private Dictionary<char, string> CreateHuffmanDict(string code,HuffmanTreeNode hTree)
{
Dictionary<char, string> result = new Dictionary<char, string>();
//如果是叶子节点，那么传入的code就是它的哈夫曼编码
if (hTree.LChild == null && hTree.RChild == null)
{
result.Add(hTree.Value, code);
}
else
{
//否则，约定左边的0，右边的1
var dictL = CreateHuffmanDict(code + "0", hTree.LChild);
var dictR = CreateHuffmanDict(code + "1", hTree.RChild);
foreach (var item in dictL)
{
result.Add(item.Key, item.Value);
}
foreach (var item in dictR)
{
result.Add(item.Key, item.Value);
}
}
return result;
}
private HuffmanTreeNode CreateHuffmanTree(HuffmanTreeNode[] sources)
{
HuffmanTreeNode topNode = null;
HuffmanTreeNode[] nodes = sources;
bool bIsNext = true;
while (bIsNext)
{
//先排序
Array.Sort(nodes);
//如果只有（或只剩下两个未处理节点），则分别作为左右节点。
//因为已经排序，所以左节点的值小于右节点的值。
if (nodes.Count() == 2)
{
topNode = new HuffmanTreeNode();
topNode.LChild = nodes[0];
topNode.RChild = nodes[1];
bIsNext = false;
}
HuffmanTreeNode node1 = sources[sources.Length - 1];
HuffmanTreeNode node2 = sources[sources.Length - 2];
HuffmanTreeNode tmpNode = new HuffmanTreeNode();
tmpNode.Weight = node1.Weight + node2.Weight;
tmpNode.LChild = node1;
tmpNode.RChild = node2;
HuffmanTreeNode[] tmpNds = new HuffmanTreeNode[nodes.Length - 1];
Array.Copy(nodes, 0, tmpNds, 0, nodes.Length - 1);
tmpNds[tmpNds.Length - 1] = tmpNode;
nodes = tmpNds;
}
return topNode;
}
public Dictionary<char, string> CreateHuffmanDict(HuffmanTreeNode hTree)
{
return CreateHuffmanDict("", hTree);
}
