Monday, December 20, 2010

Looking at exams --after 3 Jan

Correction: Please come after 3 Jan if you want to see your exam. Sorry about this -- at the moment the exams are not in a sorted order, so we cannot easily find exams to show you. --Bill

Wednesday, December 15, 2010

Final Course Grades

Are in the system! Have a good break -- Bill and Chris

Tuesday, December 14, 2010

Final exam grades released

We have released the grades for the final exam. If you would like to see the exam, you may come to Dr. Scherlis' office *next week*. The mean and median scores were 119 and 120 points (out of 164), respectively. Have a nice break!!!

Sunday, December 12, 2010

Office Hours

I'll hold office hours tomorrow at my usual time and place for any last minute questions.

Saturday, December 11, 2010

Extra Office Hours

I'll be having extra office hours on Monday from 1:30 PM - 3:00 PM for last minute content-based questions/review. Please do not come expecting to find out the specific material on the exam.

Partial Solutions Posted

There are now partial solutions to the exam we went over in the review posted on the lectures page.

Final Exam Note Sheet

To clarify, you are allowed one piece of paper worth of notes for the final on Monday. The same policy applies here as it did for the two midterm exams: your piece of paper must be 8.5"x11", you may write on both sides of it, and it shouldn't be typeset.

Wednesday, December 08, 2010

Sample final exam

A sample final exam has been placed on the portal on the lectures slides page. Please look over the exam prior to the review session, which is at 2pm in Wean Hall 7500 on Saturday the 11th.

Saturday, December 04, 2010

Portal updated

PDFs and video links are now posted for all sessions. Good luck on the final! --Bill

Friday, December 03, 2010

Final Review

The review for the final exam will be in Wean 7500 starting at 2:00pm on 11 December.

Wednesday, December 01, 2010

An ADDITIONAL submission to make on Front Desk

A new submission portion to the chess submission named "Chess: Improved versions" has been created on Front Desk. You will need to submit the code with any improvements you made to the unit tested version for this portion of the chess assignment.

You still need to submit the unit tested version to the original "Chess" submission portion.

Note that the due date for this new portion is Dec 3rd at 11:59PM, when the pool closes.

Office Hours and Final Review

Office hours for this semester will end this week with the end of classes. That specifically means that there will be no scheduled office hours in the week before the final. We'll still be reading the bboards, so you should post questions that come up as you study there. If you're really stuck, feel free to contact your specific TA and try to arrange for help in person if you need it.

There will be a mass review for the final exam in the afternoon of 11 December. The details of when and where will be announced as we release a practice exam for you to work on in preparation for that review.

Do not rely on this practice exam and review as your only way of studying for the exam! The final will cover material from the whole semester, and it therefore warrants serious preparation beyond what we go through with you.

Correction: Chess Due Dates

Due to some mis-communications, we have decided to extend the due date for the chess. The unit tested portion of this assignment, namely the evaluator and Alpha Beta Searcher, is due Thursday, December 2nd at 11:59:59pm. The competition pool will still end the last day of the semester: Friday, December 3rd, at 11:59:59pm. Your scores against Jackbach and Bachchoy will be taken on: Friday, December 3rd, at 11:59:59pm.

Sunday, November 28, 2010

More office hours news!

I am running late so I'm going to push my office hours to Monday. Since Aaron isn't having office hours, I'll take his time slot (4:00 - 5:30) but in my location: WeH 5205.

Aaron's Office Hours on Nov. 29th

I will not be able to have office hours this week on Monday, Nov. 29th. As always, if you have questions or concerns, please send me an email or post to the discussion board.

Tuesday, November 23, 2010

Office Hours Today

Because of the break, I will not be having office hours today. Have a nice break! -ankur

Thursday, November 18, 2010

Graphs Grading and Chess Late Days

Many of you had trouble with tests timing out on FrontDesk in the run up to the graphs deadline. This was because the time allowed for each test was conservative, and a large number of tests were being run at the same time. Therefore, in the interest of fairness, we will be manually resubmitting everyone's graphs submissions as we grade them. This means that the tests will be rerun when the system isn't overloaded. Your grade will either not change or go up if your code was unfairly timed out. Since the staff will be doing the submissions, your late day usage will not be affected.

There have also been some questions about how late days will be used on Chess lab. Unlike Graphs, the previous partner assignment, we are allowing you to use up to two of the maximum of your partnership's late days, which is to say

min(2, max(a's late days, b's late days))

For example, if I have no late days, and my partner has five then we can submit our Chess code one or two days late. If, on the other hand, I have 1 late day and my partner has 1 late day, we can only submit one day late.

The deadline for chess is 23:59 on 30 November. That means that if you have two late days to use, you can submit up to 23:59 on 2 December. The competitive pool will remain open until 23:59 on 3 December, which is the last day of the semester. At that time, we will snapshot the leader board and assign extra credit points as described in the handout.

Please note that the code you submit to FrontDesk is the only code that we'll use to assign testing and style points. If you choose to continue hacking on your chess AI beyond the formal deadline, that's up to you, but it will only count towards your standings in the competition.

Saturday, November 13, 2010

Chess signups

The list of andrewids we were using was out-of-date. We've updated it now. So, everyone should be able to sign up at now.


Chess lab has been released. You may now sign up with your andrew id at You can Please read the documentation on Frontdesk in its entirety before starting the assignment! There is no theory component. The unit tested component is due on Nov 30. You may use late days for the unit tested part of the lab. The pool will close on Dec 2. You may not use late days for the pool. Have fun!

Wednesday, November 10, 2010

Extra-Special Office Hours

I will be holding extra office hours from 1:30 - 3:00pm tomorrow to help answer any lingering questions on Graphs lab. I'll be at the 6th floor couches of Wean.

MST-TSP Approximation Clarification

We've been getting lots of questions about this part of the lab; this is mostly our fault, as the documentation is unclear and possibly misleading.
Some clarifications:
1) When you are completing the graph, connect every two vertices with an edge whose weight is the shortest path between them (even if the vertices are adjacent, this may not be the shortest path)
2) Once you've gotten the order to visit the tour in, you should walk along the "edges" (i.e. shortest paths) in the MST to get from one vertex to another
3) Your tour should end with the start vertex, and shouldn't start with it.
Note that clarifications 1 and 2 aren't the only way to produce a "valid" tour (one that meets the spec), but hopefully explaining it this way makes it easier to understand and implement.
We are very sorry that this part of the assignment wasn't explained as well as it should have been.

Tuesday, November 02, 2010

Midterm grades released

The grades for the 2nd midterm have been released. The min,max,mean, median were 19.5, 69.5, 53, and 54 points, respectively, out of a total of 72 possible points. Your TA will return your exam tomorrow during recitation.

Monday, November 01, 2010

Graph Theory Corrections

Based on a few questions that keep coming up, here are a list of clarifications for the theory assignment:
Question 1: The theorem is intentionally wrong. We aren't asking for a counterexample, we are asking you to find the flaw in the proof.
Question 3b: Just like in part a, you are allowed to manipulate the graph.
I'll update this list if more things come up.

Sunday, October 31, 2010

scheduling issues

Due to unforseen events unrelated to this class, I was unable to attend the review session; further, I won't have office hours today. Sorry for the sudden change. so, I will have office hours tomorrow, Nov 1, 5:30-6:30pm. So sorry for the confusion. This was unavoidable today.

Friday, October 29, 2010

2nd Midterm Review Posted

I just posted the second midterm review on the lectures portion of the portal. Good luck! As a reminder, the review is this Sunday, from 2-4 PM in WEH 7500.

make-up office hours

Since I missed yesterday's office hour, I will hold one this afternoon from 2-3pm.

Thursday, October 28, 2010

Late for office hour

I will likely be late for my office hour by about 1/2 an hour, possibly more. Sorry for the inconvenience.

Wednesday, October 27, 2010

Graphs Lab Released

Graphs lab has been released on FrontDesk. For this assignment, you will be allowed to work in pairs for the programming portion, however, the theory is still an individual assignment. The theory is due on November 3rd, in recitation. The programming portion of the assignment is due on November 11th. This lab is very long so we strongly advice that you start early!

Monday, October 25, 2010

Update to seamcarving assignment

I just updated the seamcarving assignment on FD to address an ambiguity that was pointed out with multiple valid lists. An example of such a list is {1,9,9,1} for which both {1,9} and {9,1} are valid minimum weight subsequences. Note, however, that an example like {1,3,2} only has one valid min-weight subsequence, {1,2}, since it was specified that your list-finding algorithm should find the longest (greediest) valid subsequence. With respect to logistics, any new submissions made to FD support this change. If you've finished the assignment, I'd highly recommend resubmitting to make sure that your code still works (it should). Furthermore, if you download a new copy of the stub code, the runTestTuples() method you get has been adjusted to reflect this change. Good luck!

Tuesday, October 19, 2010

seamcarving clarification (theory)

For 2(f)(i), you can just let T(n) be the runtime of Stack(n) (not the solution to finding the tallest stack). If you do it the other way, you'll still receive credit. For 2(f)(ii), 2(f)(iii), you should actually try and find the tallest stack, not just compute Stack(n). Sorry for the confusion.

Monday, October 18, 2010

Makeup Office Hours for jpaulson

I missed my office hours this evening; I sincerely apologize to anyone who went looking for help and couldn't find me.
To atone, I will be holding makeup office hours tomorrow evening from 6:30-8:00pm in the Wean 8 couches.

Seamcarving Clarification (Code)

Your list-finding algorithm should be greedy; that is, include as many elements as possible. This is a generalization about the comment made with respect to 0's in the documentation (that they should be included). If the list is [3,5,2], you should return [3,2]. Similarly, if the list were [0,3,5,2,0], you should return [0,3,2,0].

Sunday, October 17, 2010

Office Hours

Due to me not being in the appropriate state, I won't have office hours today.

Friday, October 15, 2010

Typo in seamcarving theory

There was a typo in the seamcarving theory assignment. In 2(e) it should be "max" instead of "min". It has been updated on the lectures portion of the site.

seamcarving released

The seamcarving lab has been released on FD. Please be sure to complete the theory first, because its solutions will be invaluable for the programming component. The theory has also been (very slightly) updated, to reflect a new number of total points on the lab (138). All of the questions and content is still the same.

Wednesday, October 13, 2010

Anonymous Posting on the Discussion Board

From now on, the staff will stop responding to posts on the discussion board that are anonymous. If we see such a post, we'll post a reminder of this policy and then delete the post. Please repost your question correctly identifying yourself.

seamcarving theory released

HW4 (seamcarving) theory has been released on the "lectures" section of the portal.

Tuesday, October 12, 2010

Revised slides

There is a more elegant solution to handling the problem of testing bipartiteness in directed graphs than the one I presented in class. So, I have updated the slides on the portal, and I will go over the new solution in class on Thursday.

Thursday, October 07, 2010

Compression Code Addendum

I'm encouraged to see that many of you have been making submissions to FrontDesk for the compression assignment. Keep up the good work! Below are a few comments I wanted to share with the entire class concerning this assignment:

1) You are not implementing MyPriorityQueue for kicks and giggles. You are expected to call your own code (and not Java's PriorityQueue) when you implement Huffman encoding.

2) A significant portion of the grade for this assignment is in hidden tests. The staff tests visible on FrontDesk only test very simple cases. Passing the visible staff tests does not ensure you will do well on this assignment. You need to write extensive unit tests to ensure your compression algorithms are working properly.

3) The new FrontDesk has been performing quite well and we haven't had any serious issues with it being overloaded since the switch. However, Compression is significantly more computationally intensive than Snakes, so do continue to submit well before the deadline. In addition, if you submit a unit test that takes too long to complete, your process will time-out and all the remaining unit tests will fail to run. We strongly recommend including a timeout of 1 second for all of your unit tests. For example, the following code contains an infinite loop, but will stop execution after one second:

    @Test(timeout=1000) public void infinity() {

The advantage is that if a unit test times out, the remaining unit tests will still be run. You will likely want to run some of your more intensive stress tests locally without a timeout. If these tests cannot complete within the one second timeout on FrontDesk, that is ok as long as you stipulate this in a comment.

4) To complete the assignment you may find it necessary to perform some fairly low-level byte manipulation. This is a useful skill to learn, but it is not fundamentally what we are testing in this assignment. If you get stuck with bit mangling or byte conversions, please ask for help.

As always, if you run into problems or ambiguities, please share them with us on the discussion board!

Wednesday, October 06, 2010

2nd midterm

We decided to move the 2nd midterm to November 2nd. The schedule has been updated.

Tuesday, October 05, 2010

Quiz in Recitation Tomorrow

Just a quick heads up that there will be a quiz in recitation tomorrow. Don't miss it!

Wednesday, September 29, 2010

Homework 3: Compression

Homework 3, a.k.a. Compression, is now available. The theory portion will be due at the start of recitation on 6 October 2010 and the programming portion will be due roughly a week later at 12:59pm on 12 October 2010. Remember, the programming assignments continue to increase in difficulty, so start early. Enjoy!

Monday, September 27, 2010

Picking up exams

We've decided that the most efficient means of handing back exams is via office hours and recitations. So, please wait until your TA's next office hour or recitation (whichever comes first) to pick up your exam. Sorry for the confusion.

Thursday, September 23, 2010

Midterm 1 grades released

The grades for the midterm have been released. The mean and median scores were 44 and 45 points (out of 73 points total), respectively. You may pick up your exams at your TA's office hours or the next recitation (whichever comes first).

Wednesday, September 22, 2010

Theory Homework Policy Clarification

From today onward, students who do not turn in the theory assignment by the beginning of their assigned recitation will get a 50% penalty if they hand it in by 3:30pm the day it is due. Beyond 3:30, the theory assignment will be graded as a zero.

FD is Back!

FrontDesk is back. You can access it by clicking "Assignments" from the portal page.


Any student with special accommodations for the exam should send me and prof. Scherlis an email confirming the arrangements as soon as possible.

Tuesday, September 21, 2010

LaTeX Published

A source file from our quick LaTeX intro has been published on the lectures schedule page. The PDF that it creates is also there for reference. Some of our favorite online LaTeX references are listed below.
Here are some links to various LaTeX editing programs. One of the easiest ways to edit LaTeX, though, is to create and edit the .tex source file with emacs, vim, or your favorite text editor, and compile it with pdflatex on the command line.
Happy typesetting!

    Saturday, September 18, 2010

    FD Downtime

    FrontDesk will be down until at least tomorrow evening while we do technical updates. You do not need it for the midterm review or snakes theory.

    Friday, September 17, 2010

    Midterm Review Posted

    The midterm review material has been posted to the lectures portion of the site. We will go over the review on Sunday during the Midterm Review Session (2-4 PM, WEH 7500). Please note that solutions may not be released, so you should attend the review if you are interested in confirming your answers. Good luck studying!

    Snakes Updated

    Hi All,

    There was a slight error in the snakes theory.pdf file. The list of hash codes in figure four was incomplete. It showed up as
    <9, 10, 10>
    which was text that was left over from drafting the assignment. The real list of hash codes you should use is

    <17, 12, 128, 10, 7, 14, 129, 132, 127, 96, 42>

    The theory.pdf and files linked on the lecture page and from FrontDesk now reflect this.

    Sorry for the confusion!

    -- Ian

    Thursday, September 16, 2010

    Snakes Released!

    Homework 2, Snakes, has been released! It is available on FrontDesk immediately.

    The theory portion of Snakes will be due at the start of next week's recitation, which is 22 September 2010. The theory portion has been scaled back slightly due to the late release of the assignment. The programming portion will be due roughly a week later at 23:59 on 28 September 2010.

    To address the latency and responsiveness issues that we had with Expression Trees, FrontDesk will be down for a period of time this weekend as it migrates to new hardware. You may submit partial solutions to snake to FrontDesk before then if you wish, but you should not count on them still being there when FrontDesk returns next week. There will be more detailed announcements about this outage as it becomes relevant.

    slides and videos posted

    Slides and videos are now posted --Bill

    Wednesday, September 15, 2010

    Midterm Review Session Sunday 2-4

    We will have a midterm review session on Sunday (9/19/10) from 2:00 PM - 4:00 PM in WEH 7500. The midterm review sheet will be posted shortly.

    HW2 (snakes) Delayed

    The release of HW2 will be delayed slightly. It should have come out last night as HW1 was being collected, but didn't. It will be out later this evening.

    Tuesday, September 14, 2010

    Ankur's Office Hours Shifted

    Ankur's office hours will start at 4:30 and run till 6:00 today.

    Monday, September 13, 2010

    Aaron will not have office hours today

    I became violently ill over the weekend and have not fully recovered. As a result, I am canceling my office hours today. I apologize for any inconvenience this may cause and I would encourage you to visit Andrew or Jon who also have office hours today.

    Thursday, September 09, 2010

    no office hour today

    I am traveling to a conference today so I must cancel my office hour.

    Tuesday, September 07, 2010

    LaTeX Tutorial (update)

    The LaTeX tutorial will be held tonight from 5:30-6:30 in Doherty Hall room 1112.

    Monday, September 06, 2010

    Videos now online

    The lecture videos are now available via the Lectures link on the portal page. Everyone currently registered and able to authenticate via should be able to click through. The value of the videos: (1) Search, based on slide content, so you can rapidly find that explanation of the Master Theorem or other bit of content, and (2) Note-taking, both private and public (be civil), that also supports search. The videos are not intended (or particularly useful) as a substitute for appearing at the lecture. Please send us comments and suggestions.

    Sunday, September 05, 2010

    Update to HW1 Theory

    The theory assignment was just updated to fix some inconsistencies in question 3. The source and PDF have been updated in the "lectures" section of the portal.

    LaTeX Tutorial

    Due to popular demand, the TAs will be running a short tutorial on using LaTeX. It will be on Tuesday evening from 5:30pm to 6:30pm. We're still working on getting a room, so we'll make an announcement about that when we know.

    Saturday, September 04, 2010


    Please attend the recitation that you are signed up for in FrontDesk. Do *not* go to another recitation. Your TA's have been instructed to not grade quizzes and theory questions handed in at the wrong section. We are sorry to have to be so strict, but we are already over the official enrollment limit. It is not fair to students who are officially enrolled to have to sit on the floor, nor is it fair to your TAs.

    Wednesday, September 01, 2010

    exprtree released

    HW1 (expression trees) has been released on Front Desk! Note that the theory is available through the lectures portion of the site. The theory is due next Wednesday (Sep. 8) at the beginning of recitation, and the programming component is due the following Tuesday (Sep. 14). Please post any questions on the discussion board and feel free to come to office hours to get help. Good luck!

    Lecture Portion of Website Fixed

    Sorry for the long delay on the lectures portion of the website. There was an internal technical error. It has now been resolved, and the slides from past lectures are now up. Enjoy!

    Tuesday, August 31, 2010

    HW0 theory questions

    Please hand them in during recitation tomorrow (Sept 1).

    Problems with FrontDesk?

    FrontDesk is working and not being able to access FrontDesk is not a valid reason to submit your homework late. If you are on a wait list or recently enrolled in the course, your Andrew ID may not be registered with the system. Students in this situation need to contact a TA immediately (after 5pm we may not respond until the next day) so we can give you access to FrontDesk.

    Sunday, August 29, 2010

    LaTeX and hw0

    The write up for hw0 on Frontdesk has the following statement in the "Theory Questions" section:
    You must type your answers (no handwriting). We recommend using LaTeX and provide the .tex source for each assignment to use as a template, although this is not required.
    The first part is correct---you are not to hand in handwritten answers to the theory questions on this or any subsequent homework. The second part is going to be correct for future assignments, but it is an error for this one.

    There is no sample .tex file in the hw0 distribution. Since the questions for this theory section are more to make sure you're able to find all the course resources and less about fun greek letters, we're not going to worry about it this time.

    Since we're only emphatically recommending that you use LaTeX and not actually requiring it, you won't be submitting .tex files this term. The theory questions will typically be collected in recitation, so we'll actually be taking a paper print out. Our only hard requirement is that it not be hand written.

    That said, LaTeX is a fantastic tool and well worth learning as early as possible. If you have trouble using it this term, you should feel free to post to the dboard looking for help. If you've never used it before and would like to try, the following are very good resources to learn about it:

    In future assignments, we will include a starter LaTeX file and some simple instructions so that you can get good looking results quickly.

    Thursday, August 26, 2010

    Waitlist issues

    If you are on a waitlist, please read this: We are at capacity for sections C, D, and E. If you are waiting for one of these and can instead go to A, B, F, or G, please do so ASAP so we can admit you to the course. We are also assessing if we can let more in to C, D, E -- but this will take a bit longer! -- Bill

    hw0 released

    HW0 is now released. You can access it through the "Assignments" link on the portal. There is both a programming and theory component, and you will find the theory linked through the schedule on the "Lectures" page. Traditionally, we released the theory in the source code of the assignment and expected you to submit it via frontdesk. However, this semester we are requiring theory assignments to be typed and submitted in class. For HW0, you must type your solution and submit it in lecture on Tuesday (Aug 31st).

    Monday, August 23, 2010

    Welcome to 15-211, Fall 2010!

    This portal will be the primary means for communicating with the class. Here you will find a calendar (including staff office hours) and a discussion board to ask/answer questions you have about the course, lectures, assignments and exams.

    Tuesday, May 04, 2010

    Final exam today at 1 pm

    Just a reminder: the final exam is today at 1 p.m. in UC McConomy.

    Saturday, May 01, 2010

    Turn in chess_final_handin

    If you haven't submitted the final code that you used on the chess server, please submit that to chess_final_handin as soon as possible. (Your performance against the bots and in the 211 pool has already been recorded.) Only one person in your group needs to submit this.

    Wednesday, April 28, 2010

    Final Exam Review Posted

    The final exam review has been posted to the lectures portion of the site. As a reminder, the review will be on Sunday (May 2) from 2-4 PM in Wean 7500.

    Tuesday, April 27, 2010

    course and TA evaluations

    Please evaluate the course and your TA:

    note sheet for final exam

    As with the midterm, you may use a 1-page (front and back) handwritten note sheet during the final exam. Your sheet may not be typed or photocopied and must be handwritten by you.

    Sunday, April 11, 2010

    Homework 6 (Chess) has been released

    Homework 6 (both theory and programming) has been released. The programming portion has a fairly large amount of documentation, please read it carefully. You may work in partnerships of 2 for this assignment.

    Monday, April 05, 2010

    Graphs starter test updated

    A change has been made to You can either download the stubs again and grab that file, or you can look on the Googlegroup (link) for a more detailed description of the changes if you'd rather patch them in manually.

    Tuesday, March 23, 2010

    Homework 5 has been released

    Homework 5 (both theory and programming) has been released. The programming portion is fairly involved and has a major design component, so please start early.

    Wednesday, March 17, 2010

    Recitation 09 (3/17/09) Solutions Posted

    The recitation worksheet and its solutions from today (3/17/09) have been posted to the lectures section of the site.

    Tuesday, March 16, 2010

    Office Hour Rescheduling

    Mark's office hours are being rescheduled for this week and are now at Friday at 3-4:30pm. To make sure there's enough office hours before the theory is due, Ankur's hours are also rescheduled from and are now at Wed 4:30-6pm.

    Tuesday, March 02, 2010

    midterm grades on Frontdesk

    Your midterm exam grades are available on Frontdesk. The exam mean was 53, with a median of 51 and standard deviation of 16.

    Charlie's office hours rescheduled this week

    My office hours tonight conflict with our exam-grading session. I'm moving my office hours this week to Wednesday, 2:30 - 4:30 p.m. in GHC 9008.

    Monday, March 01, 2010

    Midterm Review Solutions

    Midterm Review Solutions have been posted in the lectures portion of the site.

    Sunday, February 28, 2010

    HW4 theory released

    The theory portion of HW4 (compression) is now up on the lectures page of the course site.

    Wednesday, February 24, 2010

    Midterm Review Location

    The midterm review session will be held in WEH 7500 from 2 PM - 4 PM on Sunday Feb. 28.

    Midterm Practice Exam

    A practice exam has been posted in the "lectures" portion of the site, under the entry for Midterm Exam. Please work on this before the review, as we will go over the solutions during the review. Solutions will not be posted, so come to the review if you're interested in the answers.

    Thursday, February 18, 2010

    Midterm Review Session

    There will be a midterm review session on Feb. 28 at 2PM, location TBA. We will be releasing some practice problems soon, and the session will focus on going over those problems and answering general questions.

    Tuesday, February 16, 2010

    Charlie's office hours relocated

    Because Gates 6+ is inaccessible after 6 pm, my regular office hours are now permanently relocated to GHC 4122 or 4126. My regular hours are still Tuesdays from 6 - 7:30 pm.

    Monday, February 15, 2010

    HW 3 programming is now released

    HW 3 is now available on FrontDesk.

    Sunday, February 14, 2010

    HW3 Theory

    HW3 (Seamcarving) theory is up on the lectures portion of the site.

    Saturday, February 13, 2010

    Frontdesk back up

    Frontdesk should be operating normally now (it still might be slow under high load, but you should be able to submit).
    • Homeworks turned in before Thursday 23:59:59 are 0 days late.
    • Homeworks turned in between Thursday 23:59:59 and Saturday 23:59:59 are 1 day even though Frontdesk will say they are 1-2 days late.
    • Homeworks turned in between Saturday 23:59:59 and Sunday 23:59:59 are 2 days late even though Frontdesk will say they are 3 days late.

    Frontdesk Issues

    Due to heavy load and lots of submissions from over 200 students, Frontdesk has run out of disk space and hence cannot process or accept more submissions. The frontdesk maintainer has been alerted and will fix the problem as soon as possible.

    The course staff will discuss and decide how this will affect late days and make an announcement when a decision has been reached. In the meantime (i.e. ASAP) if you ran into submission issues, you'll want to email your submission zip to your TA.

    Tuesday, February 09, 2010

    Updated due dates, office hours

    HW2 theory is now due in lecture Thursday, and the programming portion will still be due Thursday night at midnight. Be sure to check the calendar for updates to office hours in the next couple days. I've rescheduled my office hours tomorrow to noon - 1:30 (during the normal lecture slot) and TAs are rescheduling their office hours as needed without posting an announcement. We hope to have recitation on Wednesday, but this (of course) depends on university policies and the upcoming second snowstorm.

    Monday, February 08, 2010

    No lecture Tuesday

    As you might already know, CMU classes are canceled Tuesday. Check back soon for details of how (and if) this further affects HW2 deadlines this week.

    HW2 theory due in recitation

    To accommodate the snow and office hours changes, the theory portion of HW2 is now due in recitation Wednesday, not in lecture Tuesday. If you miss your recitation or otherwise need more time to complete your homework, you may alternatively turn in the theory portion of your homework to Charlie's office by 4:30 Wednesday. The HW2 programming portion is still due Thursday night as planned.

    Sunday, February 07, 2010

    Office Hour Changes

    Due to the class and office cancellations, Matt M's office hours will be on Tuesday in GHC 4126 from 1:30-3:00pm, and Jeff's office hours will be on Tuesday in GHC 4122 from 7:30pm-9pm.

    Thursday, February 04, 2010

    HW2 Theory Update

    Question 2 of Snake's theory has been revised to specify that a,b cannot equal 1, since logarithms are undefined for base 1. The new versions are available at the same location (under the lectures section of the site).

    Tuesday, February 02, 2010

    Office Hours Change

    Because of the EOC on Thursday, I'm going to have to change my office hours this week to 6:00 PM - 7:30 PM at the Wean 8th Floor Couches.

    Charlie's office hours rescheduled

    I'm sorry for the short notice, but I need to move my office hours from tonight to tomorrow morning: 10 am to noon.

    Saturday, January 30, 2010

    HW2 Theory Released

    You can find it on the lectures page of the portal. The programming part of the assignment will be up on Frontdesk soon (some time today).

    Monday, January 25, 2010

    Worksheet solution

    FYI: The worksheet solution, posted on 20 January of the lecture schedule, has been updated. It includes more formal proofs and shows how to use the alternate Master Method for solving recurrences.

    FrontDesk is back up

    FrontDesk has been up since last night.

    Saturday, January 23, 2010

    FrontDesk problems

    FrontDesk currently is not grading submissions. We're aware of the problem, but don't yet have an estimation for when the problem will be fixed. In the meantime you can still work on the assignment and test your solutions using local unit tests, at least...

    Friday, January 22, 2010

    Office Hours Location Change

    My office hours have moved to GHC4122 (today) due to the closure of Wean. They will still be from 1:30-3:00pm.

    Wednesday, January 20, 2010

    HW1 Update

    Homework 1 has been updated to fix an ambiguity in 1d). The last term is now n instead of O(n). The updated theory questions can be found on the webiso (lectures) portion of the site. Please ignore the version in the stubs.

    Tuesday, January 19, 2010

    HW1 Released

    HW1 has been released. The theory is due Tues, Jan 26 in lecture, the programming is due Thurs, Jan 28 at 11:59pm.

    Saturday, January 16, 2010

    HW 0 is now released

    Remember, the theory questions are due typed in lecture on Tuesday, January 19th. The programming portion of the assignment is due Tuesday, January 19th, at 11:59 PM.

    Sunday, January 10, 2010

    Welcome to 15-211!

    We strongly recommend that you subscribe to this blogger feed and to the course discussion board. We try to send important announcements to this feed, and the information on the course discussion board will greatly help you complete the course assignments.