图书管理系统

#include <iostream>
#include <vector>
using namespace std;
#define list 1
struct a{
    string name;
    int id;
    int age;
    string Class;
}index;
void MAIN(){
    cout<<"欢迎使用学生管理系统"<<endl
        <<"1.请输入您的书籍名称"<<endl
        <<"2.查找书籍信息"<<endl
        <<"3.修改书籍信息"<<endl
        <<"4.删除书籍信息"<<endl
        <<"5.退出管理系统"<<endl;
}
void FMAIN(){
    cout<<"请选择您要查找的方式:"<<endl
        <<"1.根据书号查找"<<endl
        <<"2.根据书名查找"<<endl
        <<"3.返回主界面"<<endl;
}
void FFMAIN(string n){
    cout<<"请选择您要"<<n<<"的方式:"<<endl
        <<"1.根据书号"<<n<<endl
        <<"2.返回"<<n<<endl;
}
vector<a> no1(vector<a> x,int number);
vector<a> no2(vector<a> x,int number);
vector<a> no3(vector<a> x,int number);
vector<a> no4(vector<a> x,int number);
int main(){
    vector<a>x;
    int n,number = 0;
    while(1){
        MAIN();
        cin>>n;
        if(n>5){
            system("cls");
            continue;
        }else if(n==5){
            system("pause");
            break;
        }
        switch(n){
            case 1:
                x = no1(x,number);
                number++;
                break;
            case 2:
                x = no2(x,number);
                break;
            case 3:
                x = no3(x,number);
                break;
            case 4:
                x = no4(x,number);
                break;
            case 5:
                system("pause");
                return 0;
        }
        system("pause");
        system("cls");
    }
    return 0;
}
vector<a> no1(vector<a> x,int number){
    cout<<"请输入您的书籍名称:"<<endl;
    cin>>index.name;
    cout<<"书籍编号是:"<<index.id<<endl;
    x.push_back(index);
    return x;
}
vector<a> no2(vector<a> x,int number){
    int n;
    while(1){
        system("cls");
        FMAIN();
        cin>>n;
        if(n==3){
            break;
        }
        int _id,_age;
        string _name,_class;
        bool have = false;
        switch(n){
            case 1:{
                cout<<"请输入您的要存入的书籍:";
                cin>>_id;
                for(int i = 0;i<x.size();i++){
                    if(_id==x[i].id){
                        cout<<"书籍:"<<x[i].name<<endl;
                        have = true;
                    }
                }
                if(!have){
                    cout<<"查找失败"<<endl;
                }
                break;
            }
            case 2:{
                cout<<"请输入您的要存入的书籍:";
                cin>>_name;
                for(int i = 0;i<x.size();i++){
                    if(_name==x[i].name || x[i].name.find(_name)!=string::npos){
                        cout<<"姓名:"<<x[i].name<<endl;
                        cout<<"书籍的编号:"<<x[i].id<<endl;
                        cout<<endl;
                        have = true;
                    }
                }
                if(!have){
                    cout<<"查找失败"<<endl;
                }
                break;
            }
            case 3:{
                cout<<"请输入你的书籍编号:";
                cin>>_age;
                for(int i = 0;i<x.size();i++){
                    if(_age==x[i].age){
                        cout<<"书名:"<<x[i].name<<endl;
                        cout<<"书籍编号:"<<x[i].id<<endl;
                        cout<<endl;
                        have = true;
                    }    
                }
                if(!have){
                    cout<<"查找失败"<<endl;
                }
                break;
            }
        }
        system("pause");
    }
    return x;
}
vector<a> no3(vector<a> x,int number){
    int n;
    while(1){
        system("cls");
        FFMAIN("修改");
        cin>>n;
        if(n==2){
            break;
        }
        int _id,_age,_class;
        string _name;
        bool have = false;
        switch(n){
            case 1:
                cout<<"请输入你的书籍编号:";
                cin>>_id;
                for(int i = 0;i<number;i++){
                    if(list+i==_id){
                        system("cls"); 
                        cout<<"请选择你要修改的信息"<<endl
                            <<"*****1.修改书名*****"<<endl
                            <<"*****4.返回*********"<<endl;
                        int _n;
                        cin>>_n;
                        switch(n){
                            case 1:{
                                cout<<"请输入你要修改的书名:";
                                cin>>_name;
                                x[i].name = _name; 
                                break;
                            }
                            case 4:{
                                break;
                            }
                        }
                        have = true;   
                    }    
                }
                if(!have){
                    cout<<"修改失败"<<endl;
                    break;
                }
                cout<<"修改成功"<<endl;
                break;
            }
        system("pause");
    }
    return x;
}
vector<a> no4(vector<a> x,int number){
    int _id;
    cout<<"请输入你的书号:";
    cin>>_id;
    bool have = false;
    for(int i = 0;i<number;i++){
        if(_id==x[i].id){
            x.erase(x.begin()+i);
            //x[i].id = -1;
            have = true;
        }
    }
    if(!have){
        cout<<"删除失败"<<endl;
        return x;
    }
    cout<<"删除成功"<<endl;
    return x;
}