意外地返回主函數和排序字符串函數

Question

我不知道爲什麼，但此程序奇怪地行爲並返回所有插入的主函數的2或3倍，我不知道是什麼問題。除此之外，我不知道如何在字符串中使用排序選項。我想寫一個函數來完成書的名字。我需要將這個函數（排序函數）添加到主函數中。任何幫助將不勝感激。這是一個程序，它可以獲得書名，作者和翻譯者以及ISBN和主題，並進行搜索或報告。

#include "stdafx.h" 
#include <iostream> 
#include <string> 
#include <vector> 
#include <algorithm> 
using namespace std; 
struct Library 
{ 
    string Book_Name; 
    string Author; 
    string Translator; 
    string ISBN; 
    string Subject; 
    struct Library *fl, *bl; 
}*start, *cur, *p; 

void insert() 
{ 
    p = new struct Library; 
    p->fl = NULL; 
    p->bl = cur; 
    cur->fl = p; 
    cur = p; 
    cout << "Enter the specified informations for Books" << endl; 
    cout << endl; 
    cout << "The Name of the Book " << endl; 
    getline(cin, p->Book_Name); 
    cin.ignore(); 
    cout << "Author" << endl; 
    getline(cin, p->Author); 
    cin.ignore(); 
    cout << "The Name of the Translator " << endl; 
    getline(cin, p->Translator); 
    cin.ignore(); 
    cout << "International Standard Book Number (ISBN) " << endl; 
    getline(cin, p->ISBN); 
    cin.ignore(); 
    cout << "Enter the Subject of the Book " << endl; 
    getline(cin, p->Subject); 
    cin.ignore(); 
} 

void report_number_1() 
{ 
    cout << "The list of all Books in Library are as below" << endl; 
    for (p = start->fl; p != NULL; p = p->fl) 
    { 
     cout << "Book Name " << p->Book_Name << endl; 
     cout << "Author Name " << p->Author << endl; 
     cout << "Translator Name " << p->Translator << endl; 
     cout << "ISBN of the Book " << p->ISBN << endl; 
     cout << "Book Subject " << p->Subject << endl; 
    } 
} 

void delete_number_1() 
{ 
    struct Library *ap, *bp; 
    char is[15]; 
    int sw = 0; 
    cout << "Enter ISBN" << endl; 
    gets_s(is); 
    for (p = start->fl; p != NULL&&!sw; p = p->fl) 
    { 
     if (p->ISBN == is) 
     { 
      sw = 1; 
      ap = p->fl; 
      bp = p->bl; 
      bp->fl = ap; 
      ap->bl = bp; 
      p->fl = NULL; 
      p->bl = NULL; 
     } 
     cout << "Book Name " << p->Book_Name << endl; 
     cout << "Author Name " << p->Author << endl; 
     cout << "Translator Name " << p->Translator << endl; 
     cout << "ISBN of the Book " << p->ISBN << endl; 
     cout << "Book Subject " << p->Subject << endl; 
    } 
} 

void report_number_2() 
{ 
    string title; 
    int sw = 0; 
    cout << "Enter Book's Title " << endl; 
    getline(cin,title); 
    for (p = start->fl; p != NULL; p = p->fl) 
    { 
     if (p->Subject == title) 
     { 
      sw = 1; 
      cout << "Book Name " << p->Book_Name << endl; 
      cout << "Author Name " << p->Author << endl; 
      cout << "Translator Name " << p->Translator << endl; 
      cout << "ISBN of the Book " << p->ISBN << endl; 
      cout << "Book Subject " << p->Subject << endl; 
     } 
     if (!sw) 
     { 
      cout << "ERROR 404 - NOT FOUND" << endl; 
     } 
    } 
} 

void delete_number_2() 
{ 
    struct Library *ap, *bp; 
    string name; 
    int sw = 0; 
    cout << "Enter Author's Name or the Translator's Name so that search begins and delete" << endl; 
    getline(cin,name); 
    for (p = start->fl; p != NULL; p->fl = p) 
    { 
     if ((p->Author == name) || (p->Translator == name)) 
     { 
      sw = 1; 
      ap = p->fl; 
      bp = p->bl; 
      bp->fl = ap; 
      ap->bl = bp; 
      p->fl = NULL; 
      p->bl = NULL; 
     } 
     cout << "Book Name " << p->Book_Name << endl; 
     cout << "Author Name " << p->Author << endl; 
     cout << "Translator Name " << p->Translator << endl; 
     cout << "ISBN of the Book " << p->ISBN << endl; 
     cout << "Book Subject " << p->Subject << endl; 
     delete(p); 
    } 
    if (!sw) 
    { 
     cout << "ERROR 404 - NOT FOUND" << endl; 
    } 
} 

void main() 
{ 
    char ch; 
    start = new struct Library; 
    start->fl = NULL; 
    start->bl = NULL; 
    cur = start; 
    do 
    { 
     cout << "Enter I/i for Insert " << endl; 
     cout << "Enter R/r for Report that is Sorted by Name of the Book " << endl; 
     cout << "Enter S/s for Search by ISBN and delete the Specific Book " << endl; 
     cout << "Enter U/u for search " << endl; 
     cout << "Enter W/w to delete the Specific Book" << endl; 
     cout << "Enter X/x for Terminating the Program " << endl; 
     cin >> ch; 
     switch (ch) 
     { 
     case 'I': 
     case 'i': 
      insert(); 
      break; 
     case'R': 
     case'r': 
      report_number_1(); 
     case 'S': 
     case 's': 
      delete_number_1(); 
      break; 
     case 'U': 
     case 'u': 
      report_number_2(); 
      break; 
     case 'W': 
     case 'w': 
      delete_number_2(); 
      break; 
     } 
    } while (ch != 'X' && ch != 'x'); 
} 

Answer 1

我行承擔

for (p = start->fl; p != NULL; p->fl = p) 

在delete_number_2（）的for循環的最後一部分應該是

p = p->fl