圖書管理（單鏈表C++）

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

#define OK 1
#define ERROR -1
#define OVERFLOW -2
typedef int Status;          //函數返回值類型，函數狀態代碼
#define MAXSIZE 100          //線性表可能達到的最大長度
int length=0;
string head_1,head_2,head_3;
typedef struct{
    string id;               //圖書編號
    string name;             //圖書名稱
    double price;            //圖書價格 
}Book;
typedef struct LNode{
    Book data;               //數據域
    struct LNode *next;      //指針域 
}LNode,*LinkList;
Status InitList_L(LinkList &L){
    L=new LNode;        //開辟以 LNode 大小的內存空間
    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<<"沒有找到該文件，文件打開失敗！"<<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<<"\t\t"<<p->data.name<<"\t\t"<<p->data.price<<endl;
    return OK;
}
Status ListInsert_L(LinkList &L,int i){
    int j;
    LinkList p,s;
    p=L;               //申明一個節點p，指向頭節點 
    j=1;
    while(p&&j<i){        //尋找第i個節點
        p=p->next;
        j++;
    }
    if(!p||j>i)          //第 i 個元素不存在
        return ERROR;
    s=new LNode;         //在內存中生成新的節點 
    cin>>s->data.id>>s->data.name>>s->data.price; 
    s->next=p->next;     //將p的后繼賦值給s的后繼 
    p->next=s;           //將s的后繼賦值給p
    return OK; 
}
Status ListDelete_L(LinkList &L,int i){//刪除單鏈表的第 i 個數據元素，表長減一 
    int j;
    LinkList p,r;
    p=L;                 //申明一個節點p，指向第一個節點
    j=1;
    while(p&&j<i){        //尋找將要刪除的第 i 個數據 
        p=p->next;
        j++;     
   }
   if(!p||j>i)            //鏈表中第 i 個數據不存在
        return ERROR;
    r=p->next;               
    p->next=r->next;       //將r的后繼賦值給p的后繼
    return OK;
} 
int main()
{
    int choose,i; 
    LinkList L,p;                   //定義頭結點 
    cout<<"1.建立"<<endl;
    cout<<"2.輸入"<<endl;
    cout<<"3.查找"<<endl;
    cout<<"4.插入"<<endl;
    cout<<"5.刪除"<<endl;
    cout<<"6.輸出"<<endl;
    cout<<"0.退出"<<endl<<endl;
    choose=-1;
    while(choose!=0){
        cout<<"請選擇:"<<endl;
        cin>>choose;
        switch(choose){
            case 0:                          //退出 
                cout<<"您已經成功退出系統，歡迎您的到來！"<<endl;
                break; 
            case 1:                         //建立 
                if(InitList_L(L))
                    cout<<"線性鏈式表已成功建立！"<<endl;
                else
                    cout<<"線性鏈式表建立失敗！"<<endl;
                break;
            case 2:                        //輸入 
                if(CreateList_L(L))
                    cout<<"圖書信息內容已經成功輸入！"<<endl;
                else
                    cout<<"圖書信息內容輸入失敗"<<endl;
                break;
            case 3:                       //查找
                int i;
                cout<<"請您輸入將要查找的第幾本書"<<endl;
                cin>>i;
                cout<<"您要查找的第"<<i<<"本書的信息如下:"<<endl<<endl;
                GetElem(L,i);
                cout<<"----------------------------------------------------------------------"<<endl;
                break;
            case 4:                   //插入                      
                cout<<"請您輸入在第幾行插入新的圖書:"<<endl;
                cin>>i;
                cout<<"請您為將要插入新的圖書依次輸入 圖書編號、圖書名稱、圖書價格:"<<endl;
                ListInsert_L(L,i);
                cout<<"您插入新的圖書信息，如下所示:"<<endl<<endl;
                cout<<left<<head_1<<left<<"\t\t\t\t"<<head_2<<left<<"\t\t\t"<<head_3<<endl;
                p=L->next;
                while(p){
                    cout<<left<<setw(15)<<p->data.id<<"\t\t"<<left<<setw(35)<<p->data.name<<p->data.price<<endl;
                    p=p->next;
                }
                cout<<"----------------------------------------------------------------------"<<endl;
            break;
            case 5:                  //刪除
                cout<<"請您輸入將要刪除的第幾個元素:"<<endl;
                cin>>i;
                ListDelete_L(L,i);
                cout<<"您已經成功刪除第"<<i<<"個數據"<<endl;
                cout<<"新的圖書信息如下所示:"<<endl<<endl;
                cout<<left<<head_1<<left<<"\t\t\t\t"<<head_2<<left<<"\t\t\t"<<head_3<<endl;
                p=L->next;
                while(p){
                    cout<<left<<setw(15)<<p->data.id<<"\t\t"<<left<<setw(35)<<p->data.name<<p->data.price<<endl;
                    p=p->next;
                }
                cout<<"----------------------------------------------------------------------"<<endl;
            break;   
            case 6:                       //輸出
                LinkList p; 
                cout<<"圖書信息如下:"<<endl<<endl;
                cout<<left<<head_1<<left<<"\t\t\t\t"<<head_2<<left<<"\t\t\t"<<head_3<<endl;
                p=L->next;
                while(p){
                    cout<<left<<setw(15)<<p->data.id<<"\t\t"<<left<<setw(35)<<p->data.name<<p->data.price<<endl;
                    p=p->next;
                }
                cout<<"----------------------------------------------------------------------"<<endl;
            break; 
        }
 }
    return 0; 
}