Introduction

The assignment for this week will utilize concepts of I/O data streams and string manipulations.

We will also be grading for meeting requirements, using “class legal” code, and plagiarism. So, it is not enough for your lab to just pass the Gradescope autograder! Please read the instructions herein carefully.

It is highly recommended that you develop the algorithms for each program first and then develop the C++ code for it.

Step 1: Getting ready

Either through a graphical file system explorer or through the terminal:

1. Navigate to your cs16 directory:
   • For example, from the terminal:

   $ cd cs16

2. Create and navigate to the lab6 directory:
   • From example, from the terminal:

   $ mkdir lab6
   $ cd lab6

Step 2: Create and edit your C++ programs

This week, you will need to create 2 C++ programs called stats.cpp and rhymes.cpp. Each of the C++ programs corresponds to one of the problems listed below, which make up this lab. Each is worth 50 points and should be solved in its own file and both must be submitted for full assignment credit.

Important Note: We will take major points off if you use C++ instructions/libraries/code that either (a) was not covered in class, or (b) was found to be copied from outside sources (or each other) without proper citation.

stats.cpp

This program takes its inputs from a file that contains an indeterminate number of floating-point numbers. The program reads them in as type double. The program outputs to the screen the mean (average), the median, and the standard deviation of the numbers in the file. The file contains nothing but numbers of type double separated by blanks and/or line breaks. For this exercise, the average is the sum of all the numbers divided by the count of these numbers. The median is the number that is in the middle of the list, where 1⁄2 of the numbers in the list are smaller than the median and the other 1⁄2 of the numbers is larger than the median. If there are an even number of numbers, then the median is the average of the 2 middle numbers. The standard deviation of a list of numbers \(x_1, x_2, x_3, \ldots, x_n\) is defined as:

\[\begin{equation*} \sqrt{((x_1 − a)^2 + (x_2 − a)^2 + \ldots + (x_n - a)^2) / (n − 1)} \end{equation*}\]

Where the number \(a\) is the average of \(x_1, x_2, x_3, \ldots, x_n\).

Requirements

1. Your program should take filename as an input from the user—it does not need to check if the input filename is valid.
2. The answers should be given with exactly 3 decimal points.
3. You can safely assume that the number files will never have more than 1000 numbers in them.
4. Your program should define at least 3 functions that only do the calculations for the mean, median, and standard deviation (they must not print to standard out) and return the values back to the function caller.
   1. You can have additional functions, if you like.
   2. If your program does not have these 3 functions, you will not get credit for this part of the assignment, even if your program passes the Gradescope autograder.
   3. You can pass the output of the mean function into the standard deviation function, if you want (would be helpful).
5. Be sure to utilize only techniques we’ve covered in lecture. Do not use “special” arrays, do not use vectors, do not use built-in sorting functions, etc. You will get zero points if you do. You have to calculate mean, median, and standard deviation using the “classical” methods talked about here—no short cuts.

Let’s say the input file, nums1.txt, contains this (note the separation by whitespaces):

6 9
7
8

Then, a session should look exactly like the following example (including whitespace and formatting—note that there is no whitespace at the end of each of these lines and each printed line has a newline at the end).

Enter filename: nums1.txt
Mean = 7.500
Median = 7.500
Stddev = 1.291

Let’s say that another input file, nums2.txt, contains this (note the separation by whitespaces):

1.2 4.2 0 10 5

Then, a session should look exactly like the following:

Enter filename: nums2.txt
Mean = 4.080
Median = 4.200
Stddev = 3.900

One more example: consider input file, nums3.txt, which contains:

55.8 86.9 2.4 16.8 5.9 10.2 11.2 25 96.1 4 12.7 81.7 60.4 72.1 52.1 39.6 24.2 2.6 52.3 49.9 14.4
90.9 48.1 88.6 44.3 51.1 55.1 77 33.4 8.4 66.2 89.2 95.3 68.6 41.2 36.5 14 52.4 96.7 10.2 91.7 44.6
27.1 52.1 16.7 79.2 91.7 76.1 81.8 79.3

Then, a session should look like this:

Enter filename: nums3.txt
Mean = 49.676
Median = 51.600
Stddev = 30.633

You will only be submitting the C++ file, stats.cpp (there is no skeleton or starter file). We will test it with several different number files.

rhymes.cpp

Write a program that finds rhyming words in a poem!

Specifically, the program reads an input file, line by line, and extracts the last word in each line. It then compares this last word with the last word from the line after it. If it finds that the 2 words “rhyme” (which is simply defined as the 2 words that are being compared share the same 2 last letters), then it prints out these two words to standard output (i.e. the display).

It also displays the number of lines in the poem along with a metric called “the rhyme-line density” which is the number of rhymes found divided by the number of lines in the poem.

But first, the words must be cleaned up of any non-alphabetical characters (usually this means punctuation, since many poems have their last lines often end with a comma, a semicolon, a question-mark, etc.) So, if the last word on a line has punctuation marks on it, e.g. “hello?!”, it becomes “hello”. Or if the last word is “don’t”, it becomes “dont”.

Finally, the program has to state how many rhyming pairs it found, or if it did not find any at all.

Requirements

1. Your program should take filename as an input from the user—it does need to check if the input filename is valid.
   1. If it does not exist, the program must output (via cerr) an error message: Input file opening failed. and then exit with return code 1.
2. Your program should define at least 3 functions that only do last-word extraction, word-end comparisons, and word clean-up.
   1. You can have additional functions, if you like.
   2. If your program does not have these 3 functions, you will not get credit for this part of the assignment, even if your program passes the Gradescope autograder.
3. When displaying the rhyme-line metric, only show 2 places after the decimal point.
   1. If there are no rhymes found, you do not need to show the metric (see examples below).
4. Be sure to utilize only techniques we’ve covered in lecture. Do not use “special” arrays, do not use vectors, do not use built-in sorting functions, etc. You will get zero points if you do.

As an example, assume there is a text file called MyPoem.txt, which contains this:

"I cannot go to school today,"
Said little Peggy Ann McKay.
"I cannot go to school and play!
I have the measles and the mumps,
A gash, a rash and purple bumps.
My mouth is wet, my throat is dry,
I’m going blind in my right eye.
My tonsils are as big as rocks,
I’ve counted sixteen chicken pox"

The program would run as follows.

Enter filename: MyPoem.txt
today and McKay
McKay and play
mumps and bumps
There are 3 pairs of rhyming words.
There are 9 lines in this poem, so the rhyme-line density is: 0.33

Note that, in this poem, “dry” and “eye” were not shown, nor were “rocks” and “pox”. This is because they do not meet the program’s criteria of a “rhyme”. Also note the last line of the output says how many pairs of rhyming words there are. Please make the word “pair” singular if only 1 pair of rhyming words is found and use the plural “pairs” if you found more than 1 rhyming pairs.

So, for example, with a file called Simple.txt:

I do not like green eggs and ham,
I do not like them Sam I am.

The program would run as follows:

Enter filename: Simple.txt
ham and am
There is 1 pair of rhyming words.
There are 2 lines in this poem, so the rhyme-line density is: 0.50

Finally, consider this example file called No.txt:

No means no, it always means no
If I say it once it means
A thousand times no!

The program would run as follows:

Enter filename: No.txt
No rhymes found.
There are 3 lines in this poem.

Note that no rhymes were found because the program only looks at adjacent lines. Also, note that the case of no rhymes found will not display the rhyme-line metric.

You can assume that:

1. Text files may be empty (have no line), and may contain blank lines, but lines that are not blank will have at least 2 words per line.
2. The last words on a line contain at least 2 characters.
3. The rhyme comparison is case-sensitive.
4. Blank lines should be treated as empty strings. DO NOT REMOVE OR SKIP BLANK LINES.

You will only be submitting the C++ file, rhymes.cpp (there is no skeleton or starter file). We will test it with several different rhyme files.

Step 3: Create a makefile and compile the code

In order to learn another way to manage our source codes and their compilations, we will first create a makefile and put in the usual g++ commands in it. Afterwards, whenever we want to compile our programs, the command is a lot shorter—so this is a convenience.

Using your text editor, create a new file called makefile and enter the following into it:

all: stats rhymes

stddev: stats.cpp
    g++ -o stats stats.cpp -Wall -std=c++11

rhymes: rhymes.cpp
    g++ -o rhymes rhymes.cpp -Wall -std=c++11

Then from the command line, you can issue one command that will compile this code, like so:

$ make

Or, you can issue separate compile commands for each project, like so:

$ make stats

If the compilation is successful, you will not see any output from the compiler. You can then run your program like this:

$ ./stats

or

$ ./rhymes

If you encounter an error, use the compiler hints and examine the line in question. If the compiler message is not sufficient to identify the error, you can search online to see when the error occurs in general.

Remember to re-compile the relevant files after you make any changes to the C++ code.

Step 4: Submit your programs for grading

Once you are satisfied your programs are correct, then it’s time to submit them. While working with others is OK, you still must submit your own lab. Even if you’re working with another person, do not copy each other’s code.

Log into Gradescope and select CMPSC 16 under Summer 2021, and navigate to the Lab 6 assignment. Then click on the “Upload Submission” button on the bottom right corner to make a submission.

You will be given the option of uploading files from your local machine or submitting code from a GitHub repo. Follow the steps to upload both stats.cpp and rhymes.cpp to Gradescope (do not upload any other files). If your files do not have those exact names as presented in this lab, the autograder will not grade them. You can resubmit your files as many times as you like before the assignment deadline.