public string Compression(string content)
{
HuffmanNote huffmanNote = CreateHuffmanTree(CreateWordWeightDictionary(content));
Dictionary <char, string> encodeDictionary = new Dictionary <char, string>();
CreateWordCodeDictionay(huffmanNote, "", encodeDictionary);
StringBuilder sb = new StringBuilder(content.Length);
foreach (var item in content)
{
sb.Append(encodeDictionary[item]);
}
string huffmanCode = sb.ToString();
HuffmanTreeInfo huffmanTreeInfo = new HuffmanTreeInfo();
huffmanTreeInfo.ZipCodeRemainder = huffmanCode.Substring(huffmanCode.Length - huffmanCode.Length % 8);
huffmanTreeInfo.ZipCode = HuffmanCodeToByte(huffmanCode.Substring(0, huffmanCode.Length - huffmanCode.Length % 8));
huffmanTreeInfo.UnZipDictionary = CreateUnZipDictionary(encodeDictionary);
return(ObjectToJson(huffmanTreeInfo));
}
private HuffmanNote CreateHuffmanTree(List <HuffmanNote> huffmanNoteList)
{
if (huffmanNoteList.Count == 1)
{
return(huffmanNoteList[0]);
}
var huffmanNoteListBySort = huffmanNoteList.OrderBy(o => o.Weight).ToList();
var minWeight2Note = huffmanNoteListBySort.Take(2).ToList();
huffmanNoteListBySort.RemoveAt(0);
huffmanNoteListBySort.RemoveAt(0);
var leftNote = minWeight2Note[0];
leftNote.HuffmanCode = '0';
var rightNote = minWeight2Note[1];
rightNote.HuffmanCode = '1';
var newNote = new HuffmanNote()
{
LeftNote = leftNote,
RightNote = rightNote,
Weight = leftNote.Weight + rightNote.Weight
};
huffmanNoteListBySort.Add(newNote);
return(CreateHuffmanTree(huffmanNoteListBySort));
}
private void CreateWordCodeDictionay(HuffmanNote huffmanNote, string HuffmanCode, Dictionary <char, string> encodeDictionary)
{
if (huffmanNote.LeftNote == null)
{
encodeDictionary[huffmanNote.Word] = HuffmanCode.Substring(1) + huffmanNote.HuffmanCode;//HuffmanCode.Substring(1) 为什么有这句呢 因为char默认值是\0 所以这里要把第一个字符\0去掉
return;
}
HuffmanCode += huffmanNote.HuffmanCode;
CreateWordCodeDictionay(huffmanNote.LeftNote, HuffmanCode, encodeDictionary);
CreateWordCodeDictionay(huffmanNote.RightNote, HuffmanCode, encodeDictionary);
}
