Beispiel #1
0
        private static LinkedNode BuildList(byte[] primeData)
        {
            LinkedNode root;

            root = new LinkedNode(256, 1);
            root = root.Insert(new LinkedNode(257, 1));

            for (var i = 0; i < primeData.Length; i++)
            {
                if (primeData[i] != 0)
                {
                    root = root.Insert(new LinkedNode(i, primeData[i]));
                }
            }

            return(root);
        }
Beispiel #2
0
        private static LinkedNode Decode(BitStream input, LinkedNode head)
        {
            var node = head;

            while (node.Child0 != null)
            {
                var bit = input.ReadBits(1);
                if (bit == -1)
                {
                    throw new Exception("Unexpected end of file");
                }

                node = bit == 0 ? node.Child0 : node.Child1;
            }

            return(node);
        }
Beispiel #3
0
        private static LinkedNode BuildTree(LinkedNode tail)
        {
            var current = tail;

            while (current != null)
            {
                var child0 = current;
                var child1 = current.Prev;
                if (child1 == null)
                {
                    break;
                }

                var parent = new LinkedNode(0, child0.Weight + child1.Weight);
                parent.Child0 = child0;
                child0.Parent = parent;
                child1.Parent = parent;

                current.Insert(parent);
                current = current.Prev.Prev;
            }

            return(current);
        }
Beispiel #4
0
        // This increases the weight of the new node and its antecendants
        // and adjusts the tree if needed
        private static void AdjustTree(LinkedNode newNode)
        {
            var current = newNode;

            while (current != null)
            {
                current.Weight++;
                LinkedNode insertpoint;
                LinkedNode prev;

                // Go backwards thru the list looking for the insertion point
                insertpoint = current;
                while (true)
                {
                    prev = insertpoint.Prev;
                    if (prev == null)
                    {
                        break;
                    }

                    if (prev.Weight >= current.Weight)
                    {
                        break;
                    }

                    insertpoint = prev;
                }

                // No insertion point found
                if (insertpoint == current)
                {
                    current = current.Parent;
                    continue;
                }

                // The following code basicly swaps insertpoint with current

                // remove insert point
                if (insertpoint.Prev != null)
                {
                    insertpoint.Prev.Next = insertpoint.Next;
                }

                insertpoint.Next.Prev = insertpoint.Prev;

                // Insert insertpoint after current
                insertpoint.Next = current.Next;
                insertpoint.Prev = current;
                if (current.Next != null)
                {
                    current.Next.Prev = insertpoint;
                }

                current.Next = insertpoint;

                // remove current
                current.Prev.Next = current.Next;
                current.Next.Prev = current.Prev;

                // insert current after prev
                var temp = prev.Next;
                current.Next = temp;
                current.Prev = prev;
                temp.Prev    = current;
                prev.Next    = current;

                // Set up parent/child links
                var currentparent = current.Parent;
                var insertparent  = insertpoint.Parent;

                if (currentparent.Child0 == current)
                {
                    currentparent.Child0 = insertpoint;
                }

                if (currentparent != insertparent && insertparent.Child0 == insertpoint)
                {
                    insertparent.Child0 = current;
                }

                current.Parent     = insertparent;
                insertpoint.Parent = currentparent;

                current = current.Parent;
            }
        }