Homework 6: Filling Boxes

CS 110 Introduction to Computing

Project #6: Filling Boxes

In this project you will be writing another "event driven" applet. The goal of this applet is to use arrays for the first time. The task is relatively simple, put a number of empty boxes onto an applet, then -- on hitting a button, pick random box to fill. Hit the button again to pick (randomly) another box to fill. Continue hitting the button until every box is filled. The interface should show whether or not each box is filled and how many times the just picked box has been filled. Also, the interface should say whether or not every box has been filled.

For my implementation, I chose to have one button and two labels. The button named "fill'rup", simply causes a box to be randomly picked for filling. If he box has already been filled, so be it. One of the labels, the upper one in the images below, shows the number of times the currently selected box has been filled. The other label simply says "More filling needed" or "every box filled" depending on whether or not every box is filled.

Boxes can be made by simply dividing the applet into a grid using vertical lines (as shown in the leftmost image). You might look at you homework 4 to remember how to do this. Then, when a box is filled change the color of the box to something other than white. (I use a randomly selected color.)

Your applet should have 6 boxes.

Here are some example images from my reference implementation.

Before any boxes have been filled
After a few boxes have been filled.
After every box has been filled.

When everything is working, count the number of button clicks needed to fill one box, then 2 boxes, then 3 boxes, ... Repeat this several times then draw a graph of the average number of button hits needed to fill each number of boxes. Finally, write less than one page explaining why it takes far more than 6 button hits to fill all 6 boxes. Your explanation might go on to speculate about filling up 10 boxes or 100 boxes using this approach. For example, suppose it took, on average 30 clicks to fill the 6 boxes (NOTE: 30 is definitely wrong so do not report this as your answer). Would you expect it would take 50 clicks to fill 10 boxes (you could do this experiment), or more or less. Would it take 500 clicks to fill 100 boxes? (You could also do this experiment, but it might get pretty boring.)

Due Date: November 9, at the beginning of class.
Submit:

A printout of the code for your applet. (See instructions on the class website for getting a good looking printout)
One printout of the applet with between 1 and 4 boxes filled.
The URL of the HTML page containing your applet
Less than 1 page containing the following:
- the graph described above (a hand drawn graph would be fine).
- Answers to the question asked above.

Grading:	Applet	90 pts
Grading:	Analysis	10 pts

Notes

Recall that you can obtain the size of an applet by putting the following into your paint method:

int appX = (int) getSize().getWidth();
int appY = (int) getSize().getHeight();

Extra Credit

5 points	Rather than simply filling your boxes with a block of color, fill them with something more interesting. For example, fill the boxes with a cardioid as we drew in class just after break.
5 points	If you do the first extra credit, use fillPolygon to create a cardioid that is full of color.
5 points	Make the box show the number of times it has been filled. For example, you might make the box into a sort of bar chart, where the height of the color in the box is dependent on the number of times it has been filled.

geoffrey

Last modified: Mon Nov 1 19:25:45 EST 2004