图书管理（单链表C++）

#include<iostream>
#include<string>
#include<iomanip>
#include<fstream>
using namespace std;

#define OK 1
#define ERROR -1
#define OVERFLOW -2
typedef int Status;          //函数返回值类型，函数状态代码
#define MAXSIZE 100          //线性表可能达到的最大长度
int length=0;
string head_1,head_2,head_3;
typedef struct{
    string id;               //图书编号
    string name;             //图书名称
    double price;            //图书价格 
}Book;
typedef struct LNode{
    Book data;               //数据域
    struct LNode *next;      //指针域 
}LNode,*LinkList;
Status InitList_L(LinkList &L){
    L=new LNode;        //开辟以 LNode 大小的内存空间
    L->next=NULL;
    return OK; 
}
Status CreateList_L(LinkList &L){
    LinkList p,r;
    r=L;
    //string head_1,head_2,head_3;
    fstream file;
    file.open("d:\book.txt");
    if(!file){
        cout<<"没有找到该文件，文件打开失败！"<<endl;
        exit(ERROR); 
    }
    file>>head_1>>head_2>>head_3;
    while(!file.eof()){
        p=new LNode;
        file>>p->data.id>>p->data.name>>p->data.price;
        p->next=NULL;
        r->next=p;
        r=p;
        length++;
    }
    file.close();
    return OK;
}
Status GetElem(LinkList &L,int i){
    LinkList p;
    Book data;
    int j;
    p=L->next;
    j=1;
    while(p&&j<i){
        p=p->next;
        j++;
    }
    if(!p||j>i)
        return ERROR;
    cout<<p->data.id<<"		"<<p->data.name<<"		"<<p->data.price<<endl;
    return OK;
}
Status ListInsert_L(LinkList &L,int i){
    int j;
    LinkList p,s;
    p=L;               //申明一个节点p，指向头节点 
    j=1;
    while(p&&j<i){        //寻找第i个节点
        p=p->next;
        j++;
    }
    if(!p||j>i)          //第 i 个元素不存在
        return ERROR;
    s=new LNode;         //在内存中生成新的节点 
    cin>>s->data.id>>s->data.name>>s->data.price; 
    s->next=p->next;     //将p的后继赋值给s的后继 
    p->next=s;           //将s的后继赋值给p
    return OK; 
}
Status ListDelete_L(LinkList &L,int i){//删除单链表的第 i 个数据元素，表长减一 
    int j;
    LinkList p,r;
    p=L;                 //申明一个节点p，指向第一个节点
    j=1;
    while(p&&j<i){        //寻找将要删除的第 i 个数据 
        p=p->next;
        j++;     
   }
   if(!p||j>i)            //链表中第 i 个数据不存在
        return ERROR;
    r=p->next;               
    p->next=r->next;       //将r的后继赋值给p的后继
    return OK;
} 
int main()
{
    int choose,i; 
    LinkList L,p;                   //定义头结点 
    cout<<"1.建立"<<endl;
    cout<<"2.输入"<<endl;
    cout<<"3.查找"<<endl;
    cout<<"4.插入"<<endl;
    cout<<"5.删除"<<endl;
    cout<<"6.输出"<<endl;
    cout<<"0.退出"<<endl<<endl;
    choose=-1;
    while(choose!=0){
        cout<<"请选择:"<<endl;
        cin>>choose;
        switch(choose){
            case 0:                          //退出 
                cout<<"您已经成功退出系统，欢迎您的到来！"<<endl;
                break; 
            case 1:                         //建立 
                if(InitList_L(L))
                    cout<<"线性链式表已成功建立！"<<endl;
                else
                    cout<<"线性链式表建立失败！"<<endl;
                break;
            case 2:                        //输入 
                if(CreateList_L(L))
                    cout<<"图书信息内容已经成功输入！"<<endl;
                else
                    cout<<"图书信息内容输入失败"<<endl;
                break;
            case 3:                       //查找
                int i;
                cout<<"请您输入将要查找的第几本书"<<endl;
                cin>>i;
                cout<<"您要查找的第"<<i<<"本书的信息如下:"<<endl<<endl;
                GetElem(L,i);
                cout<<"----------------------------------------------------------------------"<<endl;
                break;
            case 4:                   //插入                      
                cout<<"请您输入在第几行插入新的图书:"<<endl;
                cin>>i;
                cout<<"请您为将要插入新的图书依次输入 图书编号、图书名称、图书价格:"<<endl;
                ListInsert_L(L,i);
                cout<<"您插入新的图书信息，如下所示:"<<endl<<endl;
                cout<<left<<head_1<<left<<"				"<<head_2<<left<<"			"<<head_3<<endl;
                p=L->next;
                while(p){
                    cout<<left<<setw(15)<<p->data.id<<"		"<<left<<setw(35)<<p->data.name<<p->data.price<<endl;
                    p=p->next;
                }
                cout<<"----------------------------------------------------------------------"<<endl;
            break;
            case 5:                  //删除
                cout<<"请您输入将要删除的第几个元素:"<<endl;
                cin>>i;
                ListDelete_L(L,i);
                cout<<"您已经成功删除第"<<i<<"个数据"<<endl;
                cout<<"新的图书信息如下所示:"<<endl<<endl;
                cout<<left<<head_1<<left<<"				"<<head_2<<left<<"			"<<head_3<<endl;
                p=L->next;
                while(p){
                    cout<<left<<setw(15)<<p->data.id<<"		"<<left<<setw(35)<<p->data.name<<p->data.price<<endl;
                    p=p->next;
                }
                cout<<"----------------------------------------------------------------------"<<endl;
            break;   
            case 6:                       //输出
                LinkList p; 
                cout<<"图书信息如下:"<<endl<<endl;
                cout<<left<<head_1<<left<<"				"<<head_2<<left<<"			"<<head_3<<endl;
                p=L->next;
                while(p){
                    cout<<left<<setw(15)<<p->data.id<<"		"<<left<<setw(35)<<p->data.name<<p->data.price<<endl;
                    p=p->next;
                }
                cout<<"----------------------------------------------------------------------"<<endl;
            break; 
        }
 }
    return 0; 
}