Description
There are several fields in computer science that aim to understand how people use
language. This can include analyzing the most frequently used words by certain authors, and then going one step further to ask a question such as: “Given what we know about Hemingway’s language patterns, do we believe Hemingway wrote this lost manuscript?” In this assignment, we’re going to do a basic introduction to document analysis by determining the number of unique words and the most frequently used words in two documents.
Please read all directions for the assignment carefully. This write-up contains both
the details of what your program needs to do as well as implementation
requirements for how the functionality needs to be implemented.
What your program needs to do
There is one test file on Moodle – HungerGames_edit.txt that contain the full text from Hunger Games Book 1. We have pre-processed the file to remove all punctuation and down-cased all words.
Your program needs to read in the .txt file, with the name of the file to open set as a command-line argument. Your program needs to store the unique words found in the file in a dynamically allocated array and calculate and output the following information:
- The top n words (n is also a command-line argument) and the number of
times each word was found
- The total number of unique words in the file
- The total number of words in the file
- The number of array doublings needed to store all unique words in the file
There is a link to a class video on command-line arguments in the Resources
section of piazza.
Example:
Running your program using:
./Assignment2 HungerGames_edit.txt 10
would return the 10 most common words in the file HungerGames_edit.txt and
should produce the following results.
682 – is
492 – peeta
479 – its
431 – im
427 – can
414 – says
379 – him
368 – when
367 – no
356 – are
#
Array doubled: 7
#
Unique non-common words: 7682
#
Total non-common words: 59157
Program specifications
Use an array of structs to store the words and their counts
There are specific requirements for how your program needs to be implemented. For this assignment, you need to use an array of structs to store the words and their counts. The members of the struct are left to you, but keep it as simple as possible.
Exclude these top 50 common words from your word counting
Table 1 shows the 50 most common words in the English language. In your code, exclude these words from the words you count in the .txt file. Your code should include a separate function to determine if the current word read from the .txt file is on this list and only process the word if it is not.
|
Table 1. Top 50 most common words in the English language
| 15 | With | 32 | An | 49 | Go |
| 16 | He | 33 | Will | 50 | Me |
| 17 | As | 34 | My |
Use two command-line arguments
Your program needs to have two command-line arguments – the first argument is
the name of the file to open and read, and the second argument is the number of
most frequent words to output. For example, running
./Assignment2 HungerGames_edit.txt 20
will read the HungerGames_edit.txt file and output the 20 most common words
found in the file.
Note: There is a link to a class video on command-line arguments in the Resources
section on Piazza.
Use the array-doubling algorithm to increase the size of your array
We don’t know ahead of time how many unique words either of these files has, so you don’t know how big the array should be. Start with an array size of 100, and double the size as words are read in from the file and the array fills up with new words. Use dynamic memory allocation to create your array, copy the values from the current array into the new array, and then free the memory used for the current array. This is the same process you used in Recitation 3.
Note: some of you might wonder why we’re not using C++ Vectors for this
assignment. A vector is an interface to a dynamically allocated array that uses array doubling to increase its size. In this assignment, you’re doing what happens behind- the-scenes with a Vector.
Output the top n most frequent words
Write a function to determine the top n words in the array. This can be a function that sorts the entire array, or a function that generates an array of the n top items. Output the n most frequent words in the order of most frequent to least frequent.
Format your output the following way
When you output the top n words in the file, the output needs to be in order, with
the most frequent word printed first. The format for the output needs to be:
Count – Word
#
Array doubled: <number of array doublings>
#
Unique non-common words: <number of unique words>
#
Total non-common words: <total number of words>
Generate the output with these commands:
cout<<numCount<<” – “<<word<<endl;
cout<<”#”<<endl;
cout<<”Array doubled: “<<numDoublings<<endl;
cout<<”#”<<endl;
cout<<”Unique non-common words: “<<numUniqueWords<<endl;
Submitting Your Code:
Submit your assignment to the COG autograder:
https://web-cog-csci2270.cs.colorado.edu/submit.html.
Login to COG using your identikey and password. Select the CSCI2270 – Hoenigman
– HW #02 from the dropdown. Upload your file and click Submit. Your file needs to be named Assignment2.cpp for the grading script to run. COG will run its tests and display the results in the window below the Submit button. If your code doesn’t run correctly on COG, read the error messages carefully, correct the mistakes in
your code, and upload a new file. You can modify your code and resubmit as many
times as you need to, up until the assignment due date.
Submit your assignment to Moodle
In addition to submitting through COG, submit your .cpp file through Moodle using the Assignment 2 Submit link. Make sure your code is commented enough to describe what it is doing. Include a comment block at the top of the .cpp file with your name, assignment number, and course instructor. If you do not submit your work to Moodle, we will deduct points from your grade, even if COG gives you a perfect score.
If you do not get your assignment to run on COG, you will have the option of
scheduling an interview grade with your TA to get a grade for the assignment. Even if you do get the assignment to run on COG, you can schedule the interview if you just want to talk about the assignment and get feedback on your implementation.
What to do if you have questions
There are several ways to get help on assignments in 2270, and depending on your question, some sources are better than others. There is the Piazza forum that is a good place to post technical questions, such as how to shift an array. When you answer other students’ questions on the forum, please do not post entire assignment solutions. The CAs are also a good source of technical information, especially questions about C++. If, after reading the assignment write-up, you need clarification on what you’re being asked to do in the assignment, the TAs and the Instructor are better sources of information than the discussion forum or the CAs.
