private List <bool> GetCode(char s, AdaptiveHuffmanNode node, List <bool> code = null)
{
if (code == null)
{
code = new List <bool>();
}
if (node.left == null && node.right == null)
{
return(node.symbol == s ? code : new List <bool>());
}
else
{
List <bool> temp = new List <bool>();
if (node.left != null)
{
var l = new List <bool>();
l.AddRange(code);
l.Add(false);
temp = GetCode(s, node.left, l);
}
if (temp.Count == 0 && node.right != null)
{
var l = new List <bool>();
l.AddRange(code);
l.Add(true);
temp = GetCode(s, node.right, l);
}
return(temp);
}
}
private void SwapNode(AdaptiveHuffmanNode n1, AdaptiveHuffmanNode n2)
{
var i1 = nodes.IndexOf(n1);
var i2 = nodes.IndexOf(n2);
var temp = nodes[i1];
nodes[i1] = nodes[i2];
nodes[i2] = temp;
var tmp_parent = n1.parent;
n1.parent = n2.parent;
n2.parent = tmp_parent;
if (n1.parent.left == n2)
{
n1.parent.left = n1;
}
else
{
n1.parent.right = n1;
}
if (n2.parent.left == n1)
{
n2.parent.left = n2;
}
else
{
n2.parent.right = n2;
}
}
public AdaptiveHuffmanEncoder()
{
NYT = new AdaptiveHuffmanNode()
{
symbol = char.MaxValue
};
root = NYT;
nodes = new List <AdaptiveHuffmanNode>();
seen = new List <AdaptiveHuffmanNode>();
for (int i = 0; i < 256; i++)
{
seen.Add(null);
}
}
private void Insert(char s)
{
AdaptiveHuffmanNode node = seen[s];
if (node == null)
{
AdaptiveHuffmanNode spawn = new AdaptiveHuffmanNode()
{
symbol = s, weight = 1
};
AdaptiveHuffmanNode internalNode = new AdaptiveHuffmanNode()
{
symbol = null, weight = 1, parent = NYT.parent, left = NYT, right = spawn
};
spawn.parent = internalNode;
NYT.parent = internalNode;
if (internalNode.parent != null)
{
internalNode.parent.left = internalNode;
}
else
{
root = internalNode;
}
nodes.Insert(0, internalNode);
nodes.Insert(0, spawn);
seen[s] = spawn;
node = internalNode.parent;
}
while (node != null)
{
AdaptiveHuffmanNode largest = FindLargestNode(node.weight);
if (node != largest && node != largest.parent && largest != node.parent)
{
SwapNode(node, largest);
}
node.weight++;
node = node.parent;
}
}