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.

Credits 4
Section A, B
Semester Spring 2018
Date Time, Location
  • Section A: MWF 9:00 - 9:50 am, Davis 117
  • Section B: MWF 10:00 - 10:50 pm, Davis 117
Lecture Instructor Ying Li
Office: Davis 115
Phone: (207)-859-5852
Office hours: MTWR 2:00 - 4:00 pm. If the door is open and I'm not already in a meeting, feel free to come in.
Lab Instructor Bruce Maxwell
Office: Davis 112
Phone: (207)-859-5854
Office hours: Knock. M 10pm-late, R 7:30pm-late. Any time my door is open.
Evening TAs Location: Davis 102
Date, Time TA
Sunday, 4:00 - 7:00 Melody Mao
Sunday, 7:00 - 10:00 Tracy Quan, Michael Thurston
Monday, 4:00 - 7:00 Brandon Troisi
Monday, 7:00 - 10:00 Hannah Bossi, Matt Martin, Adam Carlson
Prerequisite CS 151, CS152, or equivalent
Course Goals
  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 implementation 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 result of their work and describe an algorithm.
  • Weekly homework: Assigned usually every Wednesday. The deadline is Friday at the beginning of the class.
  • Programming Projects: Assigned usually every Monday. The usual deadline is the following Monday midnight.
Submission, Late Policy

The homework deadline is a hard deadline. Since we will usually discuss the solution in class, late submission will not be accepted. Homework will be graded in a binary fashion: if you hand in a reasonable attempt, you get a 1, otherwise a 0.

Please send me your homework via email, and make sure the title of your email follows this format CS231 Spring2018 HW# -- Your Name (e.g., CS231 Spring2018 HW1 -- Ying Li).

Projects are graded based on a 30 point scale. Late projects will receive a maximum score of 26/30, so handing in something on the due date is generally better than handing in a complete assignment late.

As you all have busy schedules, each student is allowed to have one free four-day extension that can be used at your discretion over the course of the semester, excepting only the final project. That means you may choose to hand in one project on Friday instead of Monday. Please email both professors to let them know you are taking your extension before the deadline.

  • Weekly quizzes: There will be a 5-10 minute quiz every Friday. The lowest quiz will be dropped.
  • Final exam: It will be on Saturday, May 19.
Class Participation You are expected to attend every class. Discussion is a vital part of the learning experience. Good class discussion needs your contribution. If you must miss a class, you are responsible for making up the material covered in that lecture.
Grading The course grade will be determined as follows:
  • Projects: 45%
  • Weekly Quizzes: 25%
  • Final Exam: 20%
  • Weekly Homework: 5%
  • Class Participation: 5%

You may choose from any number of Data Structures with Java textbooks that are available, however, we do not require any specific text. There are also lots of on-line resources available.

Links to free online data structures textbooks:
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 homework and programming 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, if you see more than 10 lines of someone else's code, then you should cite them. You will not be penalized for working together.
  • 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 be talking English with one another, not program languages.
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

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