/// <summary>
///
/// </summary>
/// <param name="nodes"></param>
/// <returns></returns>
private static HuffmanNode ConstructHuffmanTree(ICollection <HuffmanNode> nodes)
{
if (nodes.Count < 2)
{
return(nodes.First()); //finished
}
var left = nodes.Pop();
var right = nodes.Pop();
var node = new HuffmanNode(left, right);
return(ConstructHuffmanTree(nodes.AddSorted(node)));
}