Computer Science 261

Assignment # 5

Due: Wednesday, Oct. 10

Purpose:

• To develop the first in a series of programs exploring data structures that can be used to store a list of objects with a standard interface.  To learn the advantages and disadvantages of each approach.  In the course of the next several exercises in 'lists of objects', we will cover 
• Storing objects in linked lists
• Storing objects in binary search trees
• (if time permits) Hash tables and indexes
• Please note that Java already contains built-in data structures to do all this.  Our purpose is to learn how they work so that we can make informed choices about which one to use in a particular situation, and also to be able to use them in programming languages that are not as rich in data structures as is Java.

• Fields
  • Array of part objects (from earlier assignment)
  • Inventory size (actual number of parts in the inventory)
  • sorted (an internal flag to say if the array is in order by the PNo field).
• Methods
• Constructor accepting an integer which represents the maximum number of objects in the inventory.  This constructor will then create the array of part objects with that many elements in it.
• Other Methods
  • print - prints a listing of all the parts in the inventory. You can do this by using the PartObject's print method, or by using the GetPartNumber, etc. commands to get the contents of individual fields and generate a nicely formatted listing. The list should be in ascending part number order. If it is not, the sort routine (see below) should be called to sort the array.
  • AddPart - accepts a part object as an argument, adds it to the list. If the array is full, or if the part already exists, print a message and return doing nothing. Important note: We will later want to throw an exception in this sort of case. Please don't do this here - the test driver program will not be written to catch exceptions.  
  • DeletePart - accepts a part number as an argument) and deletes the corresponding object if it is in the inventory. If not in the inventory, print a message and return doing nothing. As discussed Tuesday, you can delete either by moving everything up into the cell that has been deleted (preserving the sort order), or by moving the last element of the array into the location being deleted.
  • FindPart - accepts a part number as an argument and returns the part with that part number if found. If not found returns null. If the array is in order by part number, use a binary search, otherwise use a sequential search  Note that this public routine will also be useful internally in AddPart (to check for an existing part), and DeletePart.
  • sort (a private routine, only for use by the print routine). Sort the array in ascending order by part number.

I will shortly provide a main program to test your program out

Questions?  Please ask!