Homework Books

#include <iostream>
#include <cstring>
#include <vector>
#include <algorithm>

using namespace std;

struct Book
{
    char name[20];
    char author[20];
    char publisher[20];
    char genre[20];
};

void PrintByIndex(const vector<Book>& b, const size_t index);

int main()
{
    const unsigned int NumberOfElements = 10;
    const string items[] =
    {
      "1. Редактировать",
      "2. Напечатать все",
      "3. Найти по автору",
      "4. Найти по названию",
      "5. Сортировать по имени",
      "6. Сортировать по автору",
      "7. Сортировать по издателю",
    };

    unsigned int key;
    unsigned int book_number;

    string author;
    string name;

    vector<Book> books(NumberOfElements);

    for (auto& value : books) 
    {
        cout << "Имя, автор, издатель, жанр: ";
        gets_s(value.name);
        gets_s(value.author);
        gets_s(value.publisher);
        gets_s(value.genre);
    }


    while (true) 
    {
        for (const auto& value : items)
        {
            cout << value << endl;
        }

        cout << ">> ";
        cin >> key;

        switch (key) 
        {
        case 1:
            cout << "Номер книги: ";
            cin >> book_number;
            cout << "Новое имя, автор, издатель, жанр: ";
            gets_s(books[book_number].name);
            gets_s(books[book_number].author);
            gets_s(books[book_number].publisher);
            gets_s(books[book_number].genre);
            break;
        case 2:
            for (size_t i = 0; i < NumberOfElements; ++i)
            {
                PrintByIndex(books, i);
            }
            break;
        case 3:
            cout << "Автор: ";
            cin >> author;
            for (size_t i = 0; i < NumberOfElements; ++i)
            {
                if (books[i].author == author)
                {
                    PrintByIndex(books, i);
                }
            }
            break;
        case 4:
            cout << "Название: ";
            cin >> name;
            for (size_t i = 0; i < NumberOfElements; ++i)
            {
                if (books[i].name == name)
                {
                    PrintByIndex(books, i);
                }
            }
            break;
        case 5:
            sort(books.begin(), books.end(), [](const Book& b1, const Book& b2) { return b1.name < b2.name; });
            break;
        case 6:
            sort(books.begin(), books.end(), [](const Book& b1, const Book& b2) { return b1.author < b2.author; });
            break;
        case 7:
            sort(books.begin(), books.end(), [](const Book& b1, const Book& b2) { return b1.publisher < b2.publisher; });
            break;

        default:
            break;
        }
    }
}

void PrintByIndex(const vector<Book>& b, const size_t index)
{
    cout << "[" << index << "] "
        << b[index].name << " " << b[index].author << " "
        << b[index].publisher << " " << b[index].genre << endl;
}