#include<iostream>
#include<string>
#include<stdlib.h>
using namespace std;
class student
{
public:
    int no;
    string sex;
    string name;
    student *next;
};
class stuqueue
{
public:
    student *front,*rear;
    void inistuqueue(stuqueue &s){
        student *ss;
        ss=new student;
        
        ss->next=NULL;
        s.front=ss;
        s.rear=ss;
    }
    void input(stuqueue &s){
        student *ss;
        int no;string sex;string name;
        ss=new student;
        cout<<"输入学生学号:";cin>>no;
        check(s, no);
        cout<<"输入性别:";cin>>sex;
        cout<<"输入姓名:";cin>>name;
        ss->no=no;
        ss->sex=sex;
        ss->name=name;
        s.rear->next=ss;
        s.rear=ss;
        s.rear->next=NULL;
    }
    void print(stuqueue &s){
        student *p;
        p=s.front->next;
        cout<<" 学生学号      性别      姓名"<<endl;
        while(p!=NULL)
        {cout<<"  "<<p->no<<"       "<<p->sex<<"      "<<p->name<<endl;
         p=p->next;
        }
    }
    student *locate(stuqueue s,int no){
        student *p;
        p=s.front->next;
        while((p!=NULL)&&(p->no!=no))
           p=p->next;
        return p;
    }
    void check(stuqueue s,int no)
    {     student *p;
         p=locate(s,no);
          if(p!=NULL)
        {cout<<"学号重复,请重新输入学生学号:";cin>>no;
         check(s, no);}
    }


    void search(stuqueue s){
         int no;
         cout<<"要查询的学号：";
         cin>>no;
         student *p;
         p=locate(s,no);
          if(p==NULL)
        {cout<<"查无此人"<<endl;}
        else
        {cout<<"学生学号，性别， 姓名"<<endl;
         cout<<"  "<<p->no<<"       "<<p->sex<<"     "<<p->name<<endl;
        }
    }
         
    void gengxin(stuqueue &s){
         int no;
         string sex,name;
         cout<<"输入要更新同学的学号";
         cin>>no;
         student *p;
         p=locate(s,no);
         if(p==NULL){
             cout<<"学号错误，请重新输入";
             cin>>no;
             gengxin( s);}
         else
             cout<<"输入性别:";cin>>sex;
             cout<<"输入姓名:";cin>>name;
             p->sex=sex;
             p->name=name;

    }
    void del(stuqueue &s){
        int no;
        student *p,*q;
        cout<<"输入要删除的学号：";
        cin>>no;
        q=s.front;
        p=s.front->next;
        while((p!=NULL)&&(p->no!=no))
        {q=p;p=p->next;}
        if(p==NULL)cout<<"要删除的人不存在"<<endl;
        else
        {
          q->next=p->next;
          delete p;
        }
    }
};

void menu(stuqueue stu){
    int n;
    cout<<"功能选项（1-6）";
    cin>>n;
    while(n)
    {
        switch(n){
        case 1: stu.input(stu);//输入/添加
                     break;
        case 2: stu.gengxin(stu);//更新
                     break;
        case 3:  stu.search(stu);//查询
                     break;
        case 4:    stu.del(stu);//删除
                     break;
        case 5:   stu.print(stu);//输出
                     break;
        case 6:   exit(0);
                     break;
        }
        cout<<"功能选项（1-6）";
        cin>>n;
    }
}
void main(){
    cout<<"            学生信息管理系统            "<<endl;
    cout<<"-------------------------------------------"<<endl;
    cout<<"1 -输入/添加学生信息    2 - 更新学生信息"<<endl;
    cout<<"3 -查询学生信息         4 - 删除学生信息"<<endl;
    cout<<"5 -输出学生信息         6 - 退出学生管理"<<endl;
    cout<<"-------------------------------------------"<<endl;
    stuqueue stu;
    stu.inistuqueue(stu);
    menu( stu);
}