A6-Loopy Programs

Table of Contents


Objectives

  • Apply counting loops to display data
  • Use indefinite loops to gather data
  • Develop the ability to find minimum and maximum values
  • Code nested loops

Academic Honesty

Read the Scholastic Honesty Policy and Assignment Integrity policies of the syllabus. Here are some clarifications for this particular assignment:

  • You are encouraged to work with one other student of this class following the rules of Pair Programming for Homework Assignments. If you choose to pair program, there is a bonus applied.
  • You may not give a copy of your code to your designated pair-programming partner if you did not develop the code together.
  • You may not show your completed code to another person or look at another person's code until you complete and submit this assignment, except for code you develop together with your pair-programming partner.
  • You may get help from people other than your pair-programming partner if you get stuck, but only if they do not show or tell you the code to type.
  • Remember that the instructor performs similarity tests on programming project submissions, and plagiarized code is usually very easy to detect.

Preparation

  1. Make sure you have completed the exercises from lesson 5 and lesson 6.
  2. Complete the Review Exercises in CodeLab 5 and 6. These exercises will help prepare you for the problem-solving programs and should be completed first.

Project Specifications

Your solutions to these projects must only use techniques we have covered so far.

Programming Style

For all programs, remember to follow all the style rules we covered including the recent items:

  1. No magic numbers
  2. Indentation in while statements and placement of curly braces
  3. No tab characters in your code.

    You can remove tab characters by either setting up TextPad correctly (see here) or by running a program named astyle (see here).

  4. Meaningful variable names and consistent naming style (caps vs. underbars).

Image
Source: Kiryl Sytsko
(Public Domain)

Project 1: Loopy Characters

Counting loops are very commonly used in programming to ... count things. Character data types are used to store and display individual letters and other symbols. In this project we explore both counting loops and characters in C++.

Project Specifications
  1. Start by downloading the worksheet: loopychars.cpp.

    Keep the same filename and add to the existing code to complete the project. Leave the existing code unchanged, except for comments as instructed.

  2. Add your name and the date to the file comment block at the top of the file.
  3. User input is already coded into the worksheet, consisting of an integer number, n, and a single character.

    Do not add any other input commands or change the input order. Assume the user enters only valid data.

  4. Use a for-loop to print the character entered by the user the number of times specified by the integer number typed in. See the Example Run for an example.

    Hint: see Exercise 5.1a step 3 for an example for-loop. Change max to n and print ch instead of i.

  5. Use a second for-loop to print the character entered by the user followed by the subsequent n - 1 characters in the ASCII table. See the Example Run for an example.

    Hint: In this loop, we are adding the index value to the character typed in by the user. This is like when we added i to sum in lesson 5.1.3. We can add a number to ch because of the ASCII character codes. To keep the value of ch, declare another char variable or use casting (see lesson 4.1.6).

  6. Use a third for-loop to print the character n / 2 times with a '*' instead of the character on even counts of the loop as shown in the Example Run.

    Hint: Use and if-statement to test for even or odd counts of the loop, like we tested for Chitter or Chatter in squirrel logic.

  7. Use a fourth for-loop to print the character n times with a tick mark '+' substituted every fifth character as shown in the Example Run.

    Hint: Use and if-statement to test for the every fifth count of the loop. Start the for-loop count from 1, but check the end condition! Only print the number if nothing else is printed.

  8. Use yet another loop to print the previous loop n times. Thus, this problem should use two loops.

    Hint: put your for-loop from the previous challenge inside another for-loop that has a different counting variable. Print a newline character inside the outer loop after the inner loop completes.

  9. Example Run: The input prompts and outputs of the program must look like the following for full credit, including the same order of input and wording of the output. For the input shown you must get the same output. However, the output must change properly if the inputs are different.
    ** Loopy Characters! **
    
    Enter an integer between 1 and 20: 10
    Enter a single character: A
    
    #1. Printing A 10 times:
    AAAAAAAAAA
    
    #2. Printing starting with A and the following 9 ASCII characters:
    ABCDEFGHIJ
    
    #3. Printing A character 10 times substituting '*' on odd indexes:
    A*A*A*A*A*
    
    #4. Printing A character 10 times substituting (+) every fifth character:
    AAAA+AAAA+
    
    #5. Printing 10 lines of the previous loop:
    AAAA+AAAA+
    AAAA+AAAA+
    AAAA+AAAA+
    AAAA+AAAA+
    AAAA+AAAA+
    AAAA+AAAA+
    AAAA+AAAA+
    AAAA+AAAA+
    AAAA+AAAA+
    AAAA+AAAA+
    

    In the above example run, the user entered the values shown in italics (for emphasis) to produce the output. Your program does NOT print the characters in italics, nor does the user input appear in italics.

  10. After displaying the output, exit the program.
  11. Submit the source code file loopychars.cpp with the rest of the assignment as described in Deliverables.

Image
Image source: Public Domain

Project 2: Humpty Dumpty

In this project we use a for loop to print parts of a well-known nursery rhyme.

Humpty Dumpty sat on a wall,
Humpty Dumpty had a great fall.
All the king's horses and all the king's men
Couldn't put Humpty together again.

Project Specifications
  1. Create a source code file named humpty.cpp and include all your code in this single file.

    Be careful of the spelling, including capitalization, as you will lose points for a misspelled name. Naming is important in programming.

  2. Write a program that asks the user for a single maximum number, and no other input, as shown in the Example Run.
  3. Code a single for-loop to print the numbers from 1 to the maximum number entered by the user, with each number printed on its own line.
  4. When the loop count reaches a multiple of five print "Humpty" instead of the number.

    Hint: put an if-statements inside the braces of the for-loop.

  5. When the loop count reaches a multiple of seven print "Dumpty" instead of the number.
  6. For numbers which are multiples of both five and seven print "Had a Great Fall" instead of the number.
  7. Example Run: The input prompts and outputs of the program must look like the following for full credit, including the same order of input and wording of the output. For the input shown you must get the same output. However, the output must change properly if the input is different.
    Enter a positive number for the ending loop count: 35
    1
    2
    3
    4
    Humpty
    6
    Dumpty
    8
    9
    Humpty
    11
    12
    13
    Dumpty
    Humpty
    16
    17
    18
    19
    Humpty
    Dumpty
    22
    23
    24
    Humpty
    26
    27
    Dumpty
    29
    Humpty
    31
    32
    33
    34
    Had a great fall
    

    In the above example run, the user entered the value shown in italics (for emphasis) to produce the output. Your program does NOT print the characters in italics, nor does the user input appear in italics.

  8. Submit this project with the rest of the assignment as described in Deliverables.
Hints:
  • Put several if-else statements inside the braces of the single for-loop.
  • Test for numbers that are multiples of both 7 and 5 first.

Image
Image source

Project 3: Real or Fake News Detector

Fake, or hoax, news websites deliberately publish made-up stories as news, using social media to drive web traffic and amplify their effect [1]. This is a form of dishonesty known as a scam or swindle, and has been a boon for people trying to make a quick profit. Profit for fake news sites is primarily driven by online advertising revenue made mostly through Facebook and Google [2]. Both Google and Facebook have announced measures to ban web sites that show illegal or misleading content [3][4][5]. Do NOT confuse fake news with opinionated analysis from sites made on the basis of their ideologies.

For this project you are to write a program to help identify fake (made up) news. The instructor is providing you with five (5) "news" samples from the internet for testing your program. Three (3) of the samples are fake news articles and two (2) are real news articles. You must decide which are fake and which are real and write your program to identify them correctly.

Project Specifications
  1. Write a program that scans a "news" article and decides if it is real or fake. The instructor will use the following articles for testing:
    1. creditlock.txt
    2. equifax.txt
    3. golf.txt
    4. nibiru.txt
    5. reporters.txt
  2. The name of the source code file for this program must be realfake.cpp and all your code must be in this file.

    Be careful of the spelling, including capitalization, as you will lose points for a misspelled name. Naming is important in programming.

  3. Your program must run from the command line using redirection of input as follows:
    ./realfake < input.txt
    

    Where input.txt is the news article file to test.

  4. Your program must print out a single word "Real" or "Fake" (without the quote marks) when run, depending on the article scanned, like this:
    ./realfake < input.txt
    Fake
    
  5. Your program must correctly output the word "Fake" on three (3) articles and "Real" on two (2) articles based on the contents of the articles.
  6. After printing the appropriate word, exit the program. Do NOT loop and run again.
  7. Submit this project with the rest of the assignment as described in Deliverables.
Hint:
  • Review lesson 6.2.5: Processing Text Input and choose a way to process text for your approach. Try processing one of the files with both looping techniques and see which one would be easier for you.
  • After viewing the output of both looping techniques, think of the if-statements you will need to find a unique word or line in each of the files. Ideally, make your detector extensible to similar "news" articles.
  • Your final program should have a single while-loop and several if-statements inside the loop.
References
  1. Snopes' Field Guide to Fake News Sites and Hoax Purveyors
  2. Facebook and Google move to kick fake news sites off their ad networks
  3. Google Advertising Policies -- Misrepresentation
  4. Facebook -- Mark Zuckerberg Post 11/18/2016
  5. News Feed FYI: Addressing Hoaxes and Fake News (Facebook)
  6. An Update On Information Operations On Facebook
Resources

Here are some resources to help you get started solving the problem:

These sources may or may not correctly list fake news sites. You must research and decide for yourself.

Extra Credit

The following are worth extra credit points:

  1. Complete the assignment using pair programming with the same person for all three projects. (2 points)
  2. Display fake and real for the actual fake and real news sites. (1 point)
  3. Play the extra credit game: Lightbot 1. (2 points)
    1. Requires flash installed and does NOT work on Chrome.
    2. Complete the game through level 9
    3. Record the message shown at the beginning of level 10 in your README.txt under Extra Credit.
    4. Please do not cheat. If you get stuck, just explain how far you got in the README.txt and record the message for the level you completed.
    5. If you go beyond level 9, make certain to still record the message for the beginning of level 10.

Make certain that your README.txt file describes any extra credit attempted.

Tutorial Lab

In preparation for next weeks lessons, complete the following:

  1. Read the assigned reading in the textbook
  2. Complete the Tutorial Exercises in CodeLab 6 before the specified due date.

    Refer to the assigned reading for the next lesson to help you understand the problems. Also, you can use the online lecture notes for more information as the notes become available. You can look at solutions if you miss your first few attempts and are stuck by clicking the "Solution" tab.

Grading Criteria

The instructor will evaluate your assignment using the following criteria. Thus you should check your assignment against these criteria to maximize your score.

Each criteria represents a specific achievement of your assignment and has a scoring guide. The scoring guide explains the possible scores you can receive. Some scoring guides have a list of indicators. These indicators are a sign of meeting, or a symptom of not meeting, the specific criterion. Note that a single indicator may not always be reliable or appropriate in a given context. However, as a group, they show the condition of meeting the criterion.

For information on grading policies, including interpretation of scores, see the syllabus.

Lesson Exercises

  • 2: All lesson exercises attempted and turned in
  • 1: Some lesson exercises completed and turned in
  • 0: No lesson exercises completed or turned in

Programming Projects (x3)

  • 5: Demonstrates mastery of the program
    • Applies concepts from the lessons appropriately
    • Meets all specifications (see above)
    • Runs to completion with no abnormal error conditions
    • Generates correct output given correct input
    • Correct file name
  • 4: Has most of the functionality expected of the program
    • Demonstrates some techniques from the lesson
    • Attempts to meet all but one of the specifications (see above)
    • Implementation seems more complicated than necessary.
    • May have one minor error
  • 3: Has some of the functionality expected of the program
    • Demonstrates some techniques from the lesson
    • Attempts to meet at least 1/2 of the specifications (see above)
    • Implementation seems excessively complicated.
    • May have 2-3 minor errors
  • 2: Serious functional problems but shows some effort and understanding
    • Attempts to meet less than 1/2 of the of the specifications (see above)
    • Has a major error or many minor errors
    • Implementation seems very convoluted
    • Demonstrates few techniques from the lesson
  • 1: Does not compile or wrong file turned in
  • 0: Not turned in or uses techniques not covered

Programming Projects Style

  • 3: Code is well-documented including:
  • 2: Code has a minor documentation error
  • 1: Code has some documentation errors
  • 0: No apparent attempt to follow documentation standards or write documentation comments

CodeLab and Other Tutorial Exercises

  • Number CodeLab completed correctly / number exercises * 8 and rounded up to the nearest integer.

README.txt File

  • 2: README.txt file submitted following the instructions
  • 1: README.txt file submitted but some information was missing
  • 0: No README.txt file submitted

Total possible: 30, plus extra credit

Deliverables

Submit your assignment to Canvas, in the assignment folder that matches the name of this assignment, following the instructions for submitting homework. Include the following items for grading:

  1. README.txt file with option extra credit information
  2. All the exercise files from Lesson 5 and Lesson 6 including:
    • counting.cpp
    • countdown.cpp
    • scores.cpp
    • findword.cpp
  3. loopychars.cpp
  4. humpty.cpp
  5. realfake.cpp

You must submit all the files needed to complete your assignment. Your assignment must work as submitted. Remember to test and double check your files before submitting them. If you make a mistake, you can resubmit up to the deadline. If you resubmit, you must include all your assignment files in the last submission as Canvas hides prior submissions.

Last Updated: October 17 2017 @17:14:20