pizza design evolution

<body stylesrc="comment1.htm" bgcolor="#FFFFFF"> <p align="center"> </p> <p align="center"> </p> <table border="4" width="100%" height="60"> <tr> <th><h1><font size="5">CS 150 Introduction to C++ Programming - Spring 1998 </font></h1> </th> </tr> </table> <p align="center">[ <a href="http://www.cs.odu.edu/~cs150" target="_top">Home</a> |<a href="ftp://ftp.cs.odu.edu/pub/ray/150"> Lecture Notes</a>| <a href="http://www.cs.odu.edu/~wild/cs150">WebTutor</a> | <a href="http://www.cs.odu.edu/~wild/cs150/site.cgi" target="_top">WebTutor Site Map</a>]</p> <hr> <h2 align="center">Commentary on Incremental Design</h2> <p align="left">This frame contains commentary on the developing incremental design shown in the right frame.</p> <p align="left">It is also used to move through the developing design stages. You can always start over by <a href="pizza0.htm" target="program">clicking here.</a></p> <p align="left">When you are ready, <a href="pizza1.htm" target="program">click here to show the initial skeletal design.</a></p> <p align="left">PIZZA Step 1:</p> <p align="left">Basically this is the skeletal C++ program with comments indicating where certain parts of the C++ program should go.</p> <ul> <li>File documentation (first two lines) </li> <li>Place for including necessary libraries (almost always needed)</li> <li>main function of the program and its beginning and end braces around its body)</li> <li>place for constants (if any), Constants are highly recommended for readability and changeability</li> <li>declarations of any variables need to store program information</li> <li>statements which execute when the program is run and which produce the results of the program</li> <li>return statement when the program is done</li> </ul> <p>This program will compile and execute, but of course does nothing.</p> <p><a href="pizza2.htm" target="program">Click here for PIZZA step 2:</a></p> <p>Many problems have three distinct parts:</p> <ul> <li>Get any input data</li> <li>Process the data to produce the results of the program</li> <li>Output the results</li> </ul> <p>Such problems have an Input/Process/Output (IPO) structure.<br> So we have added some comments, which expand the executable statements into these three parts.<br> Notice that adding the IPO comments expands, or refines, the executable part of the previous design step.<br> This is also known as the process of SUCCESSIVE REFINEMENT which will continue until we are satisfied with the design.</p> <p>(for this and subsequent versions, we will show the new part of the design in <font color="#FF0000"><strong>BOLD red letters</strong></font> and the <em>old part in italics</em>)</p> <p>Now let's give the specification for this case study: the Monastery Pizza Problem:</p> <table border="1"> <tr> <td>The new pizza company, The Monastery, requires the development of an automated pricing and ordering system. The company has a work place where the orders are taken, one section for walkin ordering, and another for phone ordering. These orders are then given to the preparation section where the orders are filled, baked, and boxed <p>The company offers three different shapes of pizza, round (either 12 or 16 inch), square (either 14 or 16 inch), and a 12 inch by 24 inch rectangle. The company has decided to price their pizza simply by considering the area of each pizza and using that value to calculate the overall cost of the delivered product. The cost per square inch of pizza has been fixed at 2.5 cents.</p> <p>Their pizza is prepared with any single topping without cost, thus any pizza ordered with either extra cheese or pepperoni, or sausage etc. has no additional charge. For every topping after the one, an additional charge of 0.3 cents per square inch of pizza is added to the cost. </p> <p>Prepare a proposed solution that could be used to write a C++ program that would accept the order and prepare the customer's bill. The bill should always be rounded to the next highest increment of 50 cents prior to the imposition of the state sales tax of 8%.</p> </td> </tr> </table> <p><a href="pizza3.htm" target="program">Click here for PIZZA step 3:</a></p> <p>You can work on any unfinished part to do the next refinement.<br> But it is natural to work on the input since this also forces us to think about what variables are need to remember the input values.</p> <p>Analyzing the problem specification, we can easily identify several pieces of information which the user must enter in order for the program to calculate the cost.</p> <ul> <li>Pizza Shape</li> <li>Pizza Size</li> <li>The number of kind of toppings</li> </ul> <p>It is not important that you get everything at this point. You can always add more later. For instance, a little reflection on the problem might make you realize that you should also include the customer's name (and maybe telephone number - but let's stop with this).</p> <p>So we have added several comments to the variable declarations sections for these pieces of information.<br> Also we have added an executable statement comment which indicates that we actually need to input this information.</p> <p><a href="pizza4.htm" target="program">Click here for PIZZA step 4:</a></p> <p>Since we are not yet comfortable with what it means to process the input to produce results, we refine that part now.<br> Basically we need to prepare the bill. This means calculating how many square inches of pizza, calculating the cost, rounding and taxing.</p> <p><a href="pizza5.htm" target="program">Click here for PIZZA step 5:</a></p> <p>Since computing the pizza cost is complicated by the charge for toppings, we refine that step next.</p> <p><a href="pizza6.htm" target="program">Click here for PIZZA step 6:</a></p> <p>Now we refine the output part to produce an output label to go on the pizza box.</p> <p>So how do you know when to stop refining?<br> One criteria you could apply, is to stop when each step is fairly obvious to you.</p> <p>So what is next after refining the design?<br> Well it needs to be changed into a C++ program.<br> But we are not ready for that just yet. (however the skeleton still should compile OK and do nothing very well).</p>  </body>