Spring 2023
| CRN | Lecture (Carver 103) | Lab Time | Lab Location | Lab TA |
|---|---|---|---|---|
| 20300 | MWF 9:00–9:50am | T 10:00–11:50am | CF 165 | Josh |
| 21235 | MWF 9:00–9:50am | T 12:00–1:50pm | CF 165 | Josh |
| 21715 | MWF 10:00–10:50am | W 8:00–9:50am | CF 165 | Josh |
| 21716 | MWF 10:00–10:50am | W 12:00–1:50pm | CF 164 | Angus |
Design and implementation of hash tables, general trees, search trees, balanced trees and graphs. Comparison of sorting algorithms. Demonstration of the use of data structures in various applications. Evaluation of the best data structure for a particular task. Programming is required in implementation of concepts.
At the end of this course, students will have:
The goal of this course is to round out your knowledge of the fundamental data structures and algorithms that comprise the basic toolbox of a computer scientist or software developer. Along the way, we’ll encounter and develop the following big ideas that permeate many more advanced subfields of computer science:
By the end of this course, students should be able to:
The following texts may serve as useful references, but are not required:
Building Java Programs: A Back to Basics Approach, 5th edition, by Reges and Stepp (ISBN 978-0135471944).
If you already have this book from CSCI 145, it provides an excellent introduction to Java and serves as a good resource for programming basics. It covers some, but not all of the material for CSCI 241 and would be most useful if you need to shore up material covered in CSCI 145.
Introduction to Algorithms, 4th edition, by Cormen, Leiserson, Rivest, and Stein (ISBN 978-0262046305).
This book covers the CSCI 241 material and beyond at a more advanced level; you will need this book for CSCI 305 and CSCI 405, and it is an excellent resource on algorithms and advanced data structures.
In both cases, the specific edition of the book is not important significant for purposes of this class. If you’re getting CLRS with the intent to use it later, you may want to go with the latest edition.
Grades will be calculated as a weighted average of scores on the following course components, each of which is described in more detail below:
In this class we follow the notational convention that a range of
integers denoted a..b describes the range beginning at (and
including) a up to but not including b (this is consistent with
Python’s range function). For example, 1..4
describes the range including 1, 2, and 3 but not 4. The
floor function truncates the decimal part of a
floating-point value (that is, rounds down to the nearest smaller
integer). Final letter grades will be assigned as follows.
floor(%) |
Grade |
|---|---|
| ≥ 90 | A range |
| 80..90 | B range |
| 70..80 | C range |
| 60..70 | D |
| 0..60 | F |
The calculated raw percentages may be curved nonlinearly at the instructor’s discretion, but any such curve used will not reduce anyone’s grade. “+” or “-” cutoffs will be decided at the instructor’s discretion.
Four programming assignments will be given to provide practice implementing the major concepts covered in the course:
You may resubmit any programming assignment (i.e., A1, A2, A3, A4) within two weeks of when grades are released (or the day of the final exam, whichever is earlier) to earn back up to half of the unit test points you lost. Only unit test points can be earned back. When you resubmit, you must send me an email to request that your submission be regraded for partial credit back.
In any of the programming assignments where unit tests are provided, you can earn extra credit if you discover a gap in my test suite. Specifically, if you discover that your implementation passes the provided test cases up to and including the tests for a given method but that method still has a bug, you can earn up to 3 points of extra credit for providing a correct test case that catches the bug.
If you find such a bug and wish to earn extra credit:
testing branch in your repository
(git checkout -b testing).You can send your test case in anytime starting before the assignment is completed (create your testing branch then simply swich back to master, fix the bug, and continue on) up until 5pm on the last day of classes.
Weekly labs will provide hands-on experience with auxiliary topics as well as time for work on programming assignments with the TA available to answer questions during the lab period. To get full credit for a lab activity, you must both attend lab and hand in the deliverable by the deadline, which will typically be 10:00pm on the Sunday following the lab period. Attending a lab section other than the one you are registered for requires permission from both me and both lab TAs. If you do not attend lab but do submit the deliverable on time you will receive half credit (i.e., your score will be multiplied by 0.5). This non-attendance penalty is automatically waived for one lab; if you have a legitimate reason for missing additional labs, contact me ahead of time. No late lab submissions will be accepted.
Weekly quizzes will be given most Fridays after the first week, covering material up to but not including that day’s topic. Quizzes usually focus on material from the preceeding Friday, Monday, and Wednesday’s classes. I have a strict policy against makeup quizzes, but your lowest quiz grade will be dropped. If special circumstances cause you to miss taking more than one quiz, please talk to me ahead of time.
The midterm exam will be given on paper in class on May 5th and will cover material through Lecture 13 (May 1st). You will be allowed to use one double-sided 8.5x11 sheet of handwritten notes.
The final exams are scheduled as follows:
The final exam will be cumulative, but slightly more emphasis will be placed on material covered since the midterm. You will be allowed to use two double-sided 8.5x11 sheets of handwritten notes. Per the University Academic Policies, a student who fails to take a final examination without making prior arrangements acceptable to the instructor receives a failing grade for the course.
I do not release final exams or final exam grades. This means that at the end of the quarter, your score on Canvas will not reflect your final grade in the course. If you wish to see your final exam, you can review your final exam in-person in my office starting at the beginning of the following quarter by visiting my office hours or emailing me to make an appointment.
Before each class, you will watch up to three short videos and work
through a set of Exercises that test your understanding
of the material from the videos. You will submit your individual
solutions to Canvas to the assignment titled “E##I”
(I for Individual; ## is the
lecture number). Individual solutions will be graded for
completion. Your lowest three E##I scores
will be dropped when calculating this portion of the grade. The
individual solution sets constitute 5% of the total grade weight.
In class, your team will get together and collaboratively write a
solution set for the exercises. The group’s solution set will be handed
in during class and graded for correctness. Grades for
team solutions will be in a Canvas assignment titled E##T
(T for Team). Your lowest three
E##T scores will be dropped when calculating this portion
of the grade. The team solution sets constitute 10% of the total grade
weight.
Note that the Exercises to be completed before lecture are distinct from Problems, which you will work on in class after finishing your collective Exercise solution set. Grades will be based only on Exercises, not Problems - the Problems are designed to challenge you, so I do not expect that all groups will be able to finish all of them. Some class time will be spent in groups working on Problems, while some will be spent discussing Exercise and Problem solutions.
The groupwork-heavy design of this course is motivated by research that shows that peer instruction is an effective teaching methodology that improves student learning outcomes. If you are absent or disruptive, this is detrimental not only to your own learning, but to your peers’ as well. To get credit for the team-based submission, you must be present and engaged for the entire class period. By writing your name on an Exercise Solution Set in class, you are certifying that you are present for the whole class period and actively participating during group work. If you list your name after arriving late or before leaving early, this can be considered a breach of academic honesty. If you arrive late or leave early, you may participate in group work as usual, but you will leave your name off the Solution Set sheet and you will be considered absent for grading purposes.
If you are stuck, struggling, or need help on any aspect of the course, you have several avenues for seeking help:
q-and-a channel on the Discord
server.The Computer Science department has Faculty community ambassadors. The role of these ambassadors is to hear concerns, feedback, or questions from students, faculty and staff, especially (but not limited to) those related to equity, inclusion and diversity issues. We hope that the Community Ambassadors can advise and also guide people to college, university or external resources.
Our current Faculty Community Ambassadors are Yasmine Elglaly and myself (Scott Wehrwein). You can find more information on Commnity Ambassadors and contact details for both at the following link: https://cs.wwu.edu/diversity-equity-inclusion.
As a reminder, the following University resources are always available:
The Schedule section of this page will be
kept up-to-date as the quarter progresses with topics, links to all
lecture materials (videos, slides, exercises, problems, and readings),
as well as links to assignment and lab handouts. I suggest bookmarking
this page (including the #schedule at the end will link you
straight to that part of the page); if you forget the URL and need to
find your way back here, you can find the link on the Syllabus page in
Canvas.
The CS department maintains a set of Computer Science computer labs separate from the general university labs. These systems are all set up with the software that you need to complete the work for this class.
CS Accounts
To log into the machines in these
labs, you will need a separate Computer Science account, which you’ll
already have if you’ve previously taken another CS course at Western. If
you haven’t taken a CS course at Western before, this will be created
for you in the first week of classes. Your username will be the same as
your WWU username, but you will need to activate your account and set a
new password by visiting http://password.cs.wwu.edu. Note
that you’ll need to do this before your first lab, since you’ll
be unable to log into the computers to access a web browser until you’ve
done this.
Lab Locations and Access
The following rooms in
Communications Facility are CS Department labs: 162, 164, 165, 167, 405,
418, 420. These labs are open to all CS students (that’s you!) any time
except when scheduled for a class or other activity. The complete of CS
labs and their schedules can be found on the CS
Support documentation. CF 405 is never booked, so it’s always
available. Labs are open 24/7, although the building locks at 11pm so
you won’t be able to enter later than that.
Using Labs Remotely
Please see the Remote Access Instructions for details on how to work remotely in the CS lab environment.
We will use Canvas for announcements, assignment invitation links, grades, and some other logistics. Lab and assignment writeups, lecture materials, readings, etc. will all be linked from the course webpage. Numerical grades will be entered into Canvas to track your scores for assignments in the course, but feedback on your assignments will be provided via Gradescope (quizzes and exams) or Git (assignments and labs), as described in the sections below.
Quizzes and exams will be graded and returned to you via an online tool called Gradescope. You will receive an email around the time of the first quiz with instructions on how to set a password for the account that has been created for you. Logging in for the first time is the same process as resetting your password - begin by clicking the “forgot password” link. Thereafter, you can access graded quizzes and exams by logging into your account on http://www.gradescope.com.
Labs and assignments will be completed using Git repositories hosted by GitHub and orchestrated by GitHub classroom. For each assignment and lab, you will find an invitation link in the assignment page on Canvas. This link will create your private repository where you will complete the assignment in a local copy of the repo, and submit your code by pushing your final changes to GitHub. To complete your submission, you will also fill out a Canvas survey letting me know how many hours you spent on the assignment.
To grade your assignments (and in some cases, labs) Github Classroom
automatically creates a feedback branch in your repository
and a pull request to merge all the commits you’ve made to
master into the feedback branch. This allows
us to use Github’s code review tools to give you feedback directly in
your repository. To access your feedback, go to your repository on
github.com click “Pull Requests” from among the tabs across
the top, then click “Feedback” in the list on that page. You should see
a log of comments and feedback, including line-by-line comments if we’ve
left any.
For the assignments with unit tests, we’ve also set up Github Classroom to automatically run your code on those tests every time you push your changes to github. This is a form of continuous integration testing, which is a fancy term for “run ALL the tests every time you change anything”. You’ll probably get emails telling you the outcome of the checks (which will only be successful if you pass all tests); I think there’s a way to unsubscribe from them, or you can use an email filter to keep your inbox clutter to a minimum.
The course Discord server is a good way to interact with your
classmates and ask questions. You can find the server invite link on the
Syllabus page on Canvas. I try to check the q-and-a channel
regularly and answer questions when possible, but I also hope that
classmates will be able to step in and answer questions before I get to
them.
Discord is not the place to get help that requires viewing of code, nor is it the place for “official” course communication. A couple points of Discord etiquette that I will require for this class:
Your server nickname in our Discord server must be your first (or preferred) and last name (you may also include pronouns if you like). I will warn and then kick any server members whose nicknames do not follow this policy. To set your server nickname, click the server name in the top left, then Edit Server Profile, then set your nickname in the Server Nickname field. Your avatar image must also be appropriate for a professional setting.
I do not accept direct messages on Discord; please use email instead.
Unless you are raising a time-sensitive issue that affects multiple students (e.g., the link to the lab handout for today’s lab is broken), please do not @mention me on Discord.
I will make all course-related announcements either in class or on Canvas. In-class announcements will be posted on the Schedule table on the course webpage. It is your responsibility to make sure that you see Canvas announcements promptly and check the in-class announcements if you miss class. Canvas should be configured to send you an email notification by default, but if you are unsure, please come see me in office hours.
Email is the best way to get in touch with me. I do my best to check email regularly and respond when I can, but I am not able to be instantly responsive all the time. If you have something time-sensitive, email is the medium that I am most likely to see first. You can use Canvas messages as an alternative; these simply go to my email.
The policies for this course have “grace” built in for most
categories of assignments: you have slip days for assignments, your
lowest quiz gets dropped, you can miss one lab without an attendance
penalty, and you can miss up to three E##I and three
E##T submissions without penalty.
If any of the above forms of “grace” apply to your situation, you do not need to contact me: the grace policies are applied automatically. If you have used up all of a certain kind of grace and extenuating circumstances will cause you to go beyond the allowed grace, please contact me by email or in person to explain your situation.
I do not read Canvas submission comments, so please do not use them. If you have a message for me and/or the TAs, please use email instead.
Many quick questions can be resolved in a timely fashion by talking to me after class instead of using email or waiting for office hours. I will be available in the 10 minutes following lecture, so please feel free to use this time.
I take student feedback seriously. I appreciate any feedback you’re willing to give, and I will do my best to act on constructive feedback when possible. I will solicit feedback through surveys periodically throughout the course, but you are welcome and encouraged to provide feedback anytime in my office hours, by email, or if you desire anonymity you can fill out this Google Form.
This table contains a schedule of topics and links to all course materials. Rows in the future should be considered tentative and subject to change.
| Date | # | Videos | Slides | E/P | Topic | Assigned/Due | References |
|---|---|---|---|---|---|---|---|
| 3/29 (0) | 0 | intro | Problems | Intro, logistics | |||
| 3/31 | 1 | A: 5:18
B: 13:14 C: 9:21 |
A B C |
Exercises Problems |
Tools for algorithms, Searching announcements How to succeed |
RS 13.2-13.3, CLRS 2.1-2.2 | |
| 4/3 (1) | 2 | A: 9:42
B: 10:18 C: 19:13 |
A B C |
Exercises Problems |
Runtime analysis announcements |
Lab 1: Git, Gradle |
RS 13.2-13.3, CLRS 2.2 |
| 4/5 | 3 | A: 9:45
B: 10:26 C: 15:02 |
A B C |
Exercises Problems |
Insertion and selection sort announcements |
A1 out | RS 13.2-13.3, CLRS 2.1-2.2 |
| 4/7 | 4 | A: 4:19
B: 8:20 C: 5:14 |
A B C |
Exercises Problems |
Recursion announcements |
Quiz 1 | Tutorial:
Method execution RS 12.1-12.3 |
| 4/10 (2) | 5 | A: 6:59 B: 7:15 C: 8:24 |
A B C |
Exercises Problems |
MergeSort announcements |
Lab 2: Testing |
RS 13.4, CLRS 2.3 |
| 4/12 | 6 | A: 10:42 B: 5:27 C: 6:14 |
A B C |
Exercises Problems |
Quicksort, Stability, Space Complexity announcements |
CLRS 7.1 |
|
| 4/14 | 7 | A: 13:26 | A | Exercises Problems |
Comparison Sorts Radix Sort announcements academic honesty activity |
Quiz 2 | CLRS 8.2-8.4 |
| 4/17 (3) | 8 | A: 7:50 B: 4:59 C: 6:10 |
A B C |
Exercises Problems |
Trees, Traversals, Recursion on trees announcements |
Lab 3: Recursion |
RS 17.1-17.3 |
| 4/19 | 9 | A: 9:52 B: 8:21 C: 6:44 |
A B C |
Exercises Problems |
Binary Search Trees announcements |
CLRS 12.1-12.3 RS 17.4 |
|
| 4/21 | 10 | A: 9:54 B: 5:01 C: 9:26 |
A B C |
Exercises Problems |
Generics Tree Rotations announcements |
A1 due Quiz 3 |
CLRS 13.2 |
| 4/24 (4) | 11 | A: 6:20 B: 9:19 |
A B |
Exercises Problems |
AVL Trees announcements |
Lab 4: AList A2 out |
Eric Alexander’s AVL Tree Notes |
| 4/26 | Buffer day - Partition Code Review! | ||||||
| 4/28 | 12 | A: 4:31 B: 8:42 C: 3:39 |
A B C |
Exercises Problems |
Heaps announcements |
Quiz 4 | RS 18.2; CLRS 6.1-6.3 |
| 5/1 (5) | 13 | (None) | (none) | (No Exercises) Problems |
Heapsort | Lab: Midterm Review |
RS 18.2; CLRS 6.1-6.3 |
| 5/3 | Buffer day | ||||||
| 5/5 | Midterm Exam | ||||||
| 5/8 (6) | 14 | A: 3:57 B: 6:23 C: 4:05 |
A B C |
Exercises Problems |
Hashing 1 announcements |
Lab 5: Hash functions A2 Due A3 out |
RS 18.1; CLRS 11.1-3 |
| 5/10 | 15 | A: 5:23 B: 3:45 C: 4:16 |
A B C |
Exercises Problems |
Hashing 2 announcements |
CLRS 11.3-4 | |
| 5/12 | 16 | A: 6:44 B: 4:35 C: 2:13 |
A B C |
Exercises Problems |
Graphs: definition, representation announcements |
Quiz 5 | CLRS 22.1-2 |
| 5/15 (7) | 17 | A: 6:12 B: 3:05 C: 2:37 L17P |
A B C |
Exercises Problems |
Graph traversals announcements |
Lab 6: Connected Components |
CLRS 22.3 |
| 5/17 | 18 | A: 12:37 B: 3:45 C: 3:17 |
A B C |
Exercises Problems |
Dijkstra’s algorithm announcements |
CLRS 24.3 | |
| 5/19 | 19 | A: 6:40 B: 10:42 C: 12:21 |
A B C |
Exercises Problems |
Tries announcements |
Quiz 6 | |
| 5/22 (8) | 20 | A: 9:14 B: 7:34 |
A B |
Exercises Start on Lab 7 |
Huffman Coding Trees announcements |
Lab 7: Huffman Coding A3 due A4 out |
CLRS 16.3 |
| 5/24 | A: 9:43 | A | (No Exercises) Problem |
Dijkstra: Proof | Quiz 7 | CLRS 24.5 | |
| 5/26 | Problems | Coding Interview Problems | |||||
| 5/29 (9) | No class - Memorial Day | No Lab: Memorial Day A4 due |
|||||
| 5/31 | Ask me anything or no class | ||||||
| 6/2 | Ask me anything or no class | ||||||
| 6/7 (Wednesday) | Final Exam - 9am section 10:30 - 12:30pm |
||||||
| 6/8 (Thursday) | Final Exam - 10am section 10:30 - 12:30pm |
I am committed to maintaining an inclusive, supportive, and professional environment in all academic settings including lectures, labs, and course-related online spaces. Students are expected to live up to the ACM Code of Ethics and Professional Conduct. This is the ethical code adopted by nearly every software professional. Failing to follow the ACM Code of Ethics and Professional Conduct can negatively affect course grades up to and including a failing grade for the course. Conduct is also considered when determining admission to the major.
As described above in the Assessment section, you are expected to attend both class and lab. Up to three absences from class will not affect your grade; additional absences will cause deductions on the in-class portion of your grade. For labs, the 50% absence penalty will be waived for one lab. If you have reasons that you need to miss class or lab beyond these limits, please talk to me about case-by-case exceptions.
You have three “slip days” that you may use at your discretion to submit programming assignments late. Slip days apply only to programming assignments and can not be applied to any other deadline, including labs. You may use slip days one at a time or together - for example, you might submit each of three assignments one day late, or submit one assignment three days late. A slip day moves the deadline by exactly 24 hours from the original deadline; if you go beyond this, you will need to use a second slip day, if available.
After your slip days are exhausted, a penalty of 10% * floor(hours_late/24 + 1) - that is, 10% per day late unless you have made prior arrangements with me.
Submission of assignments is done by (1) pushing your final changes to Github and (2) filling out a Survey quiz on Canvas. To submit late, you don’t need to let me know: simply don’t submit the Canvas survey until you are done. Slip days will be applied automatically based on when you submitted the survey; your grader will note the number of slip days applied in your feedback.
Your programs will be graded on correctness, clarity, and efficiency (in that order).
A correct program is one that always produces the correct output for a given input. Also, a correct program does not produce unintended side-effects. The most effective way to ensure that your program is correct is to test, test, test. Test each component as you introduce it; once you are confident that a component works you can use it in other routines. Try to break your program in testing, and if you succeed, locate the bug and fix it. The better you test your program, the more likely it is to be correct - the more likely it is to be correct, the more likely you’ll earn a good score. Most of your grade will depend on the correctness of your code.
The easier it is to read and maintain your code, the easier it is to locate and remove bugs. Your program should be well organized, appropriately commented, and easy to maintain. To have a well-organized program, design your program thoughtfully and modularly. Think before you code: hacking away blindly leads to ugly, difficult-to-read code. If you do hack away, producing a functional but ugly wall of code, try to clean it up a bit. Make sure that your cleaning does not introduce new bugs.
As for comments, please follow these simple guidelines proposed by Emeritus Professor Osborne:
Your programs should be asymptotically efficient, e.g. checking graph reflexivity should be O(n), insertion into a balanced tree should be O(log n), etc. Do not optimize your code beyond the asymptotic level, as such tweaks are often at the expense of clarity, correctness, or both.
Individual programming assignments are to be completed independently. Students are welcome to discuss assignments with each other on a conceptual level, but each student should be writing their code independently and without direct help from fellow students. Sharing your code with others or looking at someone else’s code is an explicit violation of this collaboration policy. To make sure you are collaborating appropriately, follow these two rules:
Automated tools will be used to check your code for plagiarism at the push of a button. They are not fooled by tricks such as changing variable naming and whitespace: in fact, hiding plagiarism is harder than doing the assignment.
This syllabus is subject to change. Changes, if any, will be announced in class or online. Students will be held responsible for all changes.
All University-wide policies apply to this course, including those outlined at http://syllabi.wwu.edu. These policies cover issues including: