You are here

Detailed Lab Instructions

5 February, 2015 - 15:32

Read and follow the directions below carefully, and perform the steps in the order listed.

  • Navigate to your sub-folder: Chapter 03 and open and study the two files.
  • We have learned that a fundamental concept of interaction with computers is to divide the problem/task into three parts input, processing and output. This problem is simple and we will use the IPO (input processing output) approach again. However this time we are going to think about it backwards.

  • What output do I want displayed?
  • Number of gallons of paint
  • Total cost of the paint

  • Thus, what calculations do I need to make?
  • Total cost of the paint is the Number of gallons needed times price per gallon
  • Number of gallons needed is the Total area to be covered (let's use square feet) divided by the coverage per gallon of paint (Note: you must round up to the next full gallon of paint.)
  • Total area to be covered is the Length times height times 2 added to the width times height times 2

  • Which leads us to, what data do I need as input?
  • Price of a gallon of paint
  • Number of square feet that a gallon will cover
  • Length of the house
  • Width of the house
  • Height of the house

  • You can see that by working the logic backwards, we can start to completely see what the program must do. We need to enter some data (input), do some calculations (process) and display the results (output).
  • Copy into your sub-folder: Chapter 03 one of the source code listings that we have used (we suggest the Lab 01 source code) and rename the copy to: Lab 03.cpp
  • Modify the code to follow the Solution Lab 03 Pseudocode.txt file.
  • I am just going to give you the line of code for rounding up to the next whole gallon of paint (See the "Data Type Conversions" module within Chapter 3 of the Connexions materials. Do you understand why it works?).
  • total_gal_paint - total area / coverage_gal_paint + 0.9999;
  • Build (compile and run) your program. You have successfully written this program when it runs with your test data and gives the predicted results.

  • After you have successfully written this program, if you are taking this course for college credit, follow the instructions from your professor/instructor for submitting it for grading.