Focuses on the common structures used to store data and the standard algorithms for manipulating them. Standard data structures include lists, stacks, queues, trees, heaps, hash tables, and graphs. Standard algorithms include searching, sorting, and traversals. Along with implementation details, students will learn to analyze the time and space efficiency of algorithms and how to select appropriate data structures and algorithms for a specific application. In homework, labs, and programming projects, students will implement their own data structures and make use of existing libraries to solve a variety of computational problems.

Sections A and B
Semester Spring 2021
Date Time, Location
  • lecture A: M-W-F 9:00 - 9:50 am, online via Zoom
  • lecture B: M-W-F 10:00 - 10:50 am, online via Zoom
  • lab A: M 1:00 - 2:20 pm Davis 102
  • lab B: M 2:30 - 3:50 pm Davis 102
  • lab C: T 1:00 - 2:20 pm online via Zoom
  • lab D: T 2:30 - 3:50 pm Davis 102
Instructor Prof. Dale Skrien
Office: Davis 211 (but I don't use it much)
Office hours (online via Zoom): Monday 6-7pm, Wednesday 1-3pm, Friday 12-2pm
Lab Instructor Prof. Naser Al Madi
Office: Davis 215
Office hours (online via Zoom): Available here
Weekly Course Schedule

The following structure will rarely change.

Day and time Activity
Monday 9:00-9:50 or 10:00-10:50 Problem session
Monday, 11:59 pm Previous week's project due
Wednesday 9:00-9:50 or 10:00-10:50 Problem session
Friday 9:00-9:50 or 10:00-10:50 Problem session
Online quiz assigned
Evening TAs

In order to provide as much help as possible to you as you work on assignments in this course, the CS Department has hired upper-level CS students to work as TAs over Zoom in the evenings. You are strongly encouraged to take advantage of this resource.

Class time problem sessions The lectures will be run in a "flipped" manner. This means that class time will not actually be used for lectures. Instead, lectures that introduce new material will be available as videos for you to watch online or to download and watch at your convenience offline. The class time will be devoted to the following:
  • Answering any questions you have regarding the current project.
  • Discussing the homework assigned for the class.
  • Discussing the video lectures assigned for the class
  • Solving other problems provided by the instructor to reinforce the lecture material.
Course Goals The learning goals for the lecture and lab are the same -- both are meant to work together to accomplish the goals for the course as a whole. They are
  1. Students understand the advantages and disadvantages of fundamental data structures and can implement them using object- oriented design principles.
  2. Students understand, can implement, and can calculate the time and space efficiency of classic search, sort, and traversal algorithms, including the use of big-Oh notation.
  3. Students understand the tradeoffs between different implementations of data structures and algorithms and can make appropriate design decisions based on application data requirements.
  4. Students can use fundamental data structures and algorithms appropriately to solve a variety of computational problems.
  5. Students can communicate the results of their work and describe an algorithm.
Labs and Projects

The work in lab will lead into and be part of the week's project. Labs will also count significantly towards participation.

During each lab, the instructor will not be able to answer questions about any projects until you have completed the tasks for that lab.

Programming projects involve completing more significant programs as well as a writeup describing the work completed in the project.


There will be regular opportunities for you to practice what you have learned and to demonstrate your accomplishments.

The course grade will be determined as follows:

Labs and Projects 45%

Hands-on opportunities to implement and explore concepts from lecture.

Short homework assignments 5% Graded in a binary fashion:
1 if you made a serious attempt
0 otherwise.
Quizzes 25% Short weekly or biweekly online quizzes on Fridays.
Participation 5% I expect you to be an active contributor in the classroom. This requires you to attend both lectures and lab. It is not a problem if you know that you will not be able to attend a lecture or lab, but please email the instructor in advance to let him know.
Online Final Exam 20% A 2-3 hour opportunity at the end of the semester to demonstrate your ability to answer questions about course material.
Daily Homework
  • I will distribute short daily homework assignments after every class on Moodle. They will be due the evening before the next class at 11:59pm. There will be a dropbox on Moodle for you to turn in your homework. Late submissions will not be accepted because I want to review your homework solutions before the next class, where we will discuss the homework.
  • The homeworks themselves may not be worth much of your overall grade, but they help prepare you for the quiz on Friday! Take them and the problems discussed in the problem sessions seriously and you should be well-prepared for the quiz.
  • Homework will be graded in a binary fashion: if you turn in a reasonable attempt, you get a 1, otherwise a 0.
  • I understand that everyone has a bad day or may have to miss a homework assignment due to conflicts, and so, for each student, their 2 homeworks with the lowest grades will be dropped, when computing course grades.
Weekly quizzes
  • There is an approximately 15-minute quiz most Fridays online on Moodle. You will typically have a 12-hour window beginning Friday afternoon to complete the quiz at a time that works best with your schedule.
  • The quizzes let you show me what you have learned. These should be quick and straightforward if you participate in problem sessions, do the assigned homework problems, and review the lecture videos.
  • For each student, their 2 quizzes with the lowest grades will be dropped, just like with homework assignments.
  • In general, there will be no way to make up a quiz missed due to conflicts such as sporting events. Instead, a missed quiz will be counted as one of the 2 quizzes that will be dropped. However, students can request special consideration if they have to miss more than 2 quizzes, for example, due to a documented health issue.
Class Participation
  • You are expected to attend every class and lab. This is important for the overall learning experience and cohesion of the course.
  • If you must miss a class for any reason, please email me in advance. I am happy to work with you.
  • For this course to be truly successful, your presence and participation is important. When you have a question, ask it. It is highly probable that one of your classmates has the same question.
Final Exam

There will be an online final exam during finals week. You will have a 24-hour window in which to take it. There are no make-ups.


It should go without saying that you should back up any files related to this course. If the code you submit to us is somehow lost (through your fault or our fault), I must be able to get another copy from you. I suggest keeping your CS151 labs and projects on Google Drive, Dropbox, or Microsoft OneDrive, but not in a public place. That way, you have a backup stored in the cloud.


There is no required textbook for this course. All lecture materials and code from class will be posted on Moodle.

There are also lots of on-line resources available.
Here are some examples of free online data structures textbooks using Java:
How to succeed

Labs and Projects: Come to lab ready to focus on the new project. Ask the instructor and TAs for help if you need it.

Quizzes: Study for the quizzes by doing the homework, participating in the problem sessions, and watching the lecture videos. As mentioned above, we will drop the lowest two quiz grades. Therefore, if you have to miss a quiz or if you make a silly mistake once or twice, it won't affect your grade.

Short homeworks: Try them. You will receive full credit as long as you make an honest attempt to complete every question and submit your response to the Moodle drop box before the deadline. Please ask or email questions if something isn't clear. There is no credit for late homeworks because we will go over the answers in the next class.

Participation: Speak up in class. Come to office hours. Ask your instructors or TAs for help.

Final Exam: The final exam will be similar to a large set of quizzes (but written from a more holistic perspective) except it may also have a few longer questions. The best way to study for the final exam is to retake all of the old quizzes. Also, read through your notes and all material supplied on the course Moodle page and make sure you understand everything in them.

Collaboration, Academic honesty

Computer science, both academically and professionally, is a collaborative discipline. In any collaboration, however, all parties are expected to make their own contributions and to generously credit the contributions of others. In our class, therefore, collaboration on assignments is encouraged, but you as an individual are responsible for understanding all the material in the assignment and doing your own work. Always strive to do your best, give generous credit to others, start early, and seek help early from both your professors and classmates.

The following rules are intended to help you get the most out of your education and to clarify the line between honest and dishonest work. We reserve the right to ask you to verbally explain the reasoning behind any answer or code that you turn in and to modify your project grade based on your answers. It is vitally important that you turn in work that is your own. We do use automated plagiarism detection software, so please be sure to abide by these, rather minimal, rules. Reports of academic dishonesty are handled by an academic review board and a finding of academic dishonesty may result in significant sanctions. For more details on Colby's Academic Integrity policies and procedures, see

  • If you have had a substantive discussion of any homework or programming solution with a classmate, then be sure to cite them in your write-up. If you are unsure of what constitutes "substantive", then ask me or err on the side of caution. As one rule of thumb, you may discuss your approach to solving a problem, but you must not share or look at another classmate's code or written answers to project questions.
  • You must not copy answers or code from another student either by hand or electronically. Another way to think about it is that you should communicate with one another in natural human sentences, not in lines of code from a programming language.
The Colby Affirmation

Colby College is a community dedicated to learning and committed to the growth and well-being of all its members.

As a community devoted to intellectual growth, we value academic integrity. We agree to take ownership of our academic work, to submit only work that is our own, to fully acknowledge the research and ideas of others in our work, and to abide by the instructions and regulations governing academic work established by the faculty.

As a community built on respect for ourselves, each other, and our physical environment, we recognize the diversity of people who have gathered here and that genuine inclusivity requires active, honest, and compassionate engagement with one another. We agree to respect each other, to honor community expectations, and to comply with College policies.

As a member of this community, I pledge to hold myself and others accountable to these values. More ...

Title IX Statement

Colby College prohibits and will not tolerate sexual misconduct or gender-based discrimination of any kind. Colby is legally obligated to investigate sexual misconduct (including, but not limited to sexual assault and sexual harassment).

If you wish to speak confidentially about an incident of sexual misconduct, please contact Colby Counseling Services (207-859-4490) or the Director of the Gender and Sexual Diversity Program, Emily Schusterbauer (207-859-4093).

Students should be aware that faculty members are considered responsible employees; as such, if you disclose an incident of sexual misconduct to a faculty member, they have an obligation to report it to Colby's Title IX Coordinator. "Disclosure" may include communication in-person, via email/phone/text, or through class assignments.

To learn more about sexual misconduct or report an incident, visit

Religious Holidays Colby College supports the religious practices of students, faculty, and staff. Students are expected to notify their instructors of their intent to fulfill the obligations of their religious tradition well in advance of these days. For this class I ask that you notify me by email at least 14 days in advance of the date in question.

© 2020 Naser Al Madi and Dale Skrien. Page last modified: .