Final Exam Review Fall2006

1. If you don't post, neither will we. We will not be posting official solutions to these problems at all! If one of you gets it right, terrific!
2. We will try to always point out if an answer is wrong. We won't always point out when the answer is right.
3. We are glad to work with you toward the right answer. We will give hints, and I'm glad to respond to partial guesses.

True or False

Short answer

Understanding Java modifiers

Understanding UML

Understanding inheritance

public class Superhero {
  public String name;
  public int strength;
  public Superhero() {
    name = “Batman”;
    strength = 10;
  }
  public void introduce() {
    System.out.print(“Hello.  I am “ + name + “.  And “);
    if(strength < 15) {
      System.out.println(“I am weak.”);
    } else {
      System.out.println(“I am strong.”);
    }
}


public class  NinjaTurtle extends Superhero {
  public NinjaTurtle(int i) {
    super();
    String[] turtles = {“Leonardo”, “Donatello”, “Raphael”, “Michaelangelo”};

    name = turtles[i];
    strength = 25;
  }
  public void introduce() {
    System.out.println(“I’m “ + name);
  }
}

• LLNode is an abstract class that implements all of the basic functionality of a linked list.
• DrawableNode is a class that knows how to draw itself and also has linked list functionality.

abstract public class LLNode {

  /*The next branch/node/whatever to process*/
  public LLNode next;

  /*Constructor for LLNode just sets next to null*/
  public LLNode() {
    next = null;
  }

  /**
   *Methods to set and get next elements* @param nextOne next element in list
   */
  public void setNext(LLNode nextOne) {
    this.next = nextOne;
  }

  public LLNode getNext() {
    return this.next;
  }

  /*** Method to remove node from list, fixing links
   *appropriately* @param node element to remove from list.
   */
  public void remove(LLNode node) {
    /* assume you have working code here */
  }

  /*** Insert the input node after this node
   *@param node element to insert after this
   **/
  public void insertAfter(LLNode node) {
    /* assume you have working code here */
  }
} //end of LLNode class

public class DrawableNode {
  public DrawableNode next;

  /* Constructors */
  public DrawableNode() {
    next = null;
  }

  /* Methods */
  public void setNext(DrawableNode nextOne) {
    this.next = nextOne;
  }

  public Drawable getNext() {
    Return this.next;
  }

  public void remove(DrawableNode node) {
    /* Assume working code */

  public void insertAfter(DrawableNode node) {
    /* Assume working code */
  }
}// end of DrawableNode class

GUIs are trees

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

/** Simple GUI Tree Example
  * This is a GUI Tree Example designed to give you an idea
  * of what we want you to do on the exam. We realize that
  * there is not much material on this in the lecture slides, 
  * but a GUI Tree is very similar to the work you have done
  * with "Sound Trees" (i.e. SoundBranch, etc) 
  **/
public class SimpleGUITreeExample extends JPanel{
  
  public SimpleGUITreeExample(){
    /** Since our class extends JPanel, it itself (this) is a 
      * JPanel as well. So let's set the layout to be a 
      * BorderLayout
      **/
    this.setLayout(new BorderLayout());
    
    /** Let's start creating the panel to add into this
      */
    
    //panel1 is a JPanel with a BorderLayout
    JPanel panel1 = new JPanel();
    panel1.setLayout(new BorderLayout());
    
    //Here we create button1, button2, button3 which are all JButtons
    JButton button1 = new JButton("Button 1");
    JButton button2 = new JButton("Button 2");
    JButton button3 = new JButton("Button 3");
    
    //We add button1, button2, button3 to panel1
    panel1.add(button1, BorderLayout.NORTH);
    panel1.add(button2, BorderLayout.CENTER);
    panel1.add(button3, BorderLayout.SOUTH);
    
    //Add panel1 to this
    this.add(panel1, BorderLayout.NORTH);
    
    //panel2 is a JPanel with a FlowLayout
    JPanel panel2 = new JPanel();
    panel2.setLayout(new FlowLayout());
    
    //We create button4 and button5 which are JButtons
    JButton button4 = new JButton("Button 4");
    JButton button5 = new JButton("Button 5");
    
    //Add button4 and button5 to panel2
    panel2.add (button4);
    panel2.add (button5);
    
    //Add panel2 to this
    this.add(panel2, BorderLayout.SOUTH);
    
  }
    public static void main (String[] args){
    JFrame frame = new JFrame ("Simple GUI Tree Example");
    frame.setDefaultCloseOperation (JFrame.EXIT_ON_CLOSE);
    
    SimpleGUITreeExample tree = new SimpleGUITreeExample();
    frame.getContentPane().add(tree);
    frame.pack();
    frame.setVisible(true);
  }  
}

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

public class ExampleGUI extends JPanel {

  public ExampleGUI() {

    JPanel buttonPanel = new JPanel();
    JPanel contentPanel = new JPanel();
    contentPanel.setLayout(new BorderLayout());
    JPanel toSendTextPanel = new JPanel();
    toSendTextPanel.setLayout(new BorderLayout());
    
    JLabel receivedTextLabel = new JLabel("Received Messages");
    JLabel toSendTextLabel = new JLabel("Text to Send");
    JTextArea receivedText = new JTextArea("Jess: Hey Dawn, are you TAing next semester?\n"+
                                           "Dawn: Nope. I'll be in sunny California getting a tan.\n"+
                                           "Jess: Okay, but you have to get rid of that ugly farmer's tan.", 10, 10);
    JTextArea toSendText = new JTextArea("Start typing here", 5, 10);
 
    JButton warn = new JButton("Warn");
    JButton chat = new JButton("Chat");
    JButton send = new JButton("Send");
    
    this.setLayout(new BorderLayout());

    toSendTextPanel.add(toSendTextLabel, BorderLayout.NORTH);
    toSendTextPanel.add(toSendText, BorderLayout.SOUTH);
    
    buttonPanel.add(warn);
    buttonPanel.add(chat);
    buttonPanel.add(send);

    contentPanel.add(receivedTextLabel, BorderLayout.NORTH);
    contentPanel.add(receivedText, BorderLayout.CENTER);
    contentPanel.add(toSendTextPanel, BorderLayout.SOUTH);

    add(contentPanel, BorderLayout.CENTER);
    add(buttonPanel, BorderLayout.SOUTH);
  }

  public static void main(String[] args) {
    JFrame frame = new JFrame("IM");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    
    ExampleGUI ex_gui = new ExampleGUI();
    frame.getContentPane().add(ex_gui);
    frame.pack();
    frame.setVisible(true);
  }
}

Writing methods on the Picture class

The following is the clearBlue() method of the class Picture.
/*** Method to clear the blue from the picture (set
 *the blue to 0 for all pixels*/
public void clearBlue()
{
  Pixel[] pixels = this.getPixels();
  Pixel pixel = null;
  int index = 0;

  while(index < pixels.length)
  {
    pixel = pixels[index];
    pixel.setBlue(0);
    index++;
  }
}

Public void vertical_stripes()
{

}

Insertion sort

Public void sort() {

  SimEvent considered = null;
  SimEvent compareEvent = null; //Just for use in the loop

  /*  Small index we’re comparing to */
  int compare;

  for(int position = 1;position < elements.size();position++){
    considered = (SimEvent) elements.get(position);
    
    compare = position;

    compareEvent = (SimEvent) elements.get(compare-1);
    while(compareEvent.getTime() > considered.getTime()) {
      elements.set(compare, elements.get(compare-1));
      compare = compare – 1;
      // If we get to the end of the array, stop
      if(compare <= 0) {break;}
      // else we get ready for the next time through the loop
      else { compareEvent = (SimEvent)elements.get(compare-1);}
    }

    elements.set(compare, considered);
  }// for all positions 1 to the end
}// end sort()

1. Why do we need two loops for this sorting algorithm? Explain the purpose of each.
2. How would we go about reversing the sort (lets say we wanted the most time consuming element to happen first)?
3. Why did we start out with the variable position being set to 1 instead of 0?
4. At the point in the code where considered is defined in the for loop, what do we know is true about the times of the SimEvents in the linked list that occur before the newly defined considered SimEvent?

Writing linked list methods

public void remove(LLNode node) {
  if(node == this) {
    System.out.println(“I can’t remove the first node”);
    return;
  }
  
  LLNode current = this;
  while(current.getNext() != null)
  {
    if(current.getNext() == node) {
      current.setNext(node.getNext());
      node.setNext(null);
      return (null);
    }
    current = current.getNext();
  }
}

Abstract Data Types

1. What operations can be performed on the stack abstract data type?
2. How is a stack different from a queue?

Simulations

Links to this Page

• Exam Reviews last edited on 4 December 2007 at 9:14 pm by c-76-17-114-206.hsd1.ga.comcast.net
• Final exam review Fall2006: True or False last edited on 13 December 2006 at 4:36 pm by r54h53.res.gatech.edu
• Final exam review Fall2006: Short answer last edited on 13 December 2006 at 4:36 pm by r54h53.res.gatech.edu
• Final exam review Fall2006: Understanding Java modifiers last edited on 13 December 2006 at 4:36 pm by r54h53.res.gatech.edu
• Final exam review Fall2006:Understanding UML last edited on 13 December 2006 at 4:37 pm by r54h53.res.gatech.edu
• Final exam review Fall2006:Understanding inheritance last edited on 13 December 2006 at 4:37 pm by r54h53.res.gatech.edu
• Final exam review Fall2006:GUIs are trees last edited on 14 December 2006 at 8:02 pm by lawn-128-61-124-35.lawn.gatech.edu
• Final exam review Fall2006:Writing methods on the Picture class last edited on 13 December 2006 at 4:39 pm by r54h53.res.gatech.edu
• Final exam review Fall2006:Insertion sort last edited on 13 December 2006 at 4:38 pm by r54h53.res.gatech.edu
• Final exam review Fall2006:Writing linked list methods last edited on 13 December 2006 at 9:27 pm by c-71-59-4-21.hsd1.ga.comcast.net
• Final exam review Fall2006:Abstract Data Types last edited on 13 December 2006 at 6:32 pm by lawn-128-61-114-26.lawn.gatech.edu
• Final exam review Fall2006:Simulations last edited on 13 December 2006 at 4:38 pm by r54h53.res.gatech.edu