/// <summary>
/// Merges two lists of copies. Each time when the book from list "b" is inserted into the list "a",
/// it is put into the right place by a comparer
/// First we try to insert the book at the end of the list "a", then we try to insert it into other place.
/// </summary>
/// <param name="a"></param>
/// <param name="b"></param>
/// <returns></returns>
public List <Copy> Merge(List <Copy> a, List <Copy> b)
{
BookSorter bookSorter = new BookSorter();
int i = 0;
int j = a.Count - 1;
foreach (Copy copy in b)
{
while (true)
{
if (bookSorter.Compare(a[j], b[i]) == -1 && j != 0)
{
j--;
continue;
}
a.Insert(j, b[i]);
j = a.Count - 1;
i++;
break;
}
}
return(a);
}
public List <Copy> MergeSort(List <Copy> filter, int count)
{
BookSorter bookSorter = new BookSorter();
if (count == 1)
{
filter.Sort(bookSorter);
return(filter);
}
int temp = count / 2;
count -= temp;
List <Copy> first = filter.GetRange(0, filter.Count / 2);
List <Copy> second = filter.GetRange(filter.Count / 2, filter.Count / 2);
Thread thread = new Thread(() => second = MergeSort(second, count));
thread.Start();
first = MergeSort(first, count);
thread.Join();
return(Merge(first, second));
}
