Lightly modified from documents by Nick Troccoli, Jerry Cain and Lisa Yan, based on documents by Julie Zelenski and others

We highly recommend revisiting the assignments and labs and reviewing them in detail. Each of them contains post-task self-check questions at the end that you can use to review the material. The labs also have some extra problems you can use for practice. The K&R and B&O textbooks also contain many exercises if you want additional problems to work.

Date/Time/Location:

Monday, December 9th, 3:30-6:30PM PDT in CEMEX Auditorium
Monday, December 9th, 8:30-11:30AM (if and only if you have another final at 3:30PM) in Lathrop 282

Overview

The final exam will be held during our registrar-scheduled exam time listed above, with the listed alternate for those who have a competing final exam or final presentation during the officially scheduled time. Unless you've registered with the OAE, you're expected to take the exam at the 3:30PM time (or the 8:30AM time if you hold a conflict with the 3:30PM time).

Logistics

The exam is a closed-book, closed-note, closed-computer pencil-and-paper exam. The exam will include a reference sheet of essential details such as prototypes for standard library functions (e.g., strcpy, strlen, malloc), commonly used constants, as well as an additional reference sheet with the common x86-64 assembly instructions - you can find links to both further down on this page.

Course staff will be present and available to answer any clarification questions you have while taking the final. Understand we can't answer questions beyond those asked to clatify what's being asked.

We understand a written exam is not the same as working with a compiler as you do on the myth machines, and we account for that in how we design and grade the exam. We are assessing your ability to think logically and use appropriate problem-solving techniques. We expect you to express yourself in reasonably correct C, but we will be lenient with errors that are syntactic rather than conceptual.

During the exam, you may consult:

• the provided reference sheets that includeprototypes for standard library functions (e.g., strcpy, strlen, malloc) and common x86-64 assembly instructions (we will provide at the exam)
• the provided blank scratch paper (we will provide this at the exam)

You are not permitted to use any other materials, such as printouts (notes, slides, code, practice exams, etc.), other textbooks, or electronic devices (computers, iPads, Kindles, calculators, music players, etc.).

The exam may be a mix of short answer, multiple choice, code reading, code writing, etc. questions. Understand that we're under not obligation to mimic the structure of past exams. We promise to ask questions that fairly exercise your understanding of the material covered in the course.

There are practice exams from prior quarters below.

Material Covered

The final is intended to assess your understanding of the content covered throughout the course. The priority is on material that figured prominently in the assignments, labs, lecture, and reading (this list is in order of decreasing emphasis). The topic coverage for the final exam will be comprehensive and span the entire quarter, but expect more material covered after the midterm (i.e. >= lab4 and assign4, since assign4 was only lightly covered on the midterm) to be emphsized more.

Topics Summary

Check your rear-view mirror for the very impressive list of things you've learned in 107!

• All about C and memory: C—strings, arrays, pointers, void*, pointer arithmetic, typecasts, function pointers, generics, stack and heap
• Data representation: bits, bytes, ASCII, two's complement integers, pointers, aggregate types (arrays and structs)
• x86-64 assembly: data access and addressing modes, arithmetic and logical ops, implementation of C control structures, call/return
• Address space: layout and purpose of text/data/stack/heap segments, handling of different variable scopes/types
• Runtime stack: caller/callee protocol, parameter passing, use of registers
• Memory and heap: stack versus heap allocation, heap allocator implementations, strategies and tradeoffs
• Performance and optimization: compiler optimizations, profiling

Honor Code

The exam is to be completed individually and without any assistance from a partner or other students. Follow the Stanford Honor Code (see link on main course homepage) during the exam: submit only your own work, do not use unpermitted aids on the exam, and say something to the instructors or students in question to prevent any inappropriate activity conducted by others surrounding the exam.

Grading

(Same as midterm exam)

For coding questions, the majority of the points are typically focused on the correctness of the code. However, there may be deductions for code that is roundabout, awkward or inefficient when more appropriate alternatives exist. We will reward the simple, direct approach for its good design decisions and such code will likely have fewer correctness issues, so the choice of appropriate design can have a large impact. For example, we expect you to leverage appropriate features from the standard libraries; re-implementing that functionality wastes your valuable time and introduces opportunity for error.

Note that certain problems may have certain constraints (such as only using certain material, etc.) that you must follow to earn full credit. These constraints are not intended to make things difficult; typically, we are trying to guide you in the direction of a more straightforward solution. If you disregard these instructions, you are likely to lose points, either for not meeting the problem specification and/or for errors introduced when attempting a convoluted alternative. We reserve the right to deduct points for extremely inelegant or inefficient code that dodges the spirit of the problem.

• You are not required to write #include statements. Please do not abbreviate any code (such as writing "x2" next to code to copy it twice). Abbreviated code will not be graded.
• For questions expecting code, pseudo-code (writing English sentences and phrases instead of code) will typically earn little to no points. For example, writing "In this part of the code, I want to open the file and read each line and print it" will not earn any points.
• You should include only your answer in the target area, scratchwork should be included in the surrounding area. An answer to a problem not in the designated answer pages for that problem will not receive any credit.
• Unless otherwise specified, it is fine to write helper functions to implement the required behavior.
• Style and decomposition are secondary to correctness. Unlike the assignments where we hold you to high standards in all areas, for an exam the correctness of the answers dominates the grading. Decomposition and style are thus somewhat de-emphasized. However, good design may make it easier for you to get the functionality correct and may require less code, which takes less time and provides fewer opportunities for error. Comments are never required unless specifically indicated by a problem. When a solution is incorrect, commenting may help us determine what you were trying to do when we attempt to give partial credit.
• We are lenient on syntax. We won’t trouble you about most small syntax errors (forgetting semicolons or spaces, for example) as long as your intentions are clear. Having said that, beware that if your syntax errors cause ambiguity (e.g. very unclear curly braces), we might not get the correct meaning. Additionally, there are subtleties that matter immensely, e.g., a int** is just one character different than int*, yet there is a world of difference between the two!
• The majority of the points for a problem will be reserved for grading the critical core of the code. For example, if we ask you to write a function that processes a generic array, only a tiny fraction of the points will be allocated to tasks such as initializing the counter or iterating over the right bounds, while the bulk of the points will be gained or lost in the tricky details of whether you correctly handle the void*s. Being off-by-one in the loop is a tiny deduction, but being a level of indirection off or applying the wrong cast is a much, much larger issue. Be sure to focus your attention accordingly!

Exam Reference Sheets: Note: the reference sheets will be included with the exam.

C Reference Sheet Webpage | C Reference Sheet PDF
(This is the same reference sheet as on the midterm exam)

Assembly Reference Sheet
(This is the same assembly reference sheet we have used in class and labs)

Practice Materials:

Guide for how to approach and succeed on CS107 exams.

Note: some of the exams include questions covering floats, which is not included this quarter on our final exam topics.

Practice Exam 1: PDF | Solutions
This is based on the final exam from CS107 Winter 2018.

Practice Exam 2: PDF | Solutions
This is based on the final exam from CS107 Fall 2017.

Practice Exam 3: PDF | Solutions
This is based on the final exam from CS107 Fall 2018.

Practice Exam 4: PDF | Solutions
This was the final exam from CS107 Fall 2022.

Practice Exam 5: PDF | Solutions
This was the final exam from CS107 Fall 2023.

Extra Practice Problems: PDF | Solutions