clzw.cs

LZW压缩

#undef debug
#define debugdisplay
#undef debugdictionary
using System;
using System.Collections;

namespace LZW
{
    public class cLZW
    {
        private String _InCharStream;


        public cLZW()
        {
        }

        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();
          
            for (int i = 0; i < 256; i++)
            {
                _CodingDictionary.Add((char)i);
            }

        }
        
        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 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
            DisplayCodingDictionary();

        }



        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();
            for (int i = 0; i < 256; i++)
            {
                _DeCodeDictionary.Add((char)i);
            }
        }
        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;
            }
        }

    }
}






//namespace LZW
//{
//    class Class1
//    {
//        [STAThread]
//        static void Main(string[] args)
//        {
            

//            //cLZW lzw = new cLZW();
//            //System.Console.WriteLine("Enter the Tests CharArray [a-zA-Z0-9]:");
//            //lzw.InCharStream = System.Console.ReadLine();

//            //System.Console.WriteLine("The Coding  ");
//            //lzw.Coding();
//            //System.Console.WriteLine("The DeCode  ");
//            //lzw.SetDeCodeSCodetream(lzw.CodingCodeStream);
//            //lzw.Decode();
//            //System.Console.ReadLine();
//        }
//    }
//}