Assignment 4 Advanced Lists and Strings

COMP 1005/1405 
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Assignment 4
Advanced Lists and Strings
Submit a single zip file called assignment4.zip.
This assignment has 30 marks.
See the marking rubric that is posted on the course webpage.
Problem 1 (Queue)
A queue is a data structure use to store items. The next item removed from a queue is always
the item that has been in the queue the longest (i.e., was added first - think of a line of people
waiting to buy something). In this question, you will use a list to implement a queue and write
several functions to perform operations on the queue. For this question, you may not use
classes and/or object-oriented programming in your solution. Your program will need the
following components:
1. A variable representing the maximum size of the queue (how many items can be stored
in the queue at one time). This value should have a default value of 10.
2. A list type variable, which is used to store all of the data in the queue.
3. An enqueue function, which takes a single input value. If there is room in the queue (i.e.,
the current size is less than the maximum size), the value will be added to the end of the
queue and the function will return True. If there is no room in the queue, the function will
return False.
4. A dequeue function, which has no inputs. If the queue has any items in it, this function
will remove and return the first item (i.e., from the front of the queue). If the queue does
not have any items in it, the function should return None. In this case, None is the
specific Python value representing nothing, not the string value “None”.
5. A peek function, which has no inputs. If the queue has any items in it, this function will
return the value of the first item in the queue but leave that item in the queue (different
from the dequeue function). If the queue does not have any items in it, the function
should return None. In this case, None is the specific Python value representing nothing,
not the string value “None”.
6. An isempty function, which takes no inputs. This function should return True if the
queue is empty (no items) and False otherwise.
7. A getlist function, which has no inputs. This function will return the list that stores the
queue data. This function can be used to print the queue contents using print(getlist()).
8. A multienqueue function, which takes a single list type input argument. This function
should add as many of the items from the input list to the queue (i.e., keep adding until
COMP 1005/1405 – S17 – A4 Due Sunday, June 4 at 11:55 PM
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the queue is full or all items have been added) and return the number of items that were
added successfully.
9. A multidequeue function, which takes a single integer input value N. This function
should attempt to dequeue up to N items from the queue and return a new list containing
all items removed (note: this may be less than N if the queue has become empty).
Save your queue function code into a file called queue.py that only includes the functions
and necessary variables (i.e., no testing code) and add it to your submission zip. You can
test your code by importing your queue.py file as a module into a separate Python code file
and calling the functions with specific values. To aid in your testing, a queuetester.py file has
been included on cuLearn. If you run this Python file within the same directory as your
queue.py file, it will perform a number of the queue operations. The testing program will also
print out the expected values so you can verify that your queue functions are working
correctly. You should perform additional tests to further verify your functions’ correctness.
Problem 2 (Start and End Words)
For the purposes of this question, we will define a word as ending a sentence if that word is
immediately followed by a period. For example, in the text “This is a sentence. The last
sentence had four words.”, the ending words are ‘sentence’ and ‘words’. In a similar fashion,
we will define the starting word of a sentence as any word that is preceded by the end of a
sentence. The starting words from the previous example text would be “The”. You do not
need to consider the first word of the text as a starting word. Write a program that has:
1. A startwords function that takes a single string argument. This function must return
a list of all sentence starting words that appear in the given string. There should be
no duplicate entries in the returned list.
2. An endwords function that takes a single string argument. This functioin must return
a list of all sentence ending words that appear in the given string. There should be no
duplicate entries in the returned list and the periods should not be included in the
ending words.
Save your function code into a file called sentences.py that only includes the
functions and necessary variables (i.e., no testing code) and add it to your submission
zip. You can test this program in a similar fashion to the program from Problem 1. A
sentencetester.py file has also been added to cuLearn to aid in testing.
Your zip file should contain your queue.py, and sentences.py files.
Submit your assignment4.zip file to cuLearn.
Make sure you download the zip after submitting and verify the file contents.