Question

MUST BE WRITTEN IN C++

Objective: Learn how to define structures and classes, create and access a vector of structures, use sort with different compare functions.

Assignment:

Your program will use the same input file, but you will print the whole book information, not just the title. And, most importantly, this time you will take an object oriented approach to this problem.

Detailed specifications:

• Define a class named Collection, in which you will define a structure that can hold book information. Remember that a structure is the definition of a type, so you need to declare a vector of Books to actually store the data from the file.

class Collection
{
    private:
        struct Book
        {
            string title;
            string author;
            string genre;
        };
        vector books;

    public:   
 
    void sortByTitle()
    {
        sort(books.begin(), books.end(), [](Book b1, Book b2) { return b1.title < b2.title; });
    }
};

• In the public section of your class you will need:
  • A constructor that will read the file and populate the vector. Read the each line of the file the same way you did in Lab 1, making it a string stream, but now you will need to call getline on the stringstream repeatedly to get each part following the title. After populating a structure variable with the book info, push it into the vector. Make sure to test the the file was loaded successfully to avoid sorting an empty vector later.
  • A function to print the data on the screen. Use a range-based for loop to print.
  • Three sorting functions that will sort the data by title, author and genre. The sortByTitle function is provided above as an example.
• In the main function, design an interface to test your class. Let the user of your program choose which field they want to see the books sorted by. You will sort the authors according to the user's choice and print. Always print ALL the fields regardless of how the books are sorted. Keep in mind that when I test your program I will want to test all three sorting options.

Submit two files: main.cpp with your main function and Collection.h with your class implementation.

CONTENT OF GIVEN INPUT FILE CALLED "Books.txt"

Starting out with c++, Tony Gaddis, technical

Fundamentals of Database Systems, Elmarsi & Navathe, technical

The C++ Programming Language, Bjarne Stroustrup, technical

The Pillars of the Earth, Ken Follett, historical fiction

Fall of Giants, Ken Follet, historical fiction

Mindset: The New Psychology of Success, Carol Dweck, psychology

One Hundred Years of Solitude, Gabriel Garcia Marquez, fiction

Ashes, Kenzo Kitakana, fiction

The Dark Forest, Liu Cixin, science fiction

Replay, Ken Grimwood, fantasy

Answer 1

// collection.h

#ifndef COLLECTION_H_

#define COLLECTION_H_

#include <vector>

#include <iostream>

#include <algorithm>

#include <fstream>

#include <sstream>

#include <iomanip>

using namespace std;

class Collection

{

       private:

        struct Book

        {

            string title;

            string author;

            string genre;

        };

        vector<Book> books;

    public:

       Collection()

       {

          string fileName, line;

          Book book;

          ifstream fin;

          cout<<"Enter filename : ";

          cin>>fileName;

          fin.open(fileName.c_str());

              // loop to continually input file name/path until valid input has not been received

              while(!fin.is_open())

              {

                    cout<<"Unable to open : "<<fileName<<endl;

                    cout<<"Enter valid file name/path : ";

                    cin>>fileName;

                    fin.open(fileName.c_str());

              }

              // read till the end of file

              while(!fin.eof())

              {

                    getline(fin,line); // read a line from file

                    stringstream lineStream(line);

                    // extract the title field from the line

                    getline(lineStream,book.title,',');

                    // extract the author field from the line

                    getline(lineStream,book.author,',');

                    // extract the genre field from the line

                    getline(lineStream,book.genre);

                    if(!fin.eof())

                           book.genre = book.genre.substr(0,book.genre.length()-1);

                    // insert the title into the vector

                    books.push_back(book);

              }

                    // close the file

                    fin.close();

       }

       // function to sort the vector of books by title

       void sortByTitle()

       {

          sort(books.begin(), books.end(), [](Book b1, Book b2) { return b1.title < b2.title; });

       }

       // function to sort the vector of books by author

       void sortByAuthor()

       {

          sort(books.begin(),books.end(),[](Book b1, Book b2) {return b1.author < b2.author; });

       }

       // function to sort the vector of books by genre

       void sortByGenre()

       {

          sort(books.begin(),books.end(),[](Book b1, Book b2) {return b1.genre < b2.genre; });

       }

       // function to print the details of the books

       void print()

       {

          // loop over the vector

          cout<<left<<setw(50)<<"Title"<<left<<setw(35)<<"Author"<<left<<setw(15)<<"Genre"<<endl;

          cout<<string(100,'-')<<endl;

          for(unsigned int i=0;i<books.size();i++)

          {

                cout<<left<<setw(50)<<books[i].title<<left<<setw(35)<<books[i].author<<left<<setw(15)<<books[i].genre<<endl;

          }

       }

};

#endif /* COLLECTION_H_ */

//end of collection.h

//main.cpp: C++ program to test the Collection class

#include <iostream>

#include "collection.h"

using namespace std;

int main() {

       Collection collection;

       int choice;

       cout<<"\nMenu"<<endl;

       cout<<"1. Sort by title"<<endl;

       cout<<"2. Sort by author"<<endl;

       cout<<"3. Sort by genre"<<endl;

       cout<<"Enter you choice(1-3) : ";

       cin>>choice;

       // sort the books based on the user’s choice

       if(choice == 1)

             collection.sortByTitle();

       else if(choice == 2)

             collection.sortByAuthor();

       else if(choice == 3)

             collection.sortByGenre();

       else

             cout<<"Invalid choice"<<endl;

       cout<<"Books : "<<endl;

       collection.print(); // print the books

       return 0;

}

//end of program

Output:

Input file:

Output: