private static bool TestBuildHuffmanCode(Dictionary<char, double> charFrequency, Dictionary<char, string> huffmanCodeCorrect)
{
bool testPassed = true;
HuffmanTree test = new HuffmanTree(charFrequency);
var huffmanCodeGenerated = test.dict;
string pool = "";
foreach (KeyValuePair<char, string> kvp in huffmanCodeCorrect)
{
pool += kvp.Key;
}
foreach (char s in pool)
{
Console.WriteLine(s + "\t" + huffmanCodeGenerated[s] + "\t==\t" + s + "\t" + huffmanCodeCorrect[s]);
if (huffmanCodeGenerated[s] != huffmanCodeCorrect[s])
testPassed = false;
}
if (testPassed)
Console.WriteLine("Test: Passed.\n");
else
Console.WriteLine("Test: Failed.");
return testPassed;
}
static void Main(string[] args)
{
if (args.Length < 1 || args[0] == string.Empty)
{
Console.WriteLine("Please specify an input parameter.");
return;
}
var orig = args[0];
var hf = new HuffmanTree()
.Build(orig);
var encoded = hf.Encode(orig);
var decoded = hf.Decode(encoded);
Console.WriteLine($"Original message: {orig}");
Console.WriteLine($"Encoded message: {encoded.ToBinaryString()}");
Console.WriteLine($"Decoded message: {decoded}");
hf.Root.Print();
}
static void importfromfileTest(string[] args)
{
Dictionary<char, int> zeichentabelle;
Dictionary<char, double> relativeAnzahl;
string file = args[0];
string text = "";
try
{
text = Dictcreator.getInput(file);
}
catch (Exception e)
{
Console.WriteLine(e.Message);
}
zeichentabelle = Dictcreator.createDictionaryFromString(text);
relativeAnzahl = Dictcreator.getRelativeFrequencyDict(zeichentabelle);
HuffmanTree tree = new HuffmanTree(relativeAnzahl);
tree.printTree(tree.root);
}
// this method creates a tree based on text
public static HuffmanTree CreateFromText(string text)
{
// the list that we wanna fill up with nodes
List <HuffmanNode> nodeList = new List <HuffmanNode>();
// all the characters from the text
char[] characters = text.ToCharArray();
// loop thought the characters
for (int i = 0; i < characters.Length; i++)
{
// the character as a string
string read = characters[i].ToString();
// has the node already been created?
if (nodeList.Exists(x => x.Symbol == read))
{
// If is yes, find the index of the Node and increase the frequency of the Node.
nodeList[nodeList.FindIndex(y => y.Symbol == read)].Frequency++;
}
else
{
// If is no, create a new node and add to the List of Nodes
nodeList.Add(new HuffmanNode(read));
}
}
// sort them, this is done based on frequency because of IComparable<HuffmanNode>.CompareTo
nodeList.Sort();
// loop thought them, until only one is left
while (nodeList.Count > 1)
{
// Get the node of the first index of List, this is the one with the lowest frequency
HuffmanNode node1 = nodeList[0];
// and delete it.
nodeList.RemoveAt(0);
// do the same thing again
HuffmanNode node2 = nodeList[0];
nodeList.RemoveAt(0);
// make a parant node with node1 and node2 and the left and right child nodes
nodeList.Add(new HuffmanNode(node1, node2));
// and sort it again according to frequency.
nodeList.Sort();
}
// create a tree based on the remaining root node
HuffmanTree tree = new HuffmanTree(nodeList[0]);
// this is a recursive function to set the binary code of every leaf node
void setCodeToTheTree(HuffmanNode Nodes, BitArray code = null)
{
// if the current code is not set, set it to an empty BitArray
if (code == null)
{
code = new BitArray(new bool[] { });
}
// if the code is empty do nothing
if (Nodes == null)
{
return;
}
// if there is no left node and right node, then set the code based on the current code
if (Nodes.LeftChildNode == null && Nodes.RightChildNode == null)
{
Nodes.Code = code;
return;
}
// create a bitlist for the left node
BitList left = BitList.Parse(code);
// add false for the left side
left.Add(false);
// call this function recursively, with the left bitlist and the left side node
setCodeToTheTree(Nodes.LeftChildNode, left.ToBitArray());
// create a bitlist for the right node
BitList right = BitList.Parse(code);
// add true for the right side
right.Add(true);
// call the function recursively, with the right bitlist and the right side node
setCodeToTheTree(Nodes.RightChildNode, right.ToBitArray());
}
// call the recursive function
setCodeToTheTree(tree.Root);
// the tree
return(tree);
}
static void Main(string[] args)
{
HuffmanTree.EncodingType = Encoding.UTF8;
List <Article> articles = new List <Article> {
new Article()
{
title = "den danske grundlov",
extract = SomeRandomText.DenDanskeGrundlov
},
new Article()
{
title = "mini srp infohæfte 2018",
extract = File.ReadAllText(@"E:\Libraries\Documents\Visual Studio 2017\Projects\huffman\huffman\MiniSRPinfohæfte2018.txt")
},
new Article()
{
title = "euklids elementer",
extract = File.ReadAllText(@"E:\Libraries\Documents\Visual Studio 2017\Projects\huffman\huffman\EuklidsElementer.txt")
}
};
if (Directory.Exists(OUTPUT_DIR))
{
Directory.Delete(OUTPUT_DIR, true);
}
var outputDir = Directory.CreateDirectory(OUTPUT_DIR);
foreach (var article in articles)
{
var tree = HuffmanTree.CreateFromText(article.extract);
var subDir = outputDir.CreateSubdirectory(article.title);
var treeFilePath = Path.Combine(subDir.FullName, "tree.json");
File.Create(treeFilePath).Close();
File.WriteAllText(treeFilePath, tree.JSONEncode());
var originalFilePath = Path.Combine(subDir.FullName, "original.txt");
File.Create(originalFilePath).Close();
File.WriteAllText(originalFilePath, article.extract);
var encodedFilePath = Path.Combine(subDir.FullName, "encoded.txt");
File.Create(encodedFilePath).Close();
var encodedData = tree.Encode(article.extract);
File.WriteAllBytes(encodedFilePath, encodedData);
var encodedReadAbleFilePath = Path.Combine(subDir.FullName, "encoded_readable.txt");
File.Create(encodedReadAbleFilePath).Close();
File.WriteAllText(encodedReadAbleFilePath, (new BitArray(encodedData)).Print());
var decodedFilePath = Path.Combine(subDir.FullName, "decoded.txt");
File.Create(decodedFilePath).Close();
var decodedData = tree.Decode(encodedData);
File.WriteAllText(decodedFilePath, decodedData);
var statsFilePath = Path.Combine(subDir.FullName, "stats.txt");
File.Create(statsFilePath).Close();
File.WriteAllLines(statsFilePath, new string[] {
"original size: " + (article.extract.Length * 8) + " b",
"compressed size: " + encodedData.Length + " b",
"compression percentage: " + (100 * ((double)encodedData.Length / ((double)HuffmanTree.EncodingType.GetBytes(article.extract).Length))) + "%",
"tree size as json: " + (HuffmanTree.EncodingType.GetBytes(tree.JSONEncode()).Length) + " b",
"tree size as bytes: " + (new Func <string>(() => {
byte[] bytes;
IFormatter formatter = new BinaryFormatter();
using (MemoryStream stream = new MemoryStream()){
formatter.Serialize(stream, tree);
bytes = stream.ToArray();
}
return("" + bytes.Length);
}))() + " b",
"lossness: " + (article.extract == decodedData ? "yes" : (new Func <string>(() => {
string re = "no" + Environment.NewLine;
if (article.extract.Length == decodedData.Length)
{
List <string> errors = new List <string>();
for (int i = 0; i < article.extract.Length; i++)
{
if (article.extract[i] != decodedData[i])
{
errors.Add("position " + i + " does not match; original: " + article.extract[i].ToString() + ", decoded: " + decodedData[i].ToString());
}
}
re += String.Join(Environment.NewLine, errors.ToArray());
}
else
{
re += "not the same length; original: " + article.extract.Length + ", decoded: " + decodedData.Length;
}
return(re);
}))())
});
}
Console.WriteLine("Done");
Thread.Sleep(-1);
}
// this method creates a tree based on text
// Denne funktion laver et træ baseret på tekst
public static HuffmanTree CreateFromText(string text)
{
// the list that we wanna fill up with nodes
// Listen der skal fyldes med noder
List <HuffmanNode> nodeList = new List <HuffmanNode>();
// all the characters from the text
// Alle symbolerne fra teksten
char[] characters = text.ToCharArray();
// loop thought the characters
// Gentag igennem symbolerne
for (int i = 0; i < characters.Length; i++)
{
// the character as a string
// Symbolerne som strenge
string read = characters[i].ToString();
// has the node already been created?
// Er noden allerede blevet skabt?
if (nodeList.Exists(x => x.Symbol == read))
{
// If is yes, find the index of the Node and increase the frequency of the Node.
// Hvis ja, find indekset for noden og øg frekvensen for node
nodeList[nodeList.FindIndex(y => y.Symbol == read)].Frequency++;
}
else
{
// If is no, create a new node and add to the List of Nodes
// Hvis nej, skab en ny node og tilføj den til listen over node
nodeList.Add(new HuffmanNode(read));
}
}
// sort them, this is done based on frequency because of IComparable<HuffmanNode>.CompareTo
// Sorter dem, dette gøres baseret på frekvens fordi at IComparable<HuffmanNode>.CompareTo
nodeList.Sort();
// loop thought them, until only one is left
// Kør igennem dem alle sammen indtil der kun er en tilbage
while (nodeList.Count > 1)
{
// Get the node of the first index of List, this is the one with the lowest frequency
// Få noden for det første indeks af Listen, dette er den med den laveste frekvens
HuffmanNode node1 = nodeList[0];
// and delete it.
// Fjern den
nodeList.RemoveAt(0);
// do the same thing again
// Gør det samme igen
HuffmanNode node2 = nodeList[0];
nodeList.RemoveAt(0);
// make a parant node with node1 and node2 and the left and right child nodes
// Lav en parent-node med node1 og node1 og de venstre og højre child-noder
nodeList.Add(new HuffmanNode(node1, node2));
// and sort it again according to frequency.
// Og sorter det igen efter frekvens
nodeList.Sort();
}
// create a tree based on the remaining root node
// Lav et træ baseret på den tilbageværende rod-node
HuffmanTree tree = new HuffmanTree(nodeList[0]);
// this is a recursive function to set the binary code of every leaf node
// Dette er en rekursiv funktion for at sætte den binære værdi for hvert blad
void setCodeToTheTree(HuffmanNode Nodes, BitArray code = null)
{
// if the current code is not set, set it to an empty BitArray
// Hvis den nuværende kode ikke er sat, sættes den til et tomt BitArray
if (code == null)
{
code = new BitArray(new bool[] { });
}
// if the code is empty do nothing
// Hvis koden er tom, gør intet
if (Nodes == null)
{
return;
}
// if there is no left node and right node, then set the code based on the current code
// Hvis der ikke er nogen venstre node, sæt koden baseret på den nuværende kode
if (Nodes.LeftChildNode == null && Nodes.RightChildNode == null)
{
Nodes.Code = code;
return;
}
// create a bitlist for the left node
// lav en bitliste for den venstre node
BitList left = BitList.Parse(code);
// add false for the left side
// tilføj false for den venstre side
left.Add(false);
// call this function recursively, with the left bitlist and the left side node
// Kald denne funktion rekursivt, med den venstre bitliste og den venstre node
setCodeToTheTree(Nodes.LeftChildNode, left.ToBitArray());
// create a bitlist for the right node
// Lav en bitliste for den højre node
BitList right = BitList.Parse(code);
// add true for the right side
// tilføj true for den højre side
right.Add(true);
// call the function recursively, with the right bitlist and the right side node
// Kald denne funktion rekursivt, med den højre bitliste og den højre node
setCodeToTheTree(Nodes.RightChildNode, right.ToBitArray());
}
// call the recursive function
// Kald den rekursive funktion
setCodeToTheTree(tree.Root);
// the tree
// Træet returneres
return(tree);
}
