Thursday, November 29, 2007
Tuesday, November 27, 2007
Friday, November 23, 2007
It has come to our attention that there were a few minor errors in Standalone.java and SimpleBoard.java. I have fixed them and and updated the stubs, which you can use to update your code as desired. Also, I fixed up the section on the timers, which was a bit out of date. Sorry if this caused major confusion. Also, if you have questions about anything in the assignment, please check the bboard--Owen and I have been making an effort to clarify things there if they are asked.
Tuesday, November 20, 2007
Monday, November 19, 2007
Saturday, November 17, 2007
The chess server account sign-up page is now up and running. You will need to enter your andrew id, a handle for your chess server account, and a password for your chess server account. This password should not be the password you use for anything else. Your server handle will be shown when you play games, on the ranking site (yet to be activated), and when people see who is online. You should receive a confirmation email (on andrew) after your account has been created. If you have any problems with account creation, email me or Will. http://www.link.cs.cmu.edu/211/sign-up.html
Wednesday, November 14, 2007
The chess assignment should now be completely fixed. If you have any problems with FrontDesk, please email me. I made significant revisions to the assignment from last semester and obviously my testing was not sufficient the first time around. If you already started the assignment you may want to download the stubs again. Sorry for the inconvenience. Hope you have fun completely destroying the bot I wrote when taking the course as revenge!
I incorrectly deployed the chess assignment to FrontDesk. We are working to correct the problem, and it will be fixed tonight. I will make another post to the portal when everything is fixed. There will be no changes to the code you need to implement (some files just need to get moved around and compiled correctly).
For the compression question part c) on the exam: "For a given input, X = x1, x2, x3, ...xn, there is exactly one Huffman tree which will produce a maximal compression ratio." The official answer we graded by was "sometimes" The one instance where there is exactly one tree for the maximum compression ratio is for an empty file (only 1 such tree exists). Since we wrote "x1, x2, x3, ...xn", it is not clear that the length of the file could be 0. So if you wrote "sometimes" or "never" you should receive full credit. If you need a score correction for THIS part of the question, please contact YOUR TA for a score change.
Tuesday, November 13, 2007
Monday, November 12, 2007
Friday, November 09, 2007
We have released the grades for the second midterm on FrontDesk. Both the mean and median on this exam were 64.5% (with a standard deviation of 14.0%). You can pick up your exam from Prof. Scherlis's office starting Monday. We will be devoting a portion of next recitation to going over the midterm, so pick it up before going for your recitation.
Wednesday, November 07, 2007
At the review session students requested additional practice problems on Code Analysis and Dynamic Programming. So here they are: Questions: http://www.cs.cmu.edu/%7E211/content/practice2.pdf Solutions: http://www.cs.cmu.edu/%7E211/content/practice2-answers.pdf If you have not done so already, check out the practice midterm and the recitation material from today. Both of these have more problems on Code Analysis and DP. You can access the recitation material from the "Lectures" tab on the portal.
Handout: http://www.cs.cmu.edu/~211/content/handout-0001.pdf Solutions: http://www.cs.cmu.edu/~211/content/solutions-0001.pdf Slides: http://www.cs.cmu.edu/~211/content/211Rec9-Mid2Review-0001.ppt
Tuesday, November 06, 2007
Saturday, November 03, 2007
We have found that a small but significant number of students are having trouble meeting the deadline for the assignments, so we sat down and figured out a suggested timeline for doing the project. If you are very much behind the schedule we propose, we feel that you might run out of time towards the deadline.
- General Graph - done by the weekend
- Union-Find - done by Wednesday
- Dijkstra - done by Friday evening/Saturday morning
- Kruskal - done by Monday
- Theory + last-minute fixups, additional comments, etc - done before the deadline on Tuesday
Friday, November 02, 2007
There were a number of people who wanted partners for the last assignment, but couldn't find one. If you do not have a partner for the current assignment, and would like one, please post a request on the discussion board. Be sure that you work together; do not simply split up the work. Also, whenever you find that you are having trouble with an assignment you should talk to one of the TAs or the professors about it immediately. There is little we can do if you come to us the day an assignment is due.
Thursday, November 01, 2007
The second midterm will be on Nov 8th. It is in-class and cumulative. Do not bring cell phones, PDAs, computers, or any other such device. Bring your student ID. You may bring a single 8.5"x11" page of notes (both sides). We will be announcing a review session shortly. Please check the portal for the announcement. We will also post an exam from a previous semester so that you have a sense of what to expect. Here is a sample midterm and its solution set.