Announcements

Sat Oct 3

Homework policy clarifications / reminders:

• For homework problems with mulitple subproblems ((a), (b), etc.), you must include a list of sources and collaborators and (if necessary) an LLM transcript/link at the end of each lettered subproblem. Yes, even if the list is empty, and even if the list is the same for each subproblem.

  Please also remember to start your solution to each subproblem on a new page of your submitted PDF.

• You are welcome to use tools in your homework solutions that are not part of the official course materials and are not covered in prerequisite courses. (Examples include the pumping lemma for regular languages, language homomorphisms, actually-O(1)-time hashing, “segment trees” according to computational geometers, “segment trees” according to competitive programmers, suffix arrays, constant-time range-minimum queries, KMP/z-function string matching, and planar 3SAT.)

  However, your solutions must be understandable to someone who only knows the official course material and prerequisites. For each outside tool you use, your solution must include a self-contained description of that tool (including pseudocode if your tool is an algorithm), and either a proof or a reliable reference for every claim you make about that tool (including correctness and running time). LLMs, Geeks4Geeks, and Wikipedia are not reliable references.

Tue Sep 30

• Solutions for Midterm 1 are available.
• Solutions for Conflict Midterm 1 are available.

Sun Sep 28

• Another slightly different set of Midterm 1 Practice 2 solutions is available, along with a wwalkthrough video, this time with sound! (Sorry about the audio screwup on the first video.)
• Solutions and a walkthrough video for Midterm 1 Practice 3 are available.

Fri Sep 26

Midterm 1 Practice 2 solutions are available.

Thu Sep 25

Midterm 1 Practice 1 solutions are available. Anything edited or added after today's lecture period is written in a darker color. There is an alternative solution to Problem 1(b) given in the scratch notes, but please remember that we will only grade the first solution you submit for each problem.

Web Sep 24

Homework 4 solutions are available.

Tue Sep 23

• Practice exams for Midterm 1 are available. We strongly recommend attempting each of these practice exams under exam conditions — two hours alone in a quiet space with a one-page sheet sheet, but no other notes or internet — before looking at any solutions. Handwritten solutions and walkthrough videos for each practice exam will be posted on the days listed below.
  • Practice 1 (answer booklet) — solutions released late Tuesday
  • Practice 2 (answer booklet) — solutions released late Friday
  • Practice 3 (answer booklet) — solutions released late Sunday
  The format of the actual exam will match these practice exams. At the actual exam, we will pass out the question sheet, give everyone a few minutes to read the questions, pass out the answer booklets, and then start the clock.
• Midterm 1 will be held in the following locations. Please go the room that matches the start of your last name.
  • A–J: 141 Wohlers Hall — (≤150 students in 306 seats)
  • K–M: 101 Armory — (≤96 students in 200 seats)
  • N–Sc: 120 Architecture Building — (≤62 students in 130 seats)
  • Sh–Z: 103 Mumford Hall — (≤100 students in 215 seats)
  You may find these floor maps for all buildings on campus helpful.

Thu Sep 18

Midterm 1 will be held on Monday, September 29, from 7pm to 9pm.

• The exam will cover all material covered in Homeworks 1, 2, 3, and 4: induction on strings and languages, regular languages, regular expressions, DFAs, NFAs, fooling sets, regular language transformations, and context-free languages and grammars
• The exam will be split across multiple rooms by last name. We will announce locations for the exam early next week.
• Please read and understand the exam policies. In particular, you are allowed to bring one double-sided 8½"×11" handwritten cheat sheet to the exam.
• We are offered multiple optional review sessions next week:
  • Thursday, September 25, in place of the usual lecture
  • Thursday, September 25, in place of the usual homework party
  • Friday, September 26, in place of the usual labs
  • Sunday, September 28,, in place of the usual homework party
  ACM is also planning to offere an independent review session; stay tuned for more details. There will no homework party on Monday, September 29.
• We will post multiple practice exams early next week, which will have the same format (but different questions!) as the actual midterm . We will cover these practice exams in the review sessions. Solutions and walkthrough videos will be released for each practice exam after the corresponding review session.
• We are offering a conflict exam on Tuesday, September 30. If you cannot attend the regular midterm for any of the reasons outlined in the student code, please fill out this registration form no later than Friday, September 26. On Monday, September 29, we will email the precise time and location of the conflict exam to students who have filled out the registration form.
• If you have a DRES accommodation, you are welcome to take the exam at the DRES Testing Accommodation Center either Monday or Tuesday. We strongly recommend scheduling your exam at TAC immediately if you have not done so already.

Thu Sep 18

Homework 3 solutions are available.

Thu Sep 11

Homework 2 solutions are avialable.

Wed Sep 10

Homework 1 has been graded.

A significant number of HW1 submissions did not include the required list of sources and collaborators, or properly cited an LLM as a source but did not include the required transcript (or link). We applied a significant score penalty to those submissions after normal grading. You can have that penalty removed by submitting a regrade request. You do not need to supply the missing information with your request. Regrade requests for Homework 1 can be submitted any time before September 24 at 11:59pm.

The same penalty-refund policy will apply to Homeworks 2 and 3, but not for later homeworks.

Tue Sep 9

• The deadline for Homework 2 has been extended to Wed Sep 10 at 9pm due to a discrepancy on the Course Calendar page.
• Some clarifications of homework policies:
  • The list of collaborators and other sources should be given as a separate page included after each lettered part of a homework problem (or after the whole problem if it consists of a single part). Please do so even if you have nothing to cite ("Sources and collaborators: $\varnothing$") and even if your list is the same for each part. Doing so will greatly aid any graders focusing on individual parts. We understand this policy is somewhat different than what was asked for earlier, so we'll only start enforcing it for Homework 3.
  • If you use an LLM for any part of a problem, you must provide a complete transcript of the "conversation" starting on the same page as or the next page after the list of sources and collaborators. A URL for the transcript is sufficient if you can guarantee it will remain active through at least January 2026. (A clickable link is greatly preferred.) If you don't use a URL, please use as many pages as necessary to keep the transcript readable.
  • On that last note, the two page limit for each problem mentioned on the website is merely a (very firm) suggestion to warn you when you've gone off the rails. It is not enforced (beyond the grader giving up when there's too much to read), and it certainly does not apply to any citation list or LLM transcript.

Thu Sep 4

Homework 1 solutions are available.

Tue Sep 2

• Starting this Thursday (September 4), we will hold weekly homework parties every Thursday 6–8, Sunday 4–6, and Monday 6–8 in Siebel 0216. These are structured office hours where groups of students can work together on homework, with the guidance of course staff.
• Reminders about the homework due tomorrow:
  • Please read the homework policies. In particular:
    • Every homework submission must include a complete list of all sources and collaborators. (You do not need to cite official course materials or sources for prerequisite material.) If your set of sources and collaborators is empty, write “Sources and collaborators: $\varnothing$”.
    • If you use an LLM for any reason, you must include the LLM in your list of sources, and you must submit a complete transcript of your prompts and responses.
  • Please read the standard grading rubrics, especially the stadnard induction rubric. This is how we will score your homework.
  • Please read the lab solutions and the solved problems in the homework. These model the structure and level of detail that we expect in your homework solutinos.
  • Exactly one member of each homework group should upload your submission and identify the other group members to Gradescope. You can submit as many revisions as you like before the deadline, but you must identify your group members every time you submit.

Sat Aug 30

• This coming Monday September 1st is Labor Day, which is a university holiday. All office hours for that day are officially canceled.
• Starting next week, Emily will hold her regularly scheduled office hours Wed 11-12 and Thur 4-5. Office hours for the rest of the course staff along with other events can be found on the calendar embedd in the Weekly Schedule page.

Fri Aug 29

Today's lab handout has been revised to remove an error and clarify one of the problem statements; all revisions are highlighted. Solutions for both of this week's labs are available.

Wed Aug 27

• The course Discord server is now publicly available to those who want to read posts. Any current student of UIUC (and not just those registered for this class) can post as well after providing their netid and password through a link in the server's #rules channel.

Tue Aug 26

• Jeff didn't have much time to do the technical portion of today's lecture, so Emily recorded another take that goes a bit slower and discusses more examples of proof by induction.
• Emily's first office hours will be tomorrow (Wed Aug 27) from 11 to 12.
• All office hours will be announced on Ed Discussion and Discord and posted on the Google calendar on the weekly schedule page. In particular, Jeff's first office hours will be tomorrow (Wed Aug 27) from 3 to 4.
• If you are waiting to register for the class for any reason, please submit Guided Problem Set 1 and Homework 1 as if you are already registered. Because we need to release solutions immediately after the submission deadline, we cannot give homework extensions to students who register late.

Mon Aug 25

Guided Problem Set 1 and Homework 1 are available. Normally guided problem sets are due Monday at 9pm, and homeworks are due Tuesday at 9pm; both deadlines are delayed 24 hours this week because of Labor Day.

Wed Aug 20

• Welcome! We’re working hard to get everything set up here before the semester begins. Meanwhile, you may notice several inconsistencies, broken links, and inaccurate dates.
• As in past semesters, there are two independent sections of CS/ECE 374. This is the web site for Section A, or more formally: lecture section AL1 and lab sections AD*. Section B, taught by Nickvash Kani and Daniel Alabi, has a separate site.