I want to delete a specific book

[GvCkjE8b]

Hello guys, I'm new to C++ and right now I'm doing homework, making programs that i have think of and etc to train myself. Now I made "Library Management", but I want my program do delete specific books that are in the txt file not all books like what I have made. I had been searching something for days, trying to make something but it never works. So can anyone help me with this ? Thank you very much!
Here is my code

#include <iostream>
#include <cstdlib>
#include <fstream>
#include <string>
using namespace std;
string choice; //CHOICE FOR GOING BACK OR TO EXIT
int MenuChoice; //CHOICE FOR THE MENU
fstream outfile; 

//MAIN MENU
void menu(){
    cout << "\t\t\tLibrary Management" << endl;
    cout << "\t\t\tMAIN MENU" << endl;
    cout << "\t\t\t1. Add books" <<endl;
    cout << "\t\t\t2. Delete all record"<<endl;
    cout << "\t\t\t3. View book list" << endl;
    cout << "\t\t\t4. Exit" << endl;
}
//ADD BOOKS MENU
void AddBooks(){
    int DateOfPublishing, ID;
    string BookCategory, BookTitle, BookAuthor;
    cout << "Book ID: "; 
    cin >> ID;
    cout << "Book Category: ";
    cin >> BookCategory;
    cout << "Book Title: "; 
    cin >> BookTitle;
    cout << "Book Author: "; 
    cin >> BookAuthor;
    cout << "Date of Publishing: "; 
    cin >> DateOfPublishing;

    ofstream outfile("Library.txt", ios::out | ios::app);
    cout << "Would you like to add a new book (Y/N)";
    cin >> choice;
    if (choice == "Y" || choice=="y"){
        AddBooks();
    }
    outfile << "Books ID: " <<ID << " " << "Book Category: " << BookCategory <<" "<< "Book Title: " << BookAuthor
    <<" " << "Date of Publishing: " << DateOfPublishing << endl;
    outfile.close();
}
//DELETE ALL BOOKS MENU
void DeleteBooks()
{
    outfile.open("Library.txt");
    ofstream outfile("Library.txt",ios::trunc);
    outfile.close();
    cout << "All books have been deleted!"<<endl;
    cout << "Woud you like to go back (Y/N)?";
}
//LIST OF THE BOOKS YOU HAD ADDED
void BookList(){
    string line;
    fstream outfile ("Library.txt", ios::in | ios::out);
        if (outfile.is_open())
        {
            while (! outfile.eof() ){
                getline(outfile,line);
                cout << line << endl;
            }
            outfile.close();
        }
        else{
            cout << "Unable to open file.";
        }
}

int main(){
    menu();
    cout <<"\t\t\tPlease write your choice: "; //CHOICE FOR THE MENU
    cin >> MenuChoice;

    if (MenuChoice == 1){
        system ("CLS");
        AddBooks();
    }
    if (MenuChoice==2)
    {
        system("CLS");
        DeleteBooks();
        cin >> choice;
        for (int i=1; i++;){
        if (choice == "Y" || choice == "y"){
            system("CLS");
            return main();
        }
        if (choice == "N" || choice == "n"){
            return 0;
        }
        if (choice != "Y" || choice != "y" || choice != "N" || choice != "n"){
            cout << "Sorry you need to choose (Y/N) ";
            cin.ignore();
            cin >> choice;
        }
        }
    }

    if (MenuChoice == 3){
        system ("CLS");
        BookList();
        cout << "Would you like to go back to the menu (Y) or to exit (N) ? ";
        cin >> choice;
        for (int i=1; i++;){
        if (choice == "Y" || choice == "y"){
            system("CLS");
            return main();
        }
        if (choice == "N" || choice == "n"){
            return 0;
        }
        if (choice != "Y" || choice != "y" || choice != "N" || choice != "n"){
            cout << "Sorry you need to choose (Y/N) ";
            cin.ignore();
            cin >> choice;
        }
        }

    }

    if (MenuChoice == 4){
        cout << "Are you sure to exit (Y/N)";
        cin >> choice;
        for (int i=1;i++;){
            if (choice=="Y"||choice=="y"){
                return 0;
            }
            if (choice=="N"||choice=="n"){
                system("CLS");
                main();
            }
            if (choice != "Y" || choice != "y" || choice != "N" || choice != "n"){
            cout << "Sorry you need to choose (Y/N) ";
            cin.ignore();
            cin >> choice;
        }
        }
    }
    if (MenuChoice!=1||MenuChoice!=2||MenuChoice!=3||MenuChoice!=4||MenuChoice!=5){
        system("CLS");
        main();
    }
}

[dhayden]

Copy library.txt to a temporary file, omitting the book that you want to delete. Then rename the temporary file to library.txt. You may need to delete library.txt first.