/**
* Main method.
*
* @param args
* @throws IOException
*/
public static void main(String[] args) throws IOException {
Scanner scanner = new Scanner(System.in);
String newInput = " ";
File f = null;
boolean loopForFileName = true;
boolean loopForFileLocation = true;
// Looping to get correct input
while (loopForFileLocation == true) {
while (loopForFileName == true) {
System.out.print("Please enter a filename: ");
newInput = scanner.nextLine();
if (newInput.length() == 0) {
System.out.println("");
System.out.println("You must enter a file name. ");
System.out.println("");
} else {
loopForFileName = false;
}
}
File file = new File(newInput);
if (file.exists() == false) {
System.out.println("");
System.out.println("The file you entered was not found.");
System.out.println("");
loopForFileName = true;
} else {
loopForFileLocation = false;
f = file;
}
}
scanner.close();
System.out.println("");
// Character is the Key and Symbol is the Value
HashMap<Character, Symbol> Letters = new HashMap<Character, Symbol>();
String line;
BufferedReader reader = new BufferedReader(new FileReader(f));
// Reading data and putting it into the HashMap
while ((line = reader.readLine()) != null) {
for (int i = 0; i < line.length(); i++) {
char c = line.charAt(i);
Symbol s = Letters.get(c);
if (s == null) {
s = new Symbol(c, 0);
Letters.put(c, s);
}
s.addToFrequency();
}
}
reader.close();
ArrayHeap<Node> arrayHeap = new ArrayHeap<Node>();
// Adding to the ArrayHeap of Nodes
for (Symbol s : Letters.values()) {
Node n = new Node();
n.addSymbols(s);
arrayHeap.add(n);
}
ArrayHeap<Node> arrayOfNodes = arrayHeap;
Node results = new Node();
int counter = 0;
// Calculating code words using Nodes
while (arrayOfNodes.isEmpty() == false) {
Node rightNode = arrayOfNodes.removeMin();
if (arrayOfNodes.isEmpty()) {
if (counter == 0) {
rightNode.createNewCodeWord("1");
}
results = rightNode;
} else {
Node leftNode = arrayOfNodes.removeMin();
rightNode.createNewCodeWord("0");
leftNode.createNewCodeWord("1");
leftNode.addNode(rightNode);
arrayOfNodes.add(leftNode);
}
counter++;
}
// Displaying output
System.out.println("Variable Length Code Output");
System.out.println("____________________________________________________");
for (Symbol s : results.getSymbols()) {
System.out.printf(
"Symbol: %3s Codeword: %10s Frequency: %5d",
s.getCharacter(), s.getCodeWord(), s.getFrequency());
System.out.print("\n");
}
System.out.println("");
System.out.println(
"Average VLC codeword length: "
+ String.format("%.2f", results.getAvgVlcLength())
+ " bits per symbol");
System.out.println(
"Average Fixed length codeword length: "
+ String.format("%.2f", results.getAvgFixedLength())
+ " bits per symbol");
System.out.println("");
}
