ACM Jett, Duke Workshop II

Agenda

Morning I

2003 AP exam questions in Java

Morning II

1. Modify method standardCount so that it calculates how many 1-letter words, 2-letter words, ... 15-letter words there are. Print a table of occurrences, similar to the table printed in DiceAnalyzer.java programmer.

   You'll need to create an array as an instance field/data member, initialize it, update the counts in method standardCount and then add a new method (and call it) to print the contents of the array. Test the program using data/poe.txt and data/hamlet.txt.

2. Use an ArrayList to store all the words read from a file, but don't store a word if it's already in the list. You'll find the ArrayList method indexOf very helpful, see the API (via JCreator). Don't print the contents of the ArrayList when done, but do print (using a method reportStats) the number of words stored. Test the program using data/poe.txt and data/hamlet.txt.

3. Modify the program so that instead of using an ArrayList, it uses a TreeSet (also from java.util). You'll need to use just the four statements below, but you'll need to put them in the proper location. See how much longer/shorter your program takes to run than when using the ArrayList version.

      TreeSet mySet;
   
      mySet = new TreeSet();
   
      mySet.add(word);
   
      System.out.println("# unique words = " + mySet.size());
   

Afternoon I

1. Currently if a URL doesn't begin with http:// the browser won't load a page correctly. Fix the program so that if a user-entered URL doesn't begin witht he proper prefix, then it is added to the URL before loading.

2. The back/next buttons don't work. Design a solution so that these buttons will work as you expect them to. Implement the solution.

   (hint: One simple idea is to use an ArrayList of URLs that have been visited and a current index into this list. Going back/next decrements or increments, respectively, the index.)

3. Enable/Disable the buttons and menu items appropriately depending on whether there is a next or back page to visit.

Afternoon II

Copy the files to a new folder, then modify only the model so that a game of light-out is played. We'll demo lights out so you can see how it works.