private static List <T> Merge <T>(List <T> list, int chunkCount, int chunkSize, IComparer <T> comparer)
{
int[] chunkIndexes = new int[chunkCount];
int[] chunkEnds = new int[chunkCount];
for (int i = 0; i < chunkCount; i++)
{
chunkIndexes[i] = i * chunkSize;
chunkEnds[i] = i * chunkSize + chunkSize;
}
chunkEnds[chunkEnds.Length - 1] = list.Count;
MinHeap <int> heap = new MinHeap <int>(chunkCount,
new SelectComparer <int, T>(i => list[chunkIndexes[i]], comparer));
for (int i = 0; i < chunkCount; i++)
{
heap.Add(i);
}
List <T> result = new List <T>(list.Count);
for (int i = 0; i < list.Count; i++)
{
result.Add(list[chunkIndexes[heap.Root]]);
chunkIndexes[heap.Root]++;
if (chunkIndexes[heap.Root] == chunkEnds[heap.Root])
{
heap.Extract();
}
else
{
heap.DownHeap();
}
}
return(result);
}
