//entering values in map inside nodes and arranging those nodes in Priority queue with smallest frequencies in front
PQueue.PriorityQueue nodesinQueue(Dictionary <char, int> Dic)
{
PQueue.cNode node = new PQueue.cNode(); //node created
PQueue.PriorityQueue pQueue = new PQueue.PriorityQueue(); //queue created
foreach (KeyValuePair <char, int> kvp in Dic) //reading from frequency dictionary
{
node.value = kvp.Key;
node.frequency = kvp.Value; //setting the values of node
pQueue.insertWithPriority(node); //entering the node
node = new PQueue.cNode();
}
return(pQueue);
}
//writing tree at the top of decoding file
void Write_tree(PQueue.cNode r)
{
if (r.leftZero == null && r.rightOne == null)
{
treeFile.Write("0");
treeFile.Write(r.value);
}
else
{
treeFile.Write("1");
Write_tree(r.leftZero);
Write_tree(r.rightOne);
}
}
static void Main(string[] args)
{
Program myComp = new Program(); //creating instance of the main file
//string S; //Enter string to find the huffman code
//S = Console.ReadLine();
// Console.WriteLine("String Entered: " + S);
Console.WriteLine("Enter File Name: ");
var fileName = Console.ReadLine();
Console.WriteLine(fileName);
Dictionary <char, int> Dic = new Dictionary <char, int>();
Dic = myComp.frequency(fileName); //frequency calculated
myComp.printMap(Dic);
//entering data in nodes then storing them in queue
PQueue.PriorityQueue pQueue = new PQueue.PriorityQueue();
pQueue = myComp.nodesinQueue(Dic);
//creating encooding tree
myComp.root = myComp.HuffmanEncoding(pQueue);
PQueue.cNode top = myComp.root; //temporary storing the value
Console.WriteLine(top.getValue());
myComp.HuffCode(top, "");
myComp.printCodes(myComp.HuffmanCode);
//writing tree in file
// top = myComp.root; //temporary storing the value
//myComp.EncodingTreeWrite(top);
//compressing file
FileStream fs = File.OpenRead(fileName);
myComp.WriteCompressFile(fs);
Console.ReadKey();
}
//building the tree
PQueue.cNode HuffmanEncoding(PQueue.PriorityQueue pQueue)
{
int n = pQueue.count;
while (n != 1)
{
PQueue.cNode node = new PQueue.cNode();
node.leftZero = pQueue.remove();
node.rightOne = pQueue.remove();
node.frequency = node.leftZero.frequency + node.rightOne.frequency;
node.value = 'a';
pQueue.insertWithPriority(node);
pQueue.print();
Console.WriteLine("Inserted");
n = pQueue.count;
}
return(pQueue.Top());
}
public void printPreorder(PQueue.cNode node)
{
if (node == null)
{
return;
}
/* first print data of node */
if (node.leftZero == null && node.rightOne == null)
{
Console.Write(node.value + " ");
}
/* then recur on left sutree */
printPreorder(node.leftZero);
/* now recur on right subtree */
printPreorder(node.rightOne);
}
//decompress the file
public void decompress(string fileName, FileStream fs2)
{
readBitByBit bit = new readBitByBit(fileName);
FileTreeroot = ReadTreeHeader(bit);
Console.WriteLine("insode decompress");
program.printPreorder(FileTreeroot);
var output = new StreamWriter(fs2);
int returnbit = -1;
char leaf = '1'; //checking if we reached the end of file
// PQueue.cNode top = root;
PQueue.cNode top = FileTreeroot;
while (true) //will run until we found the pseduo_EOF
{
if (top.leftZero == null && top.rightOne == null) //if leaf node is reached
{
leaf = top.value;
if (leaf == (char)program.Pseudo_EOF) //if it is last letter close the file
{
output.Close();
break;
}
else
{
output.Write(leaf); //else write in file
top = FileTreeroot; //again start from root
}
}
returnbit = bit.bitRead();
if (returnbit == 0) //if not leaf keep on reading the file
{
top = top.leftZero;
}
else if (returnbit == 1)
{
top = top.rightOne;
}
}
output.Close();
bit.close();
}
//decompress the file
public PQueue.cNode ReadTreeHeader(readBitByBit bit)
{
char c = bit.();
PQueue.cNode node = new PQueue.cNode();
if (c == '1')
{
Console.WriteLine("inside 1 : ");
node = new PQueue.cNode();
node.value = bit.ByteRead();
Console.WriteLine("inside 1 value: " + node.value);
return node;
}
else
{
Console.WriteLine("inside 0");
PQueue.cNode leftChild = ReadTreeHeader(bit);
PQueue.cNode rightChild = ReadTreeHeader(bit);
node = new PQueue.cNode('0', leftChild, rightChild);
return node;
}
}
void HuffCode(PQueue.cNode root, string str)
{
if (root == null) //base case
{
return;
}
if (root.leftZero == null && root.rightOne == null) //if we reached at leaf node
{
try
{
HuffmanCode.Add(root.value, str); //if it is not already in the Dictionary
}
catch
{
HuffmanCode[root.value] = str; //if it is in the dictionary just edit 2nd value
}
}
else
{
HuffCode(root.leftZero, str + "0"); //concatination to form the code
HuffCode(root.rightOne, str + "1");
}
}
//Writng decoding tree
void EncodingTreeWrite(PQueue.cNode r)
{
string fileName = "tree.cmu";
try
{
// Check if file already exists. If yes, delete it.
if (File.Exists(fileName))
{
File.Delete(fileName);
}
// Create a new file
treeFile = new StreamWriter(fileName, true, Encoding.ASCII);
Write_tree(r);
treeFile.Write(254);
treeFile.Close();
}
catch (Exception Ex)
{
Console.WriteLine(Ex.ToString());
}
}