LZW算法的 C#实现
#undef debug
#define debugdisplay
#undef debugdictionary
using System;
using System.Collections;
namespace LZW
{
public class cLZW
{
#region Constrcut
public cLZW()
{
}
#endregion
#region Coding
public string InCharStream
{
set { _InCharStream = value; }
get {return _InCharStream; }
}
public ArrayList CodingCodeStream
{
get {return _CodingCodeStream;}
}
public ArrayList CodingDictionary
{
get {return _CodingDictionary;}
}
private void InitCodingDictionary()
{
_CodingDictionary.Clear();
#if debug
_CodingDictionary.Add("A");
_CodingDictionary.Add("B");
_CodingDictionary.Add("C");
#else
for(int i = 0; i < 256; i++)
{
_CodingDictionary.Add((char)i);
}
#endif
}
private void AddCodingDictionary(object str)
{
_CodingDictionary.Add(str);
}
private void AddCodingCodeStream(object str)
{
_CodingCodeStream.Add(str);
}
private bool ISInCodingDictionary(string Prefix)
{
bool result = false;
int count = _CodingDictionary.Count;
for(int i = 0; i < count; i++)
{
string temp = _CodingDictionary[i].ToString();
if (temp.IndexOf(Prefix) >= 0)
{
result = true;
break;
}
}
return result;
}
private string GetIndexCodingDictionary(string Prefix)
{
string result ="0";
int count = _CodingDictionary.Count;
for(int i = 0; i < count; i++)
{
string temp = _CodingDictionary[i].ToString();
if (temp.IndexOf(Prefix) >= 0)
{
result = Convert.ToString(i + 1);
break;
}
}
return result;
}
private void DisplayCodingCodeStream()
{
System.Console.WriteLine("*********_CodingCodeStream************");
for(int i = 0; i < _CodingCodeStream.Count; i++)
{
System.Console.WriteLine(_CodingCodeStream[i].ToString());
}
}
private void DisplayCodingDictionary()
{
System.Console.WriteLine("*********_CodingDictionary************");
for(int i = 0; i < _CodingDictionary.Count; i++)
{
System.Console.WriteLine(_CodingDictionary[i].ToString());
}
}
private void DisplayInCharStream()
{
System.Console.WriteLine("*********_InCharStream************");
System.Console.WriteLine(_InCharStream);
}
private void InitCodingCodeStream()
{
_CodingCodeStream.Clear();
}
private ArrayList _CodingDictionary = new ArrayList();
private string _InCharStream = "";
private ArrayList _CodingCodeStream = new ArrayList();
public void Coding()
{
string Prefix ="" ;
string c ="";
string PrefixIndex= "0";
int count = _InCharStream.Length;
if (count == 0) return ;
InitCodingDictionary();
InitCodingCodeStream();
Prefix = _InCharStream[0].ToString();
for(int i = 1; i < count; i++)
{
c = _InCharStream[i].ToString();
if (ISInCodingDictionary( Prefix + c))
{
Prefix += c;
}
else
{
PrefixIndex = GetIndexCodingDictionary(Prefix);
AddCodingCodeStream(PrefixIndex);
AddCodingDictionary( Prefix + c);
Prefix = c;
}
}
PrefixIndex = GetIndexCodingDictionary(Prefix);
AddCodingCodeStream(PrefixIndex);
#if debugdisplay
DisplayInCharStream();
DisplayCodingCodeStream();
#if debugdictionary
DisplayCodingDictionary();
#endif
#endif
}
#endregion
#region Decode
private ArrayList _DeCodeDictionary = new ArrayList();
private ArrayList _OutCharStream = new ArrayList();
private int[] _DeCodeCodeStream ;
public void SetDeCodeSCodetream(int[] obj)
{
int count = obj.Length;
_DeCodeCodeStream = new int[count];
for(int i =0; i < count ; i++)
{
_DeCodeCodeStream[i] = obj[i];
}
}
public void SetDeCodeSCodetream(ArrayList obj)
{
int count = obj.Count;
_DeCodeCodeStream = new int[count];
for(int i =0; i < count ; i++)
{
_DeCodeCodeStream[i] = System.Convert.ToInt32(obj[i]);
}
}
public int[] GetDeCodeCodeStream()
{
return _DeCodeCodeStream;
}
public string OutCharStream
{
get
{
string result = "";
for(int i = 0,count = _OutCharStream.Count; i < count; i++)
{
result += _OutCharStream[i].ToString();
}
return result;
}
}
public ArrayList DeCodeDictionary
{
get
{
return _DeCodeDictionary;
}
}
private void InitDeCodeDictionary()
{
_DeCodeDictionary.Clear();
#if debug
_DeCodeDictionary.Add("A");
_DeCodeDictionary.Add("B");
_DeCodeDictionary.Add("C");
#else
for(int i = 0; i < 256; i++)
{
_DeCodeDictionary.Add((char)i);
}
#endif
}
private void InitOutCharStream()
{
_OutCharStream.Clear();
}
private void DisplayOutCharStream()
{
System.Console.WriteLine("*********_OutCharStream************");
string temp = "";
for(int i = 0; i < _OutCharStream.Count; i++)
{
temp = temp + (_OutCharStream[i].ToString());
}
System.Console.WriteLine(temp);
}
private void DisplayDeCodeDictionary()
{
System.Console.WriteLine("*********_DeCodeDictionary************");
for(int i = 0; i < _DeCodeDictionary.Count; i++)
{
System.Console.WriteLine(_DeCodeDictionary[i].ToString());
}
}
private void DisplayDeCodeCodeStream()
{
System.Console.WriteLine("*********_DeCodeCodeStream************");
int count = _DeCodeCodeStream.Length;
for(int i = 0; i < count; i++)
{
System.Console.WriteLine("{0}",_DeCodeCodeStream[i]);
}
}
private void AddOutCharStream(object str)
{
_OutCharStream.Add(str);
}
private void AddDeCodeDictionary(object str)
{
_DeCodeDictionary.Add(str);
}
private bool ISInDeCodeDictionary(int cw)
{
bool result = false;
int count = _DeCodeDictionary.Count;
if (cw <= count - 1)
{
result = true;
}
return result;
}
public void Decode()
{
InitDeCodeDictionary();
InitOutCharStream();
int cw = 0;
int pw = 0;
string Prefix = "";
string c="";
cw = _DeCodeCodeStream[0] - 1;
this.AddOutCharStream(this._DeCodeDictionary[cw]);
pw = cw;
int count = _DeCodeCodeStream.Length;
if (count == 0) return;
for(int i = 1; i < count; i++)
{
cw = _DeCodeCodeStream[i] - 1;
if (ISInDeCodeDictionary(cw))
{
this.AddOutCharStream(this._DeCodeDictionary[cw]);
Prefix = this._DeCodeDictionary[pw].ToString();
c = (this._DeCodeDictionary[cw].ToString())[0].ToString();
this.AddDeCodeDictionary(Prefix + c);
}
else
{
Prefix = this._DeCodeDictionary[pw].ToString();
c = Prefix[0].ToString();
this.AddOutCharStream(Prefix + c);
this.AddDeCodeDictionary(Prefix + c);
}
pw = cw;
}
#if debugdisplay
DisplayOutCharStream();
DisplayDeCodeCodeStream();
#if debugdictionary
DisplayDeCodeDictionary();
#endif
#endif
}
#endregion
}
}
#undef debug
using System;
namespace LZW
{
class Class1
{
[STAThread]
static void Main(string[] args)
{
cLZW lzw = new cLZW();
#if debug
lzw.InCharStream = "ABBABABACCBBAAA";
#else
System.Console.WriteLine("Enter the Tests CharArray [a-zA-Z0-9]:");
lzw.InCharStream = System.Console.ReadLine();
#endif
System.Console.WriteLine("The Coding ... ...");
lzw.Coding();
System.Console.WriteLine("The DeCode ... ...");
lzw.SetDeCodeSCodetream(lzw.CodingCodeStream);
lzw.Decode();
System.Console.ReadLine();
}
}
}
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τ 认识你会不会是一种错误
如果这是个错误 也应该是个美丽的错误
但愿这个错误能够一辈子
______________ζ浮云￠惊龙