COS 126 Programming Assignments FAQ

We strongly recommend our custom version of IntelliJ. It is the only IDE we support.

Yes. Install (or update to) the COS 126 version, which we refresh every summer.

• macOS: Double-click the .zip file in Finder to extract it (if it wasn’t automatically extracted when you downloaded it).
• Windows: Right-click the ZIP file and choose Extract All….

Download the assignment ZIP file, unzip it, then open the project folder in IntelliJ. Do not open a file or subfolder inside the project folder.

Create one folder for all COS 126 assignments, and keep each assignment in its own subfolder.

It typically includes data files and course configuration files.

Select LIFT → New Java Class from the menu.

Use only Java features that have been covered in lecture, precept, or the assigned readings for this point in the course. If you are unsure whether something is in scope, ask on Ed before using it. For reference, the Java Programming Cheatsheet lists the Java features we use during the semester.

Yes. You may copy or adapt code from course materials, including the textbook, lecture slides, precepts, and assignment specifications. If you copy substantial code, include a brief comment citing the source. Do not copy solutions or code from outside course materials.

No. You may not use generative AI for any part of a programming assignment, including writing code, debugging, explaining errors, generating comments, summarizing, or reformatting). These assignments are designed to help you build your own ability to reason about code. Submitting AI-generated work defeats that purpose and violates the course collaboration policy.

No. We grade anonymously. Do not put any personally identifiable information in .java files or readme.txt.

• Use 4 spaces per indentation level.
• Keep lines to 87 characters or fewer in .java, readme.txt, and acknowledgments.txt file.
• Use whitespace for readability: blank lines between logical sections and spaces around operators.

• Use meaningful variable names (for example, isOrdered, not o or ordered). Loop indices like i and j are fine.
• Prefer simple conditionals: write if (isBlue) { ... }, not if (isBlue == true) {...}.
• Match the require types: if an input is specified as an integer, store it in an int.
• Match the required control flow: if the specification requires a while loop, use a while loop.
• Match the output format exactly, including punctuation, spacing, and number of lines. Remove debugging prints before submitting.
• Avoid magic numbers. Give important constants a named variable (e.g., int DAYS_PER_WEEK = 7).
• Minimize scope: declare variables in the smallest block where they are used.
• In OOP assignments, use instance variables only when they represent per-object state. Make all instance variables private.

• Add a brief comment above each logical section of code.
• Comment every method, documenting its purpose, inputs, and outputs.
• Comment any local variable whose purpose is not obvious from its name.
• In OOP assignments, comment every instance variable.
• Write comments as you code so your intent stays clear.

Yes. Our style guide is a useful additional resource. Some guidelines may not make sense yet, but they will as the semester unfolds.

Use IntelliJ (recommended). Save them as plain text files. Do not change their names or file extensions.

It is a short narrative description of your work. Use the provided template and answer every question. Do not include your name, NetID, or email address in readme.txt.

It lists who helped you (with dates) and includes the required academic integrity statement with your digital signature We grade an assignment only after acknowledgments.txt has been submitted.

Submit assignments on TigerFile. Each assignment has its own submission link.

Log in with your OIT NetID and password.

To access TigerFile, you must be officially enrolled in the course. Make sure you are using the submission link for the current semester. If you still cannot log in, post on Ed.

No. All programming assignments must be submitted via TigerFile.

• Remove debugging output.
• Upload all required files (your latest versions).
• Match the required output format exactly (spelling, spacing, punctuation, and number of lines).
• After testing locally, click Check Submitted Files and fix any reported issues.
• When you are ready for grading, upload acknowledgments.txt.

Absolutely. You may resubmit as often as you like before the deadline.

Your filename must match the required name exactly, including capitalization and the .java extension. For example, HelloWorld.java is not the same as helloworld.java. We recommend enabling “show file extensions” in your operating system settings (Mac and Windows).

Submit as usual in TigerFile. Upload acknowledgments.txt only when you are ready for your work to be graded.

They are applied automatically.

Create a TigerFile group for the assignment and add your partner. Either partner may upload files.

Create a group with one member (just you).

Yes.

It compiles your code and runs automated checks against the assignment specification. These include correctness tests and, on some assignments, performance and memory checks. It also runs static analysis (SpotBugs and Checkstyle) to flag likely bugs and style issues.

In TigerFile, open the assignment submission page. The Check Submitted Files button appears below your uploaded files.

You may run Check Submitted Files up to 20 times per assignment. For partnered assignments, this limit applies to the group.

No. The autograder checks whichever files you submit, as long as they compile.

Your code did not compile cleanly. Fix all compiler errors and resolve all warnings before your final submission. If you are stuck, ask on Ed or bring the error message to office hours or Lab TA hours.

• SpotBugs: likely bug patterns (occasionally false positives)
• Checkstyle: formatting and style rules, including course-specific checks. Treat warnings seriously and fix them when possible. If you do not understand a message, ask on Ed or bring it to office hours or Lab TA hours.

Your program does not meet the specification on the tested inputs. A FAILED result will likely reduce your score. Passing all tests is a good sign, but it does not guarantee full credit because we run additional tests when grading.

The autograder did not finish within the time limit. Common causes are an infinite loop or printing far more output than the specification requires (often due to leftover debugging output).

This typically indicates a network problem. Confirm you are online and reload the page.

No. Your program must handle all inputs in the domain specified by the assignment. For example, when grading RGBtoCMYK.java, we will always provide three integers between 0 and 255.

Yes. Some assignments provide a test client; others require you to write one. At minimum, your test client should exercise every public method at least once with meaningful inputs and print the results. For thorough testing, try additional edge cases beyond the minimum.

Follow the assignment specification. If it requires command-line arguments, read args[]. If it requires standard input, read from standard input. If it requires file input, read from a file. Using the wrong input method will not match our tests.

No. Check Submitted Files provides automated feedback. Course staff assign the final grade, and we may run additional tests when grading.

View grading feedback in codePost. We will email sign-up instructions after Assignment 0 is graded.