public void inOrder(BinaryTreeNode <CharacterFrequency> p, string encoding)
{
if (p != null)
{
if (p.Left != null)
{
inOrder(p.Left, encoding + "0");
}
if (p.Right != null)
{
inOrder(p.Right, encoding + "1");
}
if (p.isLeaf())
{
if (encodingTable == null)
{
encodingTable = new LinkedList <EncodingData>();
}
encodingTable.AddLast(new EncodingData((byte)p.Data.Ch, encoding));
}
}
}
static void Main(string[] args)
{
//class variables
#region Variables
StreamReader txtIn;
StreamWriter txtOut = new StreamWriter(String.Format("encoding{0}", args[1]));
byte b = 0;
int pow = 7;
char ch;
string encoding;
string line;
char delimiter = '»';
#endregion
//check for proper usage
#region Proper Usage
if (args.Length != 2)
{
Console.WriteLine("Proper usage is: program.exe inFile outFile");
Console.ReadKey();
return;
}
//
try
{
txtIn = new StreamReader(args[0]);
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
Console.ReadLine();
return;
}
#endregion
//read the file and count the character frequencies
#region List of Character Frequencies
LinkedList <CharacterFrequency> list = new LinkedList <CharacterFrequency>();
char c = (char)txtIn.Read();
while (!txtIn.EndOfStream)
{
findFrequency(c, list);
c = (char)txtIn.Read();
}
findFrequency(c, list);
txtIn.Close();
#endregion
//create a sorted linked list of binary tree nodes
#region Sorted List of binary Tree Nodes of Character Frequencies
SortedLinkedList <BinaryTreeNode <CharacterFrequency> > sll = new SortedLinkedList <BinaryTreeNode <CharacterFrequency> >();
foreach (CharacterFrequency charf in list)
{
sll.Add(new BinaryTreeNode <CharacterFrequency>(charf, charf.Frequency));
}
#endregion
//while the list is not empty, build the binary tree nodes, adding the two smallest values
#region Building the Tree
while (sll.Count > 1)
{
BinaryTreeNode <CharacterFrequency> left;
BinaryTreeNode <CharacterFrequency> right;
BinaryTreeNode <CharacterFrequency> phNode;
left = sll.First.Value;
sll.RemoveFirst();
right = sll.First.Value;
sll.RemoveFirst();
phNode = new BinaryTreeNode <CharacterFrequency>(null, (left.Value + right.Value));
phNode.Left = left;
phNode.Right = right;
sll.Add(phNode);
}
BinaryTree tree = new BinaryTree(sll.First.Value);
tree.inOrder(tree.Root, "");
//write the encoding table to a new file
foreach (EncodingData d in tree.EncodingTable)
{
txtOut.WriteLine(String.Format("{0}", d.ToString()));
}
#endregion
//compress the file
#region Compression
txtIn = new StreamReader(args[0]);
StreamWriter compressedFile = new StreamWriter(args[1]);
while (!txtIn.EndOfStream)
{
ch = (char)txtIn.Read();
encoding = findEncoding(ch, tree.EncodingTable);
foreach (char character in encoding)
{
if (character == '1')
{
b = (byte)(b | (byte)Math.Pow(2, pow));
}
pow--;
if (pow < 0)
{
pow = 7;
compressedFile.Write((char)b);
b = 0;
}
}
}
if (pow != 7)
{
compressedFile.Write((char)b);
}
txtOut.Close();
txtIn.Close();
compressedFile.Close();
#endregion
//decompress the file
#region Decompression
txtIn = new StreamReader(String.Format("encoding{0}", args[1]));
//decompression
BinaryTree charTree = new BinaryTree(new BinaryTreeNode <CharacterFrequency>(new CharacterFrequency((char)0, 0), 0));
BinaryTreeNode <CharacterFrequency> node = charTree.Root;
while (!txtIn.EndOfStream)
{
line = txtIn.ReadLine();
string[] holder;
holder = line.Split(delimiter);
if (holder.Length > 1)
{
foreach (char letter2 in holder[1])
{
if (letter2 == '0')
{
if (node.Left == null)
{
node.Left = new BinaryTreeNode <CharacterFrequency>(new CharacterFrequency((char)0, 0), 0);
}
node = node.Left;
}
else
{
if (node.Right == null)
{
node.Right = new BinaryTreeNode <CharacterFrequency>(new CharacterFrequency((char)0, 0), 0);
}
node = node.Right;
}
}
byte holdingByte = 0;
Byte.TryParse(holder[0], out holdingByte);
node.Data.Ch = (char)holdingByte;
node = charTree.Root;
}
}
txtIn.Close();
txtIn = new StreamReader(args[1]);
StreamWriter decompressedFile = new StreamWriter(String.Format("decompressed{0}", args[0]));
byte decomp;
byte decompVar;
pow = 7;
node = charTree.Root;
while (!txtIn.EndOfStream)
{
decomp = (byte)txtIn.Read();
while (pow >= 0)
{
decompVar = (byte)(decomp & (byte)(Math.Pow(2, pow)));
if (decompVar > 0)
{
//if the variable is greater than 0, go to the right
node = node.Right;
}
else
{
node = node.Left;
}
if (node.isLeaf())
{
decompressedFile.Write(node.Data);
node = charTree.Root;
}
pow--;
}
pow = 7;
}
decompressedFile.Close();
txtIn.Close();
txtOut.Close();
#endregion
Console.ReadKey();
}
