CS 206 - Introduction to Data Structures

Homework 3

ArrayList - Zipcode lookup

Due Thursday, Feb 13 prior to 11:59PM

Overview

Input File Format

We will only use three of these fields, the zipcode (#1), the latitude (#6) and the longitude (#7). In the sample line, that is 07677 (in quotes), 41.02 and -74.05.

As in the last assignment, some lines are missing some information, but all lines have the correct number of commas (11).

The following little java program shows how to remove quotation marks from a string

    public class A {
    public static void main(String[] args) {
	    String s = "\"This is a test\"";
            System.out.println(s);
            String sr = s.replace("\"", "");
            System.out.println(sr);
    }}
    

Design

Specific Tasks

• In visual Studio code close your current folder and create / open a new one. I assume below that you named the folder Assignment3 but the name is really up to you.
• Copy all of your files from Assignment 2 in the Assignment3 folder. You can use the UNIX cp commmand for this task (as in lab 3). The following directions make lots of assumptions about your directories. But if you have done everythign exactly as I have said over the past few weeks, the following commands should do the required copying

                    cd
                    cd cs206
                    cp Assignment2/*.java Assignment3/
              

  There are lots of other ways to accomplish this.
• Data files are in /home/gtowell/cs206/a3. The data should be read directly from these files. Do not make and read from local copies. (More precisely, the version you submit must not use a local copy.)
• Override the toString method of your Place class to return an appropriate string representation. For example, the Place for Bryn Mawr should return "Bryn Mawr, PA".
• Write a new class LocatedPlace that is a subclass of Place. Include appropriate instance variables, constructor and getters.
• The LocatedPlace class must have an overridden toString method that includes the location information in the string returned. For example, for Bryn Mawr it would return the string "Bryn Mawr, PA 40.02 -75.31".
• Write a new class PopulatedPlace that is a subclass of LocatedPlace. Include appropriate instance variables, constructor and getters.
• The PopulatedPlace class must override the toString method to include the place’s population in the string. For Bryn Mawr, this would yield "Bryn Mawr, PA 40.02 -75.31 21103".
• Modify the readZipCodes method from Places to read both data files, constructing an ArrayList of Place items. This ArrayList is used rather than the array of Assignment2. (If you encapsulated correctly, then no one outside the Places class will be affected by this change.) When a place’s population is known, it will be represented by a PopulatedPlace object. Otherwise, when a place’s location is known, it will be represented by a LocatedPlace object. Otherwise it will be represented by a Place object.
• readZipCodes should read each file only once. You should read in one file first, create objects to accumulate the partial data in that file, and then read the other file, combining the entries appropriately. The zipcodes in the files are not in the same order.
• Update the main method to work with your new methods. Recall that the appropriate toString() will be used when you print your three different Place objects.

  Here’s a sample session:

  zipcode: 19010  
  Bryn Mawr, PA 40.02 -75.31 21103  
   
  zipcode: 99400  
  No such zipcode  
   
  zipcode: 91729  
  Rancho Cucamonga, CA 34.09 -117.56  
   
  zipcode: 00000  
  Good Bye!
  The zip codes after "zipcode:" are input from the user.

Electronic Submissions

1. README:

The following steps for submission assume you are using Eclipse, and that you created a project named Assignment3 in the directory /home/YOU/cs206/

1. Put the README file into the project directory (/home/YOU/cs206/Assignment3)
2. Go to the directory /home/YOU/cs206/Assignment3/
3. Enter submit -c 206 -p 3 -d Assignment3