Exam Histogram

Here's a posting of the histogram for the final exam. On the 211 portal it doesn't always show up, so click on Older Posts and it will.

Recitation 15: Game Trees

(pdf)

Approximate curve

If you want to get a rough estimate of your current standing in the class, do the following: Take your grades for the 4 quizes, the two midterms, and the first 5 homeworks (i.e., everything but chess). The weights are currently as follows: each quiz has weight 1, each exam has weight 3, helloWorld=1, expression tree=2, snakes=2.5, compression=3, graphs=2.5. Compute your weighted average. A weighted average of 84.8, or higher is an A, 78.2, to 84.7 is a B, 67.3 to 78.1 is a C, 53.9 to 67.2 is a D, and everything else is failing. This is not the official curve, only an estimate. There is the final, of course, we are still grading chess, we will be dropping the lowest quiz grade, and the TA will allocate discretionary points, based on your participation in recitations.

Office Hours Change

Due to final exams, I am changing my Thursday office hour to 4:30 in Wean 3130.

Review Session

The review sessions will be in WeH 7500 from 6-8 PM on Wednesday. Please come with specific questions as it is impossible to cover everything.

Lecture 28: Correctness

Slides: (pdf)

Lecture 25: Concurrency

Slides: (pdf)

Practice final exams

We added practice final exams under the lectures tab.

Practice final exams

Practice exams. practice.zip. Some have solutions, some do not; some have a clean version and a solution set, some are only a solution set. These are all we have, do not ask for more, or for us to make changes.

Extra Office Hours

I'll have extra office hours again on Friday (Nov. 8) for those who want help with chess from 1-2 PM in WeH 3130.

Update on review session

We are now considering moving the review session for the final to 6-8pm on the 13th, due to various scheduling conflicts. We will make a final announcement on the review within the next week.

Lecture 27: Order statistics

Slides (pdf)

Review for the final

We are considering holding the review session for the final on Dec 13th, from 3-5pm. The 13th is a reading day. Please email me (Chris) if you cannot attend that time.

Extra Office Hours

I'll have extra office hours tomorrow for those who want help with chess from 1-2 PM in WeH 3130.

Lecture 26: Linear time sorting

Slides: (pdf)

Lecture 24: Game search part 2

Slides: (1st half of lecture) (2nd half of lecture)

Late Day Policy for Chess

The deadline will be extended 3 more days until Sunday (Dec. 10) for everyone regardless of how many late days you have left.

Ryan and Vinay are switching office hours

Same times, different people.

Today's lecture: FSMs, part 2

Please bring the handout from the first FSM lecture. --Bill

Second midterm

The 211 staff want to acknowledge that the second midterm exam was very difficult. It is fair to say that some of the questions were more suited to an advanced course. As a remedy, we will reweight the exam and post the grades to FrontDesk. In the next few days we'll compute new overall grades and post them on FD so you can see how you are doing in this new regime. --Bill, Chris, and your loyal TAs

Exams are graded

The exams are graded, and can be picked up outside Prof. Scherlis' office between 7:30 and 3:30 pm. The mean grade was a 62/140 and the median was a 59/140. As a reminder, there will be a curve. We have not figured out what the curve is. However, if you want a rough estimate (and this is only an estimate), C's will start somewhere around 42/140, B's somewhere around 55/140, A's somewhere around 80/140. The TAs will go over the exam next recitation.

Extra Office Hours

I'll have extra office hours today (Wednesday) and be in WeH 3130 from 5:30-6:30.

Videos

Lect 21 game trees link

Lect 20 sorting link

Lect 19 FSM 1 link

Lect 18 dyn prog 2 link

Lect 17 dyn prog 1 link

Lect 16 string search link

Lect 15 graphs 3 link

Lect 14 graphs 2 link

Lect 12 graphs 1 link

Lect 11 compression link

Lect 10 tries skip lists link

Lect 9 stack link

Lect 8 heap link

Lect 7 hash link

Lect 6 trees 2 link

Lect 5 trees 1 link

Lect 3 list link

Lect 2 union find link

Lecture 19 FSM

Slides: (pdf)

Lecture 16 string matching

Slides: (pdf)

String matching and FSMs WON'T be on the exam

Since the lecture notes haven't been put up, the exam will not include questions on those two topics. Note that dynamic programming questions regarding strings are still possible.

Lecture 21 Game Trees

Slides: (pdf)

Sample midterm

A sample midterm can be found here

Jon's Office Hours Cancelled

Due to the midterm exam, I am cancelling my office hours on Thursday.

Midterm and Midterm review

The 2nd midterm is on Nov 9th. It is in-class. You may bring one page of notes (both sides). The exam is closed book and no electronic devices may be used. We will have a review for the midterm on Nov 7, 6-8pm, in Porter Hall 100 (see directions below). Please post requests for topics you would like to see covered during the review session to the discussion board. Directions: 1. Walk across the 5th floor Wean Hall Patio 2. Go into the door directly across from us on the patio level. That's the entry to Porter Hall. 3. Wall down the hallway until you see the staircase on your right. 4. Go up one floor to the first floor of Porter Hall. 5. Turn left and go down the hallway almost to the doorway on Frew Street. 6. Before the doorway, turn left, that is where the review will be held.

Lecture 20 Sorting

Slides: (pdf)

Hao's Office Hours Changed

Hao is changing his regular Monday office hours from 2-3 to 1-2 on Monday.

Lecture 18 Dynamic Programming 2 (Bellman-Ford)

Slides: (pdf)

Quiz in recitation next Wed

Recitation 9: Dynamic Programming

(pdf)

Recitation 8: Dijkstra's Algorithm

(pdf)

Lecture 17 Dynamic Programming

Slides: (pdf)

Extra Office Hours Monday 9:00 P.M - 10:30 P.M

Since I've had a few requests, I'm holding extra office hours Monday night from 9-10:30 P.M in Wean 3130.

There is no lecture 12

We held the 1st midterm on what would have been lecture 12.

Lecture 15 Graphs, part 3

Slides: (pdf)

Recitation7: LZW and Huffman Headers

(pdf)

Recitation 6: Huffman

(pdf)

Lecture 14 Graphs, part 2

(pdf)

Lecture 13: Intro to graphs

(pdf)

Exams are graded

The exams can be picked up after 2pm on Friday in Wean Hall 5220 (Prof Scherlis' office suite). Update, 3:10p: You can see your grades in FrontDesk.

We have not yet figured out a curve for the exam. So it is difficult to say, at this time, which scores are A', B's, and so forth. FYI: the median score was an 88 and the mean was an 87 (out of 138)

Lecture 8: Priority Queues and Heaps

(pdf)

Lecture 11: Compression

(pdf)

Jon's Office Hours Cancelled

Due to the midterm exam, I am cancelling my office hours on Thursday.

Recitation 5: Hashing and Quiz Review

Slides: (pdf)

Practice exams

We have posted a practice midterm here . Here are the solutions.

Midterm Review

The review for the midterm is Oct 3, 6-8pm, in Wean Hall 7500. Please post requests for topics you would like to see covered during the review session to the discussion board.

Using Late Days

To use a late day in FrontDesk, just submit late. FrontDesk will keep track of your status.

Lecture 10: Tries and Skip Lists

Slides: (pdf)
Video: CourseCast

Homework 2 Deadline Extended

The deadline for the snake lab has been extended until Saturday, September 30 at 11:59 PM. Enjoy!

Lecture 9: Queues

Slides: (pdf)
Video: CourseCast

Will's Office Hours Cancelled

I am going to have to cancel my office hours this Thursday because I will be out of town. I just wanted everyone to know before they made plans to attend.

Tip: Submit Early & Often

Help FrontDesk help you by submitting your homework early and often. There is no penalty for making submissions before you've fully completed the assignment. In fact FrontDesk has features that specifically target early submissions:

• When evaluating JUnit tests, FrontDesk only considers how well you test the code that you have written. If you've only written the Queue, we'll only hold you accountable for tests on that class.
• FrontDesk targets the tests it shows you to how far along you are. If you haven't started the HashSet, but have worked on Queue, FrontDesk will show you exceptions in the Queue class.

Submitting early is a great way to get early feedback on how you are doing, evaluate the strength of your unit tests, and harness the automated bug finding power of FindBugs. Submitting early is a great way to help your TA help you. TAs are able to see your submissions, so asking a question about your code is as easy as talking to your TA via email or in office hours.

Recitation 4: Iterators and Splay Trees

Slides: (pdf)

Snake Help Session: Sunday

We're running a help session for snake on Sunday from 7-9pm in the Wean Hall Linux clusters. To make the most effective use of your time, start the homework before the session starts, and then come with questions.

HW 2 is out

Homework 2 is on Frontdesk

Lecture 7 and 8: Hashing

Slides: (pdf)
Video: Lecture 7 CourseCast Lecture 8 CourseCast

Recitation 3: Asymptotic Analysis and Recurrences

Slides: (pdf)

Lecture 6: Trees 2

Slides: (pdf)
Video: CourseCast

Lecture 5: Trees 1

Slides: (pdf)
Video: CourseCast

Lecture 4 notes are up

Hi, I've put the notes for lecture 4 (analysis of algorithms) up. They are slightly different than the ones handed out in lecture. In particular, they correct an error on the last 4 slides on the intuition behind the master method. The amount of work done per level is a^i*f(n/b^i) at the i'th level in the tree. The notes handed out in class incorrectly listed the amount of work as a^i*f(n). Sorry for the confusion. I will go over this briefly in class on Tuesday.

Lecture 4: Analysis of Algorithms

Slides: (pdf)

Reciation 2: Debugging

Slides: (pdf)

Lecture Slides Posted

We've posted slides for the first three lectures and the first recitation in the Lectures section. Sorry for the delay.

Lecture 3: Lists, mutability, representations

Slides: (pdf)
Video: CourseCast

Lecture 2: Union Find

Slides: (pdf)
Video: CourseCast

Recitation 1: Infrastructure / Abstract Classes

Slides: (pdf)

Lecture 1: Welcome

Slides: (pdf)

Homework 1 Released

Homework 1 is released. Go to Assignments to see it.

Welcome to 15-211

We're glad to have you in 15-211 this semester! In order to get you started, we have created a list of places you should look at in the course portal.

1. This is the announcements area. You'll want to keep on top of announcements by either visiting the course portal or subscribing to the news feed.
2. To the right of the announcements area is a course calendar. In addition to posting the lecture schedule, we'll post review sessions, office hours and other events that you might be interested in. Consider using the iCal feed to keep on top of this.
3. Below the calendar is a sampling of recent discussion board posts. You should subscribe to this so that you can search for answers and post questions. Clicking Older Posts will get you to the discussion board interface from which you can subscribe.
4. To the left of the announcements area is a list of links. You should read the course policies and course information links.
5. In the list of links is a Get Started guide. This will help you set up your programming environment and guide you through a sample assignment. Completion of this is required. The sample assignment is intended to help you get familiar with the infrastructure, so you can focus on the content of the course in later assignments.