JAVAFX Write a program that enables the user to enter text and displays the Huff

Question

JAVAFX

Write a program that enables the user to enter text and displays the Huffman coding tree based on the text, as shown in Figure 25.25a. Display the weight of the subtree inside the subtree’s root circle. Display each leaf node’s character. Display the encoded bits for the text in a label. When the user clicks the Decode Text button, a bit string is decoded into text displayed in the label, as shown in Figure 25.25b.

Exercise25 17: Huffman Coding Animation Welcome Enter a text: Show Huffman Tree Fnter a hit string: Decode to Text 7.0 3.0 4.0 L.O 2.0 2.0 1.0 Exercise25 17: Huffman Coding Animation Enter a text: Show Huffman Tree Fnter a bit string: 00101110110111 Decode to Text Fnter a hit string: 0001001110110111 7.0 L.O 2.0 1.0 1.0 0001001110110111 is decoded to omleltc

Explanation / Answer

working java code for the same:

tree.java

public class Tree implements Comparable<Tree>{
   Node root;
  
public Tree(Tree t1, Tree t2) {
root = new Node();
root.left = t1.root;
root.right = t2.root;
root.frequency = t1.root.frequency + t2.root.frequency;
}
  
public Tree(String element, int frequency) {
root = new Node(element, frequency);
}
  
public int compareTo(Tree o) {
if (root.frequency < o.root.frequency)
return 1;
else if (root.frequency == o.root.frequency)
return 0;
else
return -1;
}
}

node.java:

public class Node {
   public Node(){};
   public Node(String chara, int freq){ character = chara; frequency = freq;}
   Node left, right = null;
   String character;
   int frequency;
   String code = "";
}

huffman.java

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

public class HuffmanCodingAnimation extends JApplet {
private static final long serialVersionUID = 1L;
private TreeView treeView = new TreeView();
private Tree tree;
  
public HuffmanCodingAnimation(Tree final_tree) {
   tree = final_tree;
add(new JScrollPane(treeView));
treeView.setTree(tree);
  
String[] codes = getCode(tree.root);
}
  
public String decode(String bits) {
String result = "";
  
Node p = tree.root;
for (int i = 0; i < bits.length(); i++) {
if (bits.charAt(i) == '0')
p = p.left;
else if (bits.charAt(i) == '1')
p = p.right;
else
return null;
  
if (p.left == null) {
result += p.character;
p = tree.root;
}
}
  
return result;
}
  
public static String encode(String text, String[] codes) {
String result = "";
for (int i = 0; i < text.length(); i++)
result += codes[text.charAt(i)];
return result;   
}
  
public static String[] getCode(Node root) {
if (root == null) return null;
String[] codes = new String[2 * 128];
assignCode(root, codes);
return codes;
}
  
private static void assignCode(Node root, String[] codes) {
if (root.left != null) {
root.left.code = root.code + "0";
assignCode(root.left, codes);
  
root.right.code = root.code + "1";
assignCode(root.right, codes);
}
else {
  
codes[(int)root.character.charAt(0)] = root.code;
}
}
  
class TreeView extends JPanel {   
   private static final long serialVersionUID = 1L;
   private int radius = 20; // Tree node radius
private int vGap = 50; // Gap between two levels in a tree
Tree tree;
  
public TreeView() {
}
  
public TreeView(Tree tree) {
this.tree = tree;
}
  
public void setTree(Tree tree) {
this.tree = tree;
repaint();
}
  
protected void paintComponent(Graphics g) {
super.paintComponent(g);

if (tree == null) return;
  
if (tree.root != null) {
// Display tree recursively
displayTree(g, tree.root, getWidth() / 2, 30,
getWidth() / 4);
}
}
  
private void displayTree(Graphics g, Node root,
int x, int y, int hGap) {
// Display the root
g.drawOval(x - radius, y - radius, 2 * radius, 2 * radius);
g.drawString(root.frequency + "", x - 6, y + 4);
  
if (root.left == null) // Display the character for leaf node
g.drawString(root.character + "", x - 6, y + 34);
  
if (root.left != null) {
// Draw a line to the left node
connectLeftChild(g, x - hGap, y + vGap, x, y);
// Draw the left subtree recursively
displayTree(g, root.left, x - hGap, y + vGap, hGap / 2);
}
  
if (root.right != null) {
// Draw a line to the right node
connectRightChild(g, x + hGap, y + vGap, x, y);
// Draw the right subtree recursively
displayTree(g, root.right, x + hGap, y + vGap, hGap / 2);
}
}
  
/** Connect a parent at (x2, y2) with
* its left child at (x1, y1) */
private void connectLeftChild(Graphics g,
int x1, int y1, int x2, int y2) {
double d = Math.sqrt(vGap * vGap + (x2 - x1) * (x2 - x1));
int x11 = (int)(x1 + radius * (x2 - x1) / d);
int y11 = (int)(y1 - radius * vGap / d);
int x21 = (int)(x2 - radius * (x2 - x1) / d);
int y21 = (int)(y2 + radius * vGap / d);
g.drawLine(x11, y11, x21, y21);
g.drawString("0", (x11 + x21) / 2 - 5, (y11 + y21) / 2);
}
  
/** Connect a parent at (x2, y2) with
* its right child at (x1, y1) */
private void connectRightChild(Graphics g,
int x1, int y1, int x2, int y2) {
double d = Math.sqrt(vGap * vGap + (x2 - x1) * (x2 - x1));
int x11 = (int)(x1 - radius * (x1 - x2) / d);
int y11 = (int)(y1 - radius * vGap / d);
int x21 = (int)(x2 + radius * (x1 - x2) / d);
int y21 = (int)(y2 + radius * vGap / d);
g.drawLine(x11, y11, x21, y21);
g.drawString("1", (x11 + x21) / 2 + 5, (y11 + y21) / 2);
}
  
public Dimension getPreferredSize() {
return new Dimension(300, 300);
}
}
}

Related Questions

Navigate

• Browse (All)
• Browse J
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.