Biblioteka

struct Book
{
    char* author;
    char* name;
    int year;
};

void menu()
{
    printf("\n1: Добавить книгу\n");
    printf("2: Сортировать библиотеку\n");
    printf("3: Выход\n");
}

int init_str(char * &s) {
    int i = 0;
    while ((s[i] = getchar()) != '\n') {
        s = (char *)realloc(s, sizeof(char)*(i + 2));
        if (!s)
            exit(-1);
        i++;
    }
    s[i] = '\0';
    return i;
}


void add_book(Book* &books, int &count)
{
    if (books == NULL)
        books = (Book*)malloc(sizeof(Book));
    else
    {
        books = (Book*)realloc(books, count + 1);
    }
    count++;
    printf("Введите название книги\n");
    rewind(stdin);
    books[count - 1].name = (char*)malloc(sizeof(char));
    init_str(books[count - 1].name);
    printf("Введите автора книги\n");
    rewind(stdin);
    books[count - 1].author = (char*)malloc(sizeof(char));
    init_str(books[count - 1].author);
    printf("Введите год\n");
    while (!scanf("%d", &books[count - 1].year) || books[count - 1].year > 2020 || books[count - 1].year < 0)
        rewind(stdin);

}

void sort_books(Book* &books, int b, int e)
{
    int l = b, r = e;
    int piv = books[(l + r) / 2].year;
    while (l <= r)
    {
        while (books[l].year < piv)
            l++;
        while (books[r].year > piv)
            r--;
        if (l <= r)
        {
            Book tmp = books[l];
            books[l] = books[r];
            books[r] = tmp;
            l++;
            r--;
        }
    }
    if (b < r)
        sort_books(books, b, r);
    if (e > l)
        sort_books(books, l, e);

}

int main()
{
    int choice;
    Book* books = NULL;
    int books_c = 0;
    while (true)
    {
        system("CLS");
        menu();
        scanf("%d", &choice);
        switch (choice)
        {
        case 1: add_book(books, books_c);
            break;
        case 2:
            sort_books(books,0,books_c-1);
            break;
        default:
            printf("Неправильный выбор\n");
            break;
        }
    }
}