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  • This website is under construction and is still being updated for 2022.
  • Each student in this course is expected to abide by the Cornell University Code of Academic Integrity. Any work submitted by a student in this course for academic credit must be the student’s own work.


Intermediate programming in a high-level language and introduction to computer science. Topics include object-oriented programming (classes, objects, subclasses, types), graphical user interfaces, algorithm analysis (asymptotic complexity, “big O” notation), recursion, testing, program correctness and loop invariants, searching/sorting, data structures (lists, trees, stacks, queues, heaps, search trees, hash tables, graphs), and graph algorithms. Java is the principal programming language.

Course Information

Time & Place


  • Tuesdays and Thursdays, 10:10-11:00am, Statler Auditorium

You are expected to attend all lectures and one discussion each week. Cornell guidelines related to health must be followed.

  • Prelim 1: September 20, 5:30-7:00pm (KND 116, RCK 201) or 7:30-9:00pm (BLY 101)
  • Prelim 2: November 15, 5:30-7:00pm (KND 116) or 7:30-9:00pm (BLY 101)
  • Final: December 14, 7:00-9:30pm (TBD)

Course Staff

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TA office hours are held in Rhodes 405 unless otherwise specified.

Teaching Assistants

DIS201Siqiu Yaosy657
DIS202Dasha Griffiths & Diego Virtuedkg39, dtv25
DIS203Sowmya Dharanipragadasjd266
DIS204Emily Yu & Tomer Shamiresy34, tys7
DIS205Benjamin Carletonbc534
DIS206Siqiu Yaosy657
DIS207Meghana Pothineni & Sowmya Dharanipragadamp894, sjd266
DIS208Kyra Lee & Mena Attiakl627, mma89
DIS209Nhan Tran & Angela Chaont322, ac2323
DIS210Benjamin Carleton & Mina Prapakamolbc534, jp889
DIS211Maya Leong & Amy Cuimfl74, yc2478
DIS212Amy Huang & Timur Beletskiiach243, tab282
DIS213Xiangzhi Liuxl829
DIS214Zhongqian Lizl469
DIS215Tanvi Namjoshitkn24
DIS216Zhaoyu Wangzw577


Very good performance in CS 1110 or an equivalent course, or permission of the instructor. If you are unsure whether CS 2110 or CS 2112 is the right course for you, please talk to the instructor of either course. Both courses cover similar material and satisfy the same requirements, but CS 2112 covers material in more depth and has more challenging assignments.


You are expected to read the course notes posted on the web site. These will often contain more detail than what was presented in lecture.

Other Sources

These titles will be on reserve in the Engineering Library (@ Uris Library).


We will be using Ed as an online discussion forum. You are encouraged to post any questions you might have about the course material. The course staff monitor the forum fairly closely and you will usually get a quick response. If you know the answer to a question, you are encouraged to post it, but please avoid giving away any hints on the homework or posting any part of a solution—this is considered a violation of academic integrity.

By default, your posts are visible to the course staff and other students, and you should prefer this mode so that others can benefit from your question and the answer. However, you can post privately so that only the course staff can see your question, and you should do so if your post might reveal information about a solution to a homework problem. If you post privately, we reserve the right to make your post public if we think the class will benefit. You can also post anonymously if you wish not to reveal your identity.

The discussion forum is the most effective way to communicate with the staff and is the preferred mode of interaction. Please reserve email for urgent or confidential matters. Free-ranging technical discussions are especially encouraged. Broadcast messages from the course staff to students will be sent using Ed and all course announcements will be posted there, so check in often.

See our office hours and consulting section below for additional notes regarding Ed Discussion.


We will be using the course management system CMSX for managing assignments, exams, and grades. Everyone who preregistered for the course should be entered, but if you did not preregister, you are probably missing. Please login here and check whether you exist. There will be a list of courses you are registered for, and CS 2110 should be one of them. If not, please send your full name and Cornell netId to the Administrative Assistant so that you can be registered.

You can check your grades, submit homework, and request regrades in CMSX. Please check your grades regularly to make sure we are recording things properly. The system also provides some grading statistics. There is a help page with instructions.

Do not repost course materials released on CMSX publicly. These materials are intellectual property of Cornell and are meant for participants in the course. They are not free to the public.

Announcements and Handouts

Announcements will be posted to Ed. Homework and exam solutions will be available in CMSX. Check frequently for new postings.

Assignments & Exams

Unless otherwise specified, assignments may be turned in late with a penalty of 10% per day, up to 4 days late. Extensions may be granted in case of illness or other acceptable excuse; please contact the course instructor. Extension requests that arrive just before the deadline are less likely to be granted than extension requests that are made in advance. Start early on assignment so you have time to complete it despite the inevitable conflict with coursework from other classes. In addition, students have 4 slip days that they can use during the semester across all assignments. Unless otherwise specified, each assignment may use up to 3 slip days. Using a slip day removes the late penalty. Slip days will be used up automatically.

There will be one 1½-hour evening prelim and a 2½-hour final exam. Please check the schedule page for times and locations.

Your final grade will be based on your assignment and exam scores according to the following weights:

  Lecture (iClicker)2.5%
  Discussion (cooperative exercises)2%
  Course evaluation0.5%
  Assignment 13%
  Assignment 24%
  Assignment 34%
  Assignment 45%
  Assignment 56%
  Assignment 66%
  Assignment 77%
Prelim 110%
Prelim 215%

Perfect attendance is not required to receive full participation credit. Responding to at least 3/4 of lecture questions and submiting at least 3/4 of discussion activities is sufficient. This provides flexibility to miss an occasional class for illness or a conflicting obligation without worrying about the impact on your grade. There are no make-up opportunities for participation credit; if you think you need to miss more than 25% of class meetings for legitimate reasons, discuss your situation with an instructor or advisor.

You will have two attempts to respond to each weekly quiz (note that the questions may be slightly different), and we will take your highest score. The quizzes are open-note, but they are timed and must be completed individually. Late submissions are not accepted, as questions will be discussed in discussion sections the following day. We will drop your lowest quiz score automatically to accommodate unexpected circumstances.


Graded homework will be available on CMSX, and graded exams will be available on Gradescope. If you identify an error in how the rubric was applied to your assignment, you may submit a regrade request during the allowed window (typically within 1 week of an assignment being returned and within 2 days of an exam being returned). Errors not identified during the request window will not be corrected.

Regrade requests are submitted electronically in both CMSX and Gradescope. When submitting a request, explain precisely why the deduction does not apply to your solution. When evaluating a request, staff will review the entire question for grading accuracy and consistency, so it is possible for your score to decrease if errors in your favor are identified.

Academic Integrity

Each student in this course is expected to abide by the Cornell University Code of Academic Integrity. Any work submitted by a student in this course for academic credit must be the student’s own work.

The utmost level of academic integrity is expected of all students. Under no circumstances may you submit work done with or by someone else under your own name or share detailed proofs or code with anyone else except your partner. However, discussions about general techniques or the requirements of the assignment are permissible.

You must cite all sources, including Internet sources. You must acknowledge by name anyone whom you consulted (excluding course staff). You may not give nor receive assistance from anyone else during an exam. You may not give any hints or post any material that might be part of a solution publicly on Ed. If your question necessarily includes such material, post privately.

If you are unsure about what is permissible and what is not, please ask on Ed.

Academic Integrity Resources:

Special Needs

We will provide appropriate accommodation for students with special needs or disabilities. Requests for accommodation are to be made during the first three weeks of the semester and must be accompanied by official documentation. Please register with Student Disability Services in 110 Ho Plaza (Cornell Health Building), Level 5 to document your eligibility.

Community of learning

We aim to create an inclusive learning environment where diversity and individual differences are respected and appreciated, and we expect students in this class to demonstrate diligence in understanding how others’ perspectives may be different from their own. Behaviors that contribute positively to our community of learning include:

  • • Recognize that everyone is starting from different bases of knowledge. Be respectful and constructive when pointing out mistakes.
  • • Listen to one another and, especially during group work, actively encourage everyone to contribute.
  • • Help build a lively and active online learning environment. Ask and answer questions on our discussion board, always remembering to be respectful and constructive.

Copyright notice

All materials distributed in this course are copyrighted and may not be distributed further (unless otherwise indicated). They are intended for your sole use and may not be reposted on any public or private website or by any other sharing method (e.g. fraternity exam files). Public availability does not imply permission to redistribute, and materials on CMSX or Canvas are not even public to begin with.

You hold the copyright on original work you create for this course. But note that assignments include significant “skeleton” code authored by the course staff. Therefore, it is generally not permissible to share code for completed assignments. If you want to showcase your new skills in a portfolio, get creative and apply them in a novel setting.

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Course Schedule

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Course notes

Course notes for individual lectures and recitations can be found on the course schedule. The notes are also available as a single printable document.


Java is one of the most widely used object-oriented programming languages, and programming skill in the Java language is in high demand. Nevertheless, this is not a course about Java. Java is simply a good vehicle for explaining many of the ideas on data structures, algorithms, and software engineering that will be covered in the course. Most of the ideas you will be exposed to in this course, and the skills you will develop, will transfer to other programming languages.

Online Resources

Brushing Up

Review the introductory chapters in the textbook and the Java reference books listed on the course info page. For students with C++ experience, check out this Wikipedia page comparing C++ with Java.

Java version

We will be using the Java 17 Standard Edition (Java SE 17) platform, which consists of the Java Development Kit (JDK) and the Java Runtime Environment (JRE). If you are using an earlier version of Java, please upgrade.

To find out which version of the JRE you are running, open a console window (in Windows, right click the Start button and choose Windows PowerShell, and in Mac OS, Applications > Utilities > Terminal) and type java -version at the command prompt:

$ java -version
java version "11.0.4" 2019-07-16 LTS
Java(TM) SE Runtime Environment 18.9 (build 11.0.4+10-LTS)
Java HotSpot(TM) 64-Bit Server VM 18.9 (build 11.0.4+10-LTS, mixed mode)

This says I have version 11 installed.

If you are on a PC running Windows and have never installed a version of the Java Development Kit (JDK) on your machine, you probably don't have it. If you are on a Mac, you probably do. To find out, type javac -version:

$ javac -version
javac 11.0.4

If you get an error message or the version is earlier than 17, you must (re)install the JDK.

We recommend completely uninstalling any prior versions of the JRE or JDK before installing the latest one, to prevent problems later in the semester.

Installing the JDK

The JDK is already installed in CIT and ACCEL labs. However, installing it own your own machine will greatly facilitate your work.

To download the JDK, visit Oracle's Java web site and download and install the appropriate version of the JDK for your platform.

Compiling and Running from the Command Line

Compiling:  Say your main class is MyProgram and it is contained in the source file MyProgram.java. If it is not in a package, navigate to the folder containing MyProgram.java and type javac MyProgram.java. If it is in a package (say myPackage), the source should be in a folder called myPackage. Navigate to the folder containing myPackage and type javac myPackage/MyProgram.java.

Running:  From the same folder you compiled from, type java MyProgram <program arguments> if it is not in a package, and java myPackage.MyProgram <program arguments> if it is.

Specifying a Classpath:  Sometimes you may need to inform Java where to find auxiliary classes. You can do this with the -cp option to the java command. Supply a sequence of folders telling Java where to look for classes, separated by : (Mac) or ; (Windows).

Local Software

Some Java libraries have been developed for use in CS 2110 and CS 2112 assignments. Feel free to use them.

EasyIO: Support for easy console input and output, and for scanning input from a file or string (like java.util.Scanner, but more powerful). [ doc | jar | source ]

Maybe is a better version of the Option pattern, developed for the CMSX project. The Option pattern is provided by Java in the class java.util.Optional, but Maybe throws a checked exception, which makes it both more foolproof and more efficient. [ doc | jar | source ]

cs2110: Various types of queues, including a priority queue supporting in situ adjustment of priorities; a DelimitedStringBuilder similar to one found in OCaml; a module that runs an external script that takes a string on stdin and writes a string to stdout; and a module for easy access to a text resource file. [ doc | jar | source ]


IDE stands for integrated development environment. The use of an IDE is the best way to develop Java programs. IDEs provide many valuable aids such as syntax checking, debugging, and refactoring that can save you a lot of effort.

There are many good IDEs. We recommend IntelliJ, but you may use any one that you like, or none at all. IntelliJ is installed in all the labs. Early recitation sections will get you started with IntelliJ if you are not familiar with an IDE.

Here are some links:

You should follow the 2110 style guide for naming conventions and code format. IntelliJ users can download and install the IntelliJ style template used by the course staff. A legacy Eclipse style template is also available.

Computer Labs

CIT Labs

Cornell Information Technologies (CIT) runs several computer labs across campus for all members of the Cornell community. The JDK and Eclipse are installed on these machines. Check here for locations and times of operation.


You can also find the course software in the Academic Computing Center (ACCEL), located in the Engineering Library in Carpenter Hall. Any CS student may register for an account.

Support Services

Other Support Services

Registrar's Office General services for the Cornell community.
Engineering College Support services for Engineering students.
Arts College Support services for Arts students.
CIT Services offered by Cornell Information Technologies (CIT), including computer training.
Cornell Health The Cornell University Health Service Center. For all health related concerns and counseling services.
Learning Styles Not everyone learns the same way. If you are curious about how you learn, check out this collection.


All source code will be available on CMSX.

Assignment 1 Java warm-up
Assignment 2 CMSμ
Assignment 3 CSV Join
Assignment 4 PhD Genealogy Tree
Assignment 5 Game Search and Hash Tables (JavaDoc)
Assignment 6 Click-a-Dot (JavaDoc)
Assignment 7 McDiver

Other resources for programming assignments:

  • Nothing yet.