CS 151 - Introduction to Data Structures

Homework 2

Bags - Zipcode lookup

Due Sep 15, prior to 11:59:59 PM

Overview

Code is available by scp at
/home/gtowell/Public/151/A02/BagOfStuff.java
/home/gtowell/Public/151/A02/StuffBag.java Use cp or scp to get the code. For example:

                  scp YOURUNIXLOGIN@goldengate.cs.brynmawr.edu:/home/gtowell/Public/151/A02/BagOfStuff.java BagOfStuff.java
            

Data

ziplocs.csv

      "00705","STANDARD","AIBONITO","PR","PRIMARY",18.14,-66.26,"NA-US-PR-AIBONITO","false",,,
      "09005","MILITARY","APO","AE","PRIMARY",,,"EU-DE-WEISBADEN AAF OMDC","false",,,
      "10029","STANDARD","NEW YORK","NY","PRIMARY",40.71,-73.99,"NA-US-NY-NEW YORK","false",31490,48403,1050141146

      String ss = "\"asdf\"";
      System.out.println(ss);  // prints "asdf"
      ss = ss.replace("\"", "");
      System.out.println(ss);  // prints asdf

0. zip code
1. type -- ignored
2. city name
3. state abbreviation
4. type 2 -- ignored
5. Latitude
6. Longitude
7. long code -- ignored
8. true or false -- ignored
9. population 1
10. population 2
11. another number -- ignored

For this assignment we care about only: zip code, city name, state, latitude, longitude and population 2. Some lines are missing the longitude and latitude (like the second sample line), some are missing population as well as longitude and latitude. All lines have the correct number of commas (11). There are no lines for which the longitude and latitude are not known but the population is known.

Given this final statement, the data falls into 3 groups: 1: those for which location and population are known, 2: those for which only location is known, 3: those for which neither location nor population is known. You first task is to design a set of java classes so that each of these groups can be stored in a instance that is capable of storing the available information, and no more. These java classes MUST be linked to each other using inheritance. For instance, if you define a class Place that stores group 3 data, then you might make a class

      public class LocatedPlace extends Place

      public class PopulatedPlace extends LocatedPlace

Requirements

• You must store data in classes you create. These classes should hold exactly as much information as is contained in a row of the data file. If the row is missing a data item, then you should use a class that does not have space for the missing item. You may use the class design suggested above for your classes.
• You MUST use inheritance in your class design.
• The only Data Structure you should use in this assignment is StuffBag. You may use only one instance of StuffBag
• You may read the contents of ziplocs.csv at most once.
• When looking in StuffBag for a data item you must use the getInstance method. Do not write your own search. Rather, appropriately override the equals method of your classes. That is, write an equals method that determines if two items are equal by comparing ONLY their zip codes.
• After reading in the data, your program should support user interaction similar to the following:

  Enter a zip code to lookup (00000 to quit): 19380
          West Chester,PA 19380       Pop:43281  Lat:39.95  Lon:-75.60
  Enter a zip code to lookup (00000 to quit): 07040
        Maplewood,NJ 07040       Pop:20973  Lat:40.73  Lon:-74.27
  Enter a zip code to lookup (00000 to quit): 00614
        Arecibo,PR 00614       Lat: 18.45  Lon:-66.73
  Enter a zip code to lookup (00000 to quit): 09848
        Apo,AE 09848
  Enter a zip code to lookup (00000 to quit): 88888
        Not Found
  Enter a zip code to lookup (00000 to quit): q
  Goodbye
        

• All printing of information about a place should be done from toString. So, for instance, in the above interaction all of the printout of search results (other than "not found") should be done with a single line which might look like
  System.out.println(place);
• Encapsulation. All classes should expose only that which other classes need. There should be no public instance variables
• Statics. Do not use any static variables or static methods.
• Scanner. Use the java Scanner class for user interaction only. All files should be read using BufferedReader and parsed using the split method of the String class. (As from ReadCSV of Lab1 and Homework1.) I encourage you to look at homework 1 and think about how you might reuse some of that code in this homework. The basic split method of the Java String class (e.g., "a,,,b,,,,,".split(",")) has an interesting property. In this case, the returned array will be of length 4, not 9. That is, split will not extend the returned array to include space for trailing splits that have no data. I encourage you to NOT use this, rather use split "a,,,b,,,,,".split(",",25) which returns an array of length 9.

Electronic Submissions

1. README:

The following steps for submission assume that you created a project directory named Assignment2 in the directory /home/YOU/cs151/. Very briefly,

1. Put the README file into the project directory (/home/YOU/cs151/Assignment2)
2. Go to the directory /home/YOU/cs151/Assignment2/
3. Enter /home/gtowell/bin/submit -c 151 -p 2 -d Assignment2