public override void DoPOT(IHuffmanTreeVisitor visitor)
{
HuffmanTreeNode node = root;
int level = 0;
Stack <HuffmanTreeNode> stack = new Stack <HuffmanTreeNode>();
while (true)
{
if (node != null)
{
stack.Push(node);
node = node.Left;
visitor.VisitLeftEdge(++level);
}
else
{
if (stack.Count == 0)
{
return;
}
if (stack.Peek().Right == null)
{
visitor.VisitBackEdge(--level);
node = stack.Pop();
if (node.IsLeaf)
{
visitor.VisitNode(node);
}
while (stack.Count != 0 && node == stack.Peek().Right)
{
visitor.VisitBackEdge(--level);
node = stack.Pop();
if (node.IsLeaf)
{
visitor.VisitNode(node);
}
}
}
if (stack.Count != 0)
{
node = stack.Peek().Right;
visitor.VisitRightEdge(level);
}
else
{
node = null;
}
}
}
}
public override void DoBFS(IHuffmanTreeVisitor visitor)
{
Guard.IsNotNull(visitor, nameof(visitor));
Queue <HuffmanTreeNode> bfsQueue = new Queue <HuffmanTreeNode>(64);
bfsQueue.Enqueue(root);
while (bfsQueue.Count != 0)
{
HuffmanTreeNode node = bfsQueue.Dequeue();
visitor.VisitNode(node);
if (node == null)
{
continue;
}
bfsQueue.Enqueue(node.Left);
bfsQueue.Enqueue(node.Right);
}
}
public TreeWalkStep VisitNode(HuffmanTreeNode node)
{
if (node.IsLeaf)
{
output.WriteSymbol(node.Value.Symbol);
if (tree.IsRoot(node))
{
if (input.ReadBit(out Bit _))
{
seqLength--;
}
}
return(TreeWalkStep.Finish);
}
if (!input.ReadBit(out Bit bit))
{
throw new ArgumentException();
}
seqLength--;
return(bit == Bit.Zero ? TreeWalkStep.ToLeft : TreeWalkStep.ToRight);
}
public HuffmanTreeBase BuildHuffmanTree(WeightsTable weightsTable)
{
Guard.IsNotNull(weightsTable, nameof(weightsTable));
HuffmanTreeNodePriorityQueue priorityQueue = new HuffmanTreeNodePriorityQueue();
foreach (WeightedSymbol weightedSymbol in weightsTable)
{
priorityQueue.Insert(weightedSymbol.Weight, new HuffmanTreeNode(weightedSymbol));
}
if (priorityQueue.Size == 0)
{
return(EmptyHuffmanTree.Instance);
}
while (priorityQueue.Size > 1)
{
var lNode = priorityQueue.DeleteMinimumValue();
var rNode = priorityQueue.DeleteMinimumValue();
long weight = lNode.Value.Weight + rNode.Value.Weight;
var internalNode = new HuffmanTreeNode(new WeightedSymbol(0, weight), lNode, rNode);
priorityQueue.Insert(weight, internalNode);
}
return(new HuffmanTree(priorityQueue.GetMinimumValue()));
}
public override bool Walk(IHuffmanTreeWalker walker)
{
HuffmanTreeNode node = root;
while (node != null)
{
TreeWalkStep walkStep = walker.VisitNode(node);
switch (walkStep)
{
case TreeWalkStep.ToLeft:
node = node.Left;
break;
case TreeWalkStep.ToRight:
node = node.Right;
break;
case TreeWalkStep.Finish: return(true);
default: throw new StreamFormatException();
}
}
return(false);
}
public void VisitNode(HuffmanTreeNode node)
{
codingTable[node.Value.Symbol] = bitSequence.Clone();
}
public abstract bool IsRoot(HuffmanTreeNode node);
public override bool IsRoot(HuffmanTreeNode node)
{
return(ReferenceEquals(node, root));
}
public HuffmanTree(HuffmanTreeNode root)
{
Guard.IsNotNull(root, nameof(root));
this.root = root;
}
public HuffmanTreeNode(WeightedSymbol value, HuffmanTreeNode left = null, HuffmanTreeNode right = null)
{
Value = value;
Left = left;
Right = right;
}
public override bool IsRoot(HuffmanTreeNode node)
{
return(false);
}