英语" << '\t' << "语文" << '\t'  << "C语言" << '\t'  << "平均分" << '\t' << "总分" << endl;

	while(in.get(c))

		while (p != NULL)

		{

			cout << p->num << '\t' << p->name << '\t' << p->math << '\t' << p->eng << '\t' << p->yuwen << '\t' << p->cyuyan <<'\t' << p->pj << '\t' << p->sum << '\n'<<endl;

			p = p->nextstu;

		}

	cout.put(c);

	system("pause");

}



void SInfo::StuSave()   //保存学生信息

{

	StuNode *p;

	p = StuListHead->nextstu;

	ofstream out("D://学生信息.txt");

	if (!out) {

		cout << "不能打开文件！" << endl;

		return;

	}

	while (p != NULL)

	{

		out << p->num << '\t' << p->name << '\t' << p->math << '\t' << p->eng << '\t' << p->yuwen << '\t' << p->cyuyan <<'\t' << p->pj << '\t' << p->sum << '\n';

		p = p->nextstu;

	}

	cout << "学生信息已保存..." << endl;

}



void SInfo::StuQuit()   //学生信息写入文件

{

	char choice;

	cout << "是否保存学生信息：？（Y/N）";

	cin >> choice;

	if (choice == 'y' || choice == 'Y')

	{

		StuSave();

		cout << "学生信息已保存..." << endl;

	}

}



int main()

{

	StuNode *head;

	StuNode *StuListHead;

	system("color F4");

	Systemdoor();

	int x = 100, pnum,pmath,peng,pyuwen,pcyuyan,ppj;

	char pname[1000];

	StuNode *pfind;

	SInfo stu;

	while (x != 0)

	{

		system("cls");      //清屏

		ShowMenu();

		cin >> x;

		switch (x)

		{

			case 0:

				stu.StuQuit();

				break;

			case 1:

				stu.StuRead();

				break;

			case 2:

				stu.CreatSinfo();

				cout << "请核对输入学生信息！" << endl;

				stu.ShowInfo();

				break;

			case 3:

				stu.StuInsert(StuListHead);

				cout << "更新学生信息表..." << endl;

				stu.ShowInfo();

				break;

			case 4:

				cout << "请输入要删除学生学号：";

				cin >> pnum;

				stu.StuDelete(pnum);

				cout << "更新学生信息表..." << endl;

				stu.ShowInfo();

				break;

			case 5:

				cout << "请输入要查找学生学号：";

				cin >> pnum;

				pfind = stu.StuFind(pnum);

				cout << "查找学生学号：" << pfind->num <<" 数学 "<<pfind->math<<" 英语 "<<pfind->eng<<" 语文 "<<pfind->yuwen<<" C语言 "<<pfind->cyuyan <<" 平均分 "<<pfind->pj <<" 总分 " << pfind->sum << endl;

				system("pause");

				break;

			case 6:

				cout << "请输入要修改学生学号：";

				cin >> pnum;

				cout << "请重新输入学生分数：";

				cout << "请输入数学成绩：";

				cin >> pmath ;

				cout << "请输入英语成绩：";

				cin >> peng;

				cout << "请输入语文成绩：";

				cin  >> pyuwen;

				cout << "请输入C语言成绩：";

				cin  >> pcyuyan;

				stu.StuModify(pnum, pmath, peng, pyuwen, pcyuyan, ppj);

				cout << "修改成功！" << endl;

				cout << "更新学生信息表..." << endl;

				stu.ShowInfo();

				break;

			case 7:

				cout << "升序排序（1）降序排序（0）学号排序（10）：";

				cin >> pnum;

				if (pnum == 1)

				{

					stu.StuSort('<');

					stu.ShowInfo();

				}

				else if (pnum == 0)

				{

					stu.StuSort('>');

					stu.ShowInfo();

				}

				else if (pnum == 10)

				{

					stu.StuSort('o');

					stu.ShowInfo();

				}

				else

				{

					cout << "请输入正确选择！" << endl;

				}

				break;

			case 8:

				stu.StuClassfy();

				system("pause");

				break;

			case 9:

				stu.ShowInfo();

				break;

			case 10:

				stu.StuSave();

				system("pause");

				break;

			default:

				cout<<"选择有错，请重新选择\n";


		}

	}
	system("pause");
	return 0;
}

15）案例十五

#include<iostream>
#include<fstream>//该数据类型通常表示文件流
#include<stdio.h>
#include<string> 
#include<iomanip>
#include<cstring>
#include<ctime> //记录时间 
using namespace std;
static int m=0;//总人数 
class Student{
public://封装数据 
    void set_id(int id)                 {this->Id=id;}//调用this指针，把x的值赋给当前对象的X属性。
	void set_name(string name)          {this->Name=name;}	
	void set_sex(string sex)            {this->Sex=sex;}	
	void set_spe(string spe)            {this->Spe=spe;}	
	void set_year(int year)             {this->Year=year;}	
	void set_month(int month)           {this->Month=month;}	
	void set_day(int day)               {this->Day=day;}	
	void set_address(string address)    {this->Address=address;}	
	void set_age(int age)               {this->Age=age;}
	void set_Escore(float Escore)       {this->ESCORE=Escore;}
	int get_id() {return Id;}
	string get_name() {return Name;}
	string get_sex() {return Sex;}
	string get_spe() {return Spe;}
	int get_year() {return Year;}
	int get_month() 
	{return Month;}
	int get_day() {return Day;}
	string get_address() {return Address;}
	int get_age() {return Age;}
	float get_Escore() {return ESCORE;}
    Student *next;
	void show();
	void menu();		
private: //定义属性 
	int Id;//学号 
	string Name;//姓名 
	string Sex;//性别 
	string Spe;//(specialty专业)
	int Year;//年 
	int Month;//月 
	int Day;//日 
	string Address;//住址 
	int Age;//年龄 
	float ESCORE;//英语成绩 
      
};
void Student::show() //单人输出show函数 
{
	cout<<"学号："<<get_id()<<"\t";
	cout<<"姓名："<<get_name()<<"\t";
	cout<<"性别："<<get_sex()<<"\t";
	cout<<"专业："<<get_spe()<<"\t";
	cout<<"出生年月：";
	cout<<get_year()<<"年";
	cout<<get_month()<<"月";
	cout<<get_day()<<"日"<<"\t";
	cout<<"住址："<<get_address()<<"\t";
	cout<<"英语成绩："<<get_Escore()<<"\t";
	cout<<"*********************************************"<<endl;
} 
class message:public Student//函数集合 ，使用公有继承类Student 
{
	public:
	    message(){head=NULL;}
		~message();
		Student* find2(int id);
		bool find1(string name);
		void save();
		void show1();
		void search();
		void add(); 
		void read(); 
		void tongji();
		void rank();
		void shanchu();
		void revision();
		void age_(Student *pt);
	private:
	    Student *p1,*p2,*head;		   
}; 

message::~message()//引用析构函数，释放空间 
{	
	Student *pt;
	while(head)
	{
		pt=head;
		head=head->next;
		delete pt;
	}
}

void message::show1()//遍历数据 
{
	if(head==NULL)
	{
		cout<<"这是一个空列表，请先添加学生信息"<<endl;
		return; 
	}
	cout<<"共"<<m<<"名学生"<<endl;
	p1=head;
	while(p1!=NULL)
	{
		p1->show();
		p1=p1->next;
	} 
} 

void message::add()//添加学生信息 
{
	int n,d,year,month,day;//n为添加新生人数，d为判断男女条件 
	int id;
	string name,spe,sex,address;
	float Escore; 
	p2=head; 
	while(p2)//将数据添加的尾部 
	{
	    if(!p2->next)
		break;
		p2=p2->next;
	}
	cout<<"请输入您要添加人数(人数大于0):";
	cin>>n;
	for(int i=0;i<n;i++)
	{
		cout<<"请输入第"<<i+1<<"个学生的信息"<<endl;
		cout<<"学号:";
		cin>>id;
		p1=new Student();//为新添加的学生信息开辟空间 
		while(find2(id))//判断学号是否重复 
		{
			cout<<"该学号已存在，请重新输入"<<endl;
			cin>>id;
		} 
		p1->set_id(id);
		cout<<"姓名:";
		cin>>name;
		p1->set_name(name);
		cout<<"性别"<<endl<<"1.男  "<<"2.女"<<endl<<"请选择性别(请输入1或2):";
		cin>>d;
		switch(d)
		{
			case 1:p1->set_sex("男");break;
			case 2:p1->set_sex("女");break;
			default:cout<<"稀有物种"<<endl; 
		}
		cout<<"专业"<<endl<<"1.文科  "<<"2.理科"<<endl<<"请选择性别(请输入1或2):";
		cin>>d;
		switch(d)
		{
			case 1:p1->set_spe("文科");break;
			case 2:p1->set_spe("理科");break;
			default:cout<<"未知专业"<<endl; 
		} 
		cout<<"****出生年月****"<<endl<<"年:";
		cin>>year;
		p1->set_year(year);
		cout<<"月(请输入1-12月):";
		cin>>month;
		p1->set_month(month);
		cout<<"日:";
		cin>>day;
		p1->set_day(day);
		cout<<"****************"<<endl;
		cout<<"住址:";
		cin>>address;
		p1->set_address(address);
		cout<<"英语成绩:";
		cin>>Escore;
		p1->set_Escore(Escore);
		p1->next=NULL;//将指针的下一个指向空，结束输入 
		if(head==NULL)
		head=p1;//将指针指向空，防止不必要的麻烦 
		else
		p2->next=p1;
		p2=p1;
		p2->next=NULL;
		m++;//将总人数+1	   
	}
	return; 
}

void message::search()//查询 
{
    int id1;
	string name1;
	int N=0;//N为判断是否换种查询方式条件 
	static int n=0;//n为判断查询条件 
	p1=head;
	if(p1==NULL)
	{
		cout<<"这是一个空列表,请先添加学生信息"<<endl;
		return;
	}
		if(n==0)
		{   
		    cout<<"请选择您要查询的学生信息:"<<"\t"<<"1.学号 2.姓名"<<endl;
		    cin>>n;
		}
		if(n==1)
	    {	
		    cout<<"请输入您要查询的学生学号"<<endl;
	        cin>>id1;
	        if(find2(id1)) 
			    find2(id1)->show();//输出查询到的数据 
		    else
		    {
			    cout<<"没有该生信息,是否选择另一种查询方式?"<<endl<<"1.是  2.否"<<endl;
			    cin>>N;
			    if(N==1)
			    { n=2; search(); }
			    else 
			    { n=0; return; }
		    }
	    }
	    else
	    {
		    cout<<"请输入您要查询的学生姓名"<<endl;
			cin>>name1;
	        if(!find1(name1))
	        {
			    cout<<"没有该生信息,是否选择另一种查询方式?"<<endl<<"1.是  2.否"<<endl;
			    cin>>N;
			    if(N==1)
			    { n=1; search();}
			    else 
			    { n=0; return; }
	        }
	    } n=0;//方便下次使用查询 
}

bool message::find1(string name)//按姓名查找 ，引用bool函数，成立返回true，不成立返回false 
{
	Student *p=head;int i=0;
	while(p)
    {
    	if(p->get_name()==name)
		{
			p->show();i=1;
		}
		p=p->next;
	}
	if(i==0) return false;
	 return true;
}
			
Student* message::find2(int id)//按学号查找 
{
	Student *p=head;
	while(p!=NULL)	
		{
			if(id==p->get_id())
			{
				return p;
			}
			p=p->next;
		}
		return p;//返回查到数据的地址指针 
}

void message::revision()//修改 
{
	int id;
	int n,y,t,year,month,day,age;//y为修改人数，n为修改选项 ,t为继续选择 
	string name,spe,sex,address;
	float Escore;//定义数据 
	if(head==NULL)//查看是否有数据 
	{ 
        cout<<"这是一个空列表，请先添加学生信息"<<endl;
        return; 
	} 
	cout<<"请输入您要修改的人数:"<<endl;
	cin>>y; 
	while(y>m)
	{
		if(y>m)
		cout<<"输入人数大于总人数，请重新输入"<<endl;
		cin.clear();// 清空上一次输入的数据，重新输入，防止进入死循环 
		cin>>y; 
	}
	for(int j=0;j<y;j++)//循环修改次数 
	{
		p1=head;
		p2=head;
		cout<<"请输入您要修改的学生学号"<<endl;
		cin>>id;
		p1=find2(id);//利用查找函数传出数据的指针，将p1赋值 
		if(p1)//如果p1不为空 
		{
			do{
				system("pause");
				system("cls");
				cout<<"****************"<<endl
					<<"*****1.学号*****"<<endl
					<<"*****2.姓名*****"<<endl
					<<"*****3.性别*****"<<endl
					<<"*****4.专业*****"<<endl
					<<"*****5.出生日期*"<<endl
					<<"*****6.英语成绩*"<<endl
					<<"*****7.地址*****"<<endl
					<<"*****8.返回*****"<<endl
					<<"****************"<<endl; 
				cout<<"请选择您要修改的选项:";
				cin>>n;
				switch(n)
				{
				case 1: cout<<"请输入您要修改的学号:"<<endl;
					cin>>id;
					while(find2(id))
					{
						cout<<"学号已存在，请重新输入"<<endl;
						cin>>id;
					}
					p1->set_id(id); 
					cout<<"修改成功"<<endl;
					break;
				case 2:  cout<<"请输入您要修改的姓名:"<<endl;
				    cin>>name;
					p1->set_name(name);
					cout<<"修改成功"<<endl;
					break;
				case 3: cout<<"请输入您要修改的性别:"<<endl<<"1.男  2.女"<<endl<<"请选择你要输入的性别编号";
				    cin>>n;
					if(n==1)
					p1->set_sex("男");
					if(n==2)
					p1->set_sex("女");  
				    cout<<"修改成功"<<endl;
					break;
				case 4: cout<<"请输入您要修改的专业:"<<endl<<"1.理科  2.文科"<<endl<<"请选择你要输入的专业编号";
					cin>>n;
					if(n==1)
					p1->set_spe("文科");
					if(n==2)
					p1->set_spe("理科");  
				    cout<<"修改成功"<<endl;
					break;
				case 5: cout<<"*****出生日期*****"<<endl;
				    cout<<"年:"; 
				    cin>>year;
					p1->set_year(year);
					cout<<"月:";
					cin>>month;
					p1->set_month(month);
					cout<<"日:";
					cin>>day;
					p1->set_day(day);
					cout<<"**************"<<endl;
					break;
				case 6: cout<<"请输入您要修改的英语成绩:";
				    cin>>Escore;
					p1->set_Escore(Escore);
					cout<<"修改成功"<<endl;
					break;
				case 7: cout<<"请输入您要修改的地址:";
				    cin>>address;
					p1->set_address(address);
					cout<<"修改成功"<<endl;
					break;
				case 8: break;
				default:cout<<"选择错误,请重新选择"<<endl;	 	 	 	   		 	 
				}
			}while(n!=8);//当n等于8时，跳出修改 
			cout<<"修改完毕"<<endl; 
		}
		else
		{
			j--;cout<<"没有该生信息"<<endl;//如果未找到，将已经加上的j减一 
		}
	}
	cout<<"是否继续修改？"<<endl;
	cout<<"1.是  2.否"<<endl;
	cin>>t;
	if(t==1) 
	revision();
	else return; 
}

void message::tongji()//信息统计 
{
	int i=0,j=0,k=0,a;//i,j,k为各统计人数 ，a为选择条件 
	p1=head;
	if(head==NULL)
	cout<<"这是一个空列表，请先添加学生信息"<<endl;
	cout<<"请选择统计类型："<<endl;
	cout<<"1.性别"<<"\t"<<"2.专业"<<"\t"<<"3.年龄"<<endl;
	cin>>a;
	switch(a)
	{
	case 1:
		cout<<"男生:"<<endl;
		while(p1!=NULL)
		{	
		    if(p1->get_sex()=="男")	
		    { p1->show();++i;} 
		    p1=p1->next;
	    }	
	    cout<<"男生共"<<i<<"人"<<endl;
		p1=head;
	    cout<<"女生:"<<endl;
     	while(p1!=NULL)
     	{	
       		if(p1->get_sex()=="女")	
	    	{ p1->show();++j;} 
	    	p1=p1->next;
	    }
	    cout<<"女生共"<<j<<"人"<<endl;
	    p1=head;
	    break;
	case 2:
	    cout<<"文科:"<<endl;
		while(p1!=NULL)
	    {	
	    	if(p1->get_spe()=="文科")
     		{ p1->show();++i;}
			p1=p1->next;
    	}cout<<"文科共"<<i<<"人"<<endl;
		p1=head;
	    cout<<"理科:"<<endl;
		while(p1!=NULL)
      	{	
	    	if(p1->get_spe()=="理科")
			{ p1->show();++j;} 
    		p1=p1->next;
    	}cout<<"理科共"<<j<<"人"<<endl;
		p1=head;
        break; 
	case 3:
	    cout<<"年龄为16~18:"<<endl;
		while(p1!=NULL)//如果有数据 
	    {	
	        age_(p1);//将p1当做参数传到计算年龄的函数中，返回计算信息 
   		    if(p1->get_age()>=16&&p1->get_age()<=18)
	    	{ 
			    cout<<"年龄:"<<p1->get_age()<<endl;
			    p1->show();
			    ++i;
			}
	        p1=p1->next;//判断下一个数据符合类型 
    	}cout<<"年龄为16~18共"<<i<<"人"<<endl;
		p1=head;//重新将p1指向开头 
    	cout<<"年龄为19~21:"<<endl;
		while(p1!=NULL)
    	{	
		    age_(p1);
    		if(p1->get_age()>=19&&p1->get_age()<=21)
     		{ 
			    cout<<"年龄:"<<p1->get_age()<<endl;
			    p1->show();
			    ++j;
			} 
    		p1=p1->next;
    	}cout<<"年龄为19~21共"<<j<<"人"<<endl;
		p1=head;
    	cout<<"年龄在16以下，21以上:"<<endl;
		while(p1!=NULL)
    	{	age_(p1);
     		if(p1->get_age()<16||p1->get_age()>21)
     		{ 
			    cout<<"年龄:"<<p1->get_age()<<endl;
			    p1->show();
			    ++k;
			}
     		p1=p1->next;
    	}cout<<"有"<<k<<"年龄在16以下，21以上"<<endl;
		break; 
    default:cout<<"选择错误"<<endl;	
	} 
	cout<<"是否继续统计"<<endl<<"1.是  2.否"<<endl;
	cin>>a;
	if(a==1) tongji();
	else return;
}

void message::age_(Student *pt)//年龄计算 
{
	int age_;
	age_=2019-pt->get_year();//用2019-pt指向的年，得出年龄，并返回给p1 
	pt->set_age(age_); 
}
 
void message::shanchu()//删除
{
	int id1;int n;//n为判断是否按姓名查找学号和是否继续执行条件  
	string name1;//定义查找的名字和学号 
	p2=head;
	if(head==NULL)
	{
		cout<<"这是一个空列表,请先添加学生信息"<<endl;
		return;
	}
	cout<<"请选择您要查找的方式:1.姓名  2.学号"<<endl;
	cin>>n;
	if(n==1)
	{
		cout<<"请输入您要删除的学生姓名"<<endl;
		cin>>name1;
		if(!find1(name1))//如果find1传来的为flase，无此人 
		cout<<"无此人信息"<<endl;//如果未找的，会选择是否继续删除 
		else n=2; //重名现象，再用学号查找 
	}
	if(n==2)
	{
		cout<<"请输入您要删除的学生学号:"<<endl;
		cin>>id1;
		p1=find2(id1);//将找的的数据的地址赋值给p1 
		if(p1)
		{
			ofstream out_("删除文件2.txt",ios::app);
				out_<<"学号:"<<p1->get_id()<<"  "<<"姓名:"<<p1->get_name()<<"   "
		        <<"性别:"<<p1->get_sex()<<"   "<<"专业:"<<p1->get_spe()<<"   ";
		        out_<<"出生日期:"<<p1->get_year()<<"年"<<"  "<<p1->get_month()<<"月"<<"  "<<p1->get_day()<<"日"<<"  ";
		        out_<<"家庭地址:"<<p1->get_address()<<"  "<<"年龄:"<<p1->get_age()<<"  " ;
		        out_<<"英语成绩:"<<p1->get_Escore()<<endl;
			if(p1==head)
			head=p1->next;
			else
			{
				p2->next=p1;
				p2->next=p1->next;
			}
			delete p1;
			cout<<"删除成功"<<endl;
			--m; 
		} 
		else cout<<"没有该生信息"<<endl; 
	}
	if(head==NULL)
	{
		cout<<endl
		<<"*******************************"<<endl
		<<"***信息已全部删除,现文件为空***"<<endl
		<<"*******************************"<<endl;
		return;
	}
    cout<<"是否继续删除?"<<endl<<"1.是  2.否"<<endl;
	cin>>n;
	if(n==1) 
	shanchu();
	else return;
} 

void message::read()//读取 
{
	int year,month,day;
	int id;
	string name,spe,sex,address;
	float Escore;
	head=NULL;
	p2=head;
	ifstream in1("学生信息管理2.txt",ios::in);
	in1>>m;
	if(m==0)
	{ 
	    cout<<"*****此为空文件*****"<<endl;
	    return;
	}
	for(int j=0;j<m;j++)
	{
		p1=new Student();
		in1>>id
		>>
		name>>sex>>spe>>year>>month>>day
		>>Escore>>address;
		p1->set_id(id);
		p1->set_name(name);
		p1->set_sex(sex);
		p1->set_spe(spe);
		p1->set_year(year);
		p1->set_month(month);
		p1->set_day(day);
		p1->set_Escore(Escore);
		p1->set_address(address);
		p1->next=NULL;
		if(head==NULL)head=p1;
		else
		p2->next=p1;
		p2=p1;
		p2->next=NULL;
	}
	in1.close();
	p2->next=NULL;
	cout<<"***************************************************************"<<endl
	<<"***上次保存信息已自动导入***"<<endl;
}

void message::rank()//排序 
{	
    if(head==NULL)//判断是否为空文件 
	{		
		cout<<"这是一个空列表,请先添加学生信息"<<endl;
		return;
	}
	cout<<"按英语成绩排序";		
	Student *pend=head,*p0=new Student();//定义指针pend，并为头结点，开辟新的空间p0	
	p0->next=head;	
	p1=head->next;	
	while(p1)		
	{   Student *pt=p0->next;
		p2=p0;		 
		while(pt!=p1&&pt->get_Escore()>=p1->get_Escore())		
		{	        
			pt=pt->next;	       
			p2=p2->next;	    
		}	  	     
		if(pt==p1)  
			pend=p1;	     
		else	     
		{  
			pend->next=p1->next;        
			p1->next=pt;	        
			p2->next=p1;      
		}	
     p1=pend->next;
	}   		
	head=p0->next;
	delete p0;
	show1();
}

void message::save()  //文件的保存 
{
	ofstream out[2];//定义一个保存文件流数组out【】 
	out[0].open("学生信息管理1.txt",ios::out);
	out[1].open("学生信息管理2.txt",ios::out);
	for(int i=0;i<2;i++)
	{
	p1=head;
	if(i==0)
	out[i]<<"共"<<m<<"名学生"<<endl;
	if(i==1)
	out[i]<<m<<endl;
	while(p1!=NULL)
	{	
		if(i==0)
		{
		out[i]<<"学号:"<<p1->get_id()<<"  "<<"姓名:"<<p1->get_name()<<"   "
		<<"性别:"<<p1->get_sex()<<"   "<<"专业:"<<p1->get_spe()<<"   ";
		out[i]<<"出生日期:"<<p1->get_year()<<"年"<<"  "<<p1->get_month()<<"月"<<"  "<<p1->get_day()<<"日"<<"  ";
		out[i]<<"家庭地址:"<<p1->get_address()<<"  "<<"年龄:"<<p1->get_age()<<"  " ;
		out[i]<<"英语成绩:"<<p1->get_Escore()<<endl;
		p1=p1->next;
		}
		if(i==1)
		{out[i]<<p1->get_id()<<"  "<<p1->get_name()<<"   "<<p1->get_sex()<<"   "<<p1->get_spe()<<"   ";
		out[i]<<p1->get_year()<<"  "<<p1->get_month()<<"  "<<p1->get_day()<<"  ";
		out[i]<<p1->get_Escore()<<endl<<p1->get_address()<<endl;
		p1=p1->next;
		}	
	}
	}
	out[0].close();
	out[1].close();
	cout<<"保存成功"<<endl<<"***信息已保存于学生信息管理1中***"<<endl;
} 
	
void menu()//菜单
{
	system("date/t");//返回当前系统时间
	system("time/t");//显示系统时间
	cout<<"******************************************"<<endl;
	cout<<"1. 新增学生信息"<<endl;                           
    cout<<"2. 删除学生信息"<<endl;                           
    cout<<"3. 导入学生信息"<<endl;
    cout<<"4. 学生信息搜索"<<endl;
    cout<<"5. 学生信息统计"<<endl;
    cout<<"6. 按英语成绩排序"<<endl;
    cout<<"7. 浏览学生信息"<<endl; 
    cout<<"8. 保存学生信息"<<endl;
    cout<<"9. 修改学生信息"<<endl; 
    cout<<"0. 退出"<<endl;
    cout<<"******************************************"<<endl;
 }

void Mima()
{
	cout<<"___________________________________________________________"<<endl;
	cout<<"|*****************欢迎使用学生成绩管理系统****************|"<<endl;
	cout<<"|---------------------------------------------------------|"<<endl;	
	system("color 3"); //调用 color函数可以改变控制台的前景色和背景色 
						// 其中color后面的数字是背景色代号 ，大写字母是前景色代号
	int i=3;
	char num[20];
	char num1[20];		 	 
	char user[20];
	char user1[20];
	char mima[20];
	char mima1[20];
	char mima2[20];
	FILE *fp;			//定义一个指向文件的指针变量 
	char ch;
	do
	{
	    cout<<"1.登录"<<endl;
	    cout<<"2.注册"<<endl; 
	    cout<<"3.修改密码"<<endl;
	    cout<<"4.忘记密码"<<endl;
	    cout<<"0.退出"<<endl;
		    cout<<"请输入你要选择的功能0~3 : "<<endl;
		    cin>>ch;
		    cin.clear();			//清空缓冲区 
		    switch(ch)
			{
				case '1':		//将fopen函数的返回值赋给指针变量fp 
			    	if((fp=fopen("mima.txt","r"))==NULL)  //第一次登录时先创建账号  
			    	{
						fclose(fp);   			//把指向fp的文件关闭，此后fp不在指向该文件 
						cout<<"请先注册账号"<<endl;
						Mima();     
					}
					else				//第二次登陆时直接用密码账号登录即可 
					{
						fp=fopen("mima.txt","r");		//打开文件 
						fscanf(fp,"%s %s",user,mima);	// 从磁盘文件上读入ASCLL字符 
						while(1)
						{
							cout<<"请输入用户名:"<<endl;
							cin>>user1;
							if(strcmp(user,user1)!=0)
							{
								cout<<"用户名错误！！请重新输入！！"<<endl;
							}
							else
							{
								break;
							}
						}
						cout<<"请输入密码:"<<endl;
						while(1)
						{
							cin>>mima1;
							if(strcmp(mima,mima1)!=0)
							{
								cout<<"密码错误！请重新输入密码:"<<endl;
								if(i==1)
								{
									exit(0);	//三次密码输入错误后直接结束该程序 
								}
								i--;
							}
							else
							{
								break;
							}
						}	
					}	
					fclose(fp);		//关闭文件 
					break;
				case '2':
					fp=fopen("mima.txt","w");
			   		cout<<"请创建用户:"<<endl;
			   		cin>>user;
			   		while(1)
			  	 	{
			   			cout<<"请输入密码"<<endl;
			   			cin>>mima; 
			   			cout<<"请从新输入密码"<<endl;
			   			cin>>mima1;
			   			if(strcmp(mima,mima1)!=0)
			   			{
			   				cout<<"密码错误!"<<endl;
						}
						else
						{
							cout<<"请输入你的联系方式:(方便找回账号)"<<endl; 
							cin>>num;
							cout<<"创建成功!!"<<endl;
							break;
						}   
					}
					fprintf(fp,"%s %s %s",user,mima,num);// 将用户名和密码和号码输出到磁盘文件上 
					fclose(fp);//关闭文件 
					break;					
				case '3':
					fp=fopen("mima.txt","r");
					fscanf(fp,"%s %s %s",user,mima,num);
					fclose(fp);
					cout<<"请输入用户名:"<<endl;
					while(1)
					{
						cin>>user1;
						if(strcmp(user,user1)!=0)
						{
							cout<<"用户名错误！请重新输入用户名:"<<endl;
						}
						else
						{
							break;
						}
					}	 
					cout<<"请输入原密码:"<<endl;
					while(1)
					{
						cin>>mima1;
						if(strcmp(mima,mima1)!=0)
						{
							cout<<"密码错误!请重新输入密码:"; 
						}
						else
						{
							break;
						}
					}
					cout<<"请输入新的密码:"<<endl;
					cin>>mima1;
					cout<<"请确认密码:";
					while(1)
					{
						cin>>mima2;
						if(strcmp(mima1,mima2)!=0)
						{
							cout<<"密码错误！请重新输入密码:";
						}
						else
						{
							strcpy(mima,mima1);			//修改密码成功后用新密码覆盖原密码 
							cout<<"修改成功!!"<<endl;
							fp=fopen("mima.txt","w");
							fprintf(fp,"%s %s %s",user,mima,num);	//然后重新输出到磁盘文件上 
							fclose(fp);
							break;
						}	
					}
					break;			
				case '4':
					fp=fopen("mima.txt","r");
					fscanf(fp,"%s %s %s",user,mima,num);
					fclose(fp);
					cout<<"请输入用户名:"<<endl;
					while(1)
					{
						scanf("%s",user1);
						
						if(strcmp(user,user1)!=0)
						{
							cout<<"用户名错误！请重新输入用户名:"<<endl;
						}
						else
						{
							break;
						}
					}
					cout<<"请输入联系方式:"<<endl;
					while(1)
					{
						cin>>num1;
						if(strcmp(num,num1)!=0)
						{
							cout<<"联系方式错误，请重新输入:"; 
						}
						else
						{
							break;
						}
					}
					cout<<"请输入新的密码:"<<endl;
					cin>>mima1;
					cout<<"请确认密码:";
					while(1)
					{
						cin>>mima2;
						if(strcmp(mima1,mima2)!=0)
						{
							cout<<"密码错误！请重新输入密码:";
						}
						else
					{
						strcpy(mima,mima1);			//修改密码成功后用新密码覆盖原密码 
						cout<<"修改成功!!"<<endl;
						fp=fopen("mima.txt","w");
						fprintf(fp,"%s %s %s",user,mima,num);	//然后重新输出到磁盘文件上 
						fclose(fp);
						break;
					}
					}
					break;
				case '0':cout<<endl<<"即将退出程序!"<<endl;
					   	 exit(0);				//结束程序 
				default :system("CLS"); 		//清屏 
						 cout<<"输入错误！请重新输入！"<<endl;
						 Mima();	//当输入的不是指定的三个数时重新跳转本页面 
			}
		}while(ch==1||ch==0);
	system("CLS");		//执行完后实现清屏操作 
}
int main()
{	
    message s;
	int i;
	Mima();
	do{	
	    menu();
		cin>>i;
		system("cls");
		switch(i)
		{
			case 1:system("cls");s.add();break;
			case 2:system("cls");s.shanchu();break;
			case 3:system("cls");s.read();break;
			case 4:system("cls");s.search();break;
			case 5:system("cls");s.tongji();break; 
			case 6:system("cls");s.rank();break;
			case 7:system("cls");s.show1();break;	
			case 8:system("cls");s.save();break;
			case 9:system("cls");s.revision();break;
			case 0:cout<<"感谢你的使用！"<<endl;system("pause");return 0;
			default:cout<<"选择错误，请重新输入"<<endl;system("cls");				
		}
	}while(i!=0);
	system("pause");
	return 0;
}