CheckPoint: Chapter 2 Programming Problem

Associate Program Material

Appendix E

System-Level Requirements Example

Consider the Input and Output Process Example program in Appendix B, in which you developed what are often called system-level requirements: the basis for all subsequent analysis and design steps. The following steps will take these system-level requirements and refine them into a detailed blueprint for the program.

Up to this point, you have identified the processes the program must perform, but you have not given any consideration to exactly how the processes work together to solve the problem. At this point, you must generate a description of the processing using pseudocode, a natural language description of the processing the application must perform.

The natural place to start is the system-level requirements you identified in the input-process-output (IPO) chart. Determine how the processes work together: Once you have determined the top-level logic, you can design each individual process. This step-wise refinement process allows you to conceptualize a vague problem into increasing levels of details to actually generate a working program. This point is important because the step-wise refinement process is used throughout the entire program development—each new piece of information is based on, and is a refinement of, the information uncovered in the previous step.

For this week’s CheckPoint, you will refine the IPO table into a complete design, as demonstrated on pp. 80 & 83 in Ch. 2 of Prelude to Programming. Additionally, refer also to the Input and Output Process Example in Appendix B to see how more detailed analysis and design relates to the previously constructed IPO chart.

The following information demonstrates all the items you need to develop your programming assignments and the final project.

Analysis

Process:

1. Get user input.

2. Find the room area.

3. Divide the room area.

4. Multiply gallons.

5. Prompt for ounces.

6. Display total.

price (real: 0-100)

squareFeetPerGal (real: 0-1000)

width (real: 0-100)

length (real: 0-100)

height (real: 0-100)

Input:

Output:

total_cost (real: > 0)

Design

Main Module

Declare price as real

Declare squareFeetPerGal as real

Declare width as real

Declare length as real

Declare height as real

Declare totalArea as real

Declare gallonsNeeded as real

Declare outputPrompt as string

Declare totalCost as real

Get user input

Find the room area

Divide the room area

Multiply gallons

Display total

End Main Module

Input Data Module

Write, “What is the price per gallon of paint?”

Input price

Write, “How many square feet does each gallon cover?”

Input square_feet_per_gal

Write, “What is the height of the walls?”

Input height

Write, “What is the width of the walls?”

Input width

Write, “What is the length of the walls?”

Input length

End Input Data Module

Find Room Area Module

Declare sideArea as real.

Declare frontBackArea as real.

Declare ceilingArea as real.

sideArea = 2*(length * height)

frontBackArea = 2*(width * height)

ceilingArea = width * length

totalArea = sideArea + frontBackArea + ceilingArea

End Find Room Area Module