void insertionSort(Array<Book>& ob)
{
    for (int i = 0; i < ob.length(); ++i)
        for (int j = i; j > 0 && ob[j - 1] < ob[j]; --j)
        {
            Book temp = ob[j - 1];
            ob[j - 1] = ob[j];
            ob[j] = temp;
        }
}