CMPSCI 311: Theory of Algorithms

David Mix Barrington

Fall, 2003

This is the home page for CMPSCI 311. CMPSCI 311 is the undergraduate core course in the theory of algorithms and will deal with methods of analysis, algorithmic paradigms, and algorithms for sorting, searching, graph problems, numerical problems, and other problem domains. We will conclude with a brief look at NP-completeness and approximation of NP-complete optimization problems.

Important Course Material:

• Instructor/TA Contact and Office Hour Info
• Discussion Notes Directory
• Homework Assignment Directory (with HW#9)
• Exam Directory (with final and solution)
• Questions and Answers
• Syllabus (now complete)
• Honors Section

Announcements (21 December):

(21 Dec) I just fixed the link to the solutions below.

(19 Dec) I've posted the final and its solution. I am making good progress with the grading and should be able to file grades and answer the many email requests on Monday, when I should get the HW9 grades. HW#8's, Discussion #8's, and Discussion #10's are available in the main office.

(14 Dec) Jeff has posted solutions to HW#9.

(12 Dec) The practice final solutions have been posted. I made some edits to the practice final last night -- you may want to redownload it if you've downloaded it already.

(12 Dec) Jeff hopes to post HW#9 solutions late tomorrow.

(12 Dec) I will be answering email through the weekend as I grade backed-up discussions, and will be in my office for most or all of the day on Monday and Tuesday before the exam at 4:00.

(8 Dec) There was a mistake in the point values of the HW#9 questions, which has now been corrected.

(5 Dec) I've just posted the HW#9 assignment.

(3 Dec) I have just posted notes and solutions from today's discussion.

(1 Dec) I hope you had a pleasant holiday. I've just posted the notes and solutions for Discussion #10. Sorry for may delay in doing this. Make sure you understand the solution to the last question, which I used today in lecture as an example of a reduction.

(1 Dec) I still have not graded Discussion #8 or #10, sorry.

(23 Nov) I have just posted the HW#8 assignment. It is due a week from Friday, after the break.

(23 Nov) I will be out of town and away from email from Tuesday morning 25 November through Saturday night 29 November. My best wishes for a happy holiday!

(20 Nov) I've just posted several questions and answers on HW#7.

(15 Nov) The Homework #7 assignmnent is now posted.

(13 Nov) The syllabus has finally been updated to reflect the entire semester. There will be a few topics not in the book, such as the network flow problem from last (and next) discussion and more on NP-completeness. I recognize that I now owe you three graded discussions. Note again that although the University is open on Wed 26 November, the day before Thanksgiving, I am cancelling both the lecture and discussion for that day.

(11 Nov) The exams were somewhat disappointing, though I know time pressure was a factor. I have set the scale at 85 for the middle of the A range and 55 for the middle of the C range. The count at each grade level:

• A+ (89-100): 3 (highs were 95, 93)
• A (82-88): 5
• AB (74-81): 14
• B (67-73): 6
• BC (59-66): 15
• C (52-58): 10
• CD (44-51): 9
• D (37-43): 6
• F (0-36): 6
• (10 Nov) The second exam and its solution are up. I've started grading them -- it looks like I may slide the scale a bit in your favor. The fact that no one left early suggests to me that it was too long. But we will see.

• (10 Nov) I will post the remainder of the syllabus, probably tomorrow, but I can announce already that there will be no lecture and no discussion on Wed 26 November, the day before Thanksgiving.

• (10 Nov) Graded HW#5's were returned at the exam, if you did not get yours check the CMPSCI main office pickup box.

• (6 Nov) The practice exam solution is up.

• (5 Nov) I have just posted notes and solutions for today's discussion, which was Discussion #8. I handed back graded Discussion #6 in lecture this morning, so I remain only two discussions behind. If you did not pick up #6 in lecture you may get it from the box in the CMPSCI main office.

• (3 Nov) The practice exam for the second midterm is now posted. It is probably a little longer than the real midterm will be. I'll post solutions to this Thursday.

• (3 Nov) There is no assigned homework on Chapter 7, but you may find the following problems to be useful guides to your study: 6.6.2, 6.6.5, 6.6.9, 6.6.10, 7.2.2, 7.2.6, 7.3.3, 7.3.4, 7.3.7, 7.4.4, 7.4.5. I had hoped to post solutions to these problems before the exam but unfortunately never got to it, sorry.

• (30 Oct) There are now some questions and answers on HW#6.

• (29 Oct) Notes and solutions for Discussion #7 are now posted. I handed back graded HW#4 today in class, I still haven't graded Discussion #6.

• (29 Oct) The second midterm is a week from Monday. As with the first midterm, there will be no homework due during the week before the exam, but I will provide some practice problems and solutions to them. I'll post a practice exam, probably on Monday 3 November.

• (24 Oct) The HW#6 assignment is now posted.

• (23 Oct) There are now some questions and answers on HW#5.

• (22 Oct) Notes and solutions for Discussion #6 are now posted.

• (17 Oct) The HW#5 assignment is now posted. I handed back discussion #4 today -- those not claimed are in the pickup box in the office. I'll try to get discussion #5 back on Monday.

• (16 Oct) There are now some questions and answers on HW#4 posted.

• (10 Oct) The HW#4 assignment is finally posted, sorry for the delay.

• (10 Oct) Remember that there is no class Monday 13 October, and no discussion on Wednesday 15 October because we have a Monday schedule. Enjoy your weekend! Go Red Sox!

• (9 Oct) Notes and solutions for Discussion #5 are now posted.

• (6 Oct) I handed back graded midterms and HW#3's today in lecture. If you did not get your HW#3 you may get it from the pickup box in the CMPSCI main office. The exams, on the other hand, you may only get from me (in lecture or discussion class Wednesday, unless you happen to catch me in my office). This is out of respect for your privacy -- I don't mind leaving graded HW or discussions to be pawed over in a public place but graded exams should be more private than that.

  Most of you did reasonably well on the exams. I am moving the scale down only slightly from what I said on the exam sheet, so the middle of the A range will be 93 and the middle of the C range 63. The count at each grade level:

  • A+ (97-100): 5
  • A (90-96): 12
  • AB (82-89): 12
  • B (75-81): 11
  • BC (67-74): 11
  • C (60-66): 11
  • CD (52-59): 7
  • D (45-51): 5
  • F (0-44): 2

• (4 Oct) The exam and its solution are now posted.

• (2 Oct) I've updated the syllabus to cover the middle third of the course.

• (2 Oct) The notes and solutions to yesterday's discussion are now posted. I made some changes in the text of the notes to reflect clarifications and corrections made during the discussion meeting.

• (1 Oct) I have posted solutions to the suggested Chapter 4 problems here.

• (1 Oct) We've had some logistical problems with returning the graded HW#2's, for which I apologize. There are still some 8-10 papers that I didn't have to hand out at either lecture or discussion today, but they do exist and should be in the pickup box in the main office by 5:00 today. Of course, if we've actually lost a paper, which it doesn't appear yet that we have, we'll make sure the student isn't penalized.

  (1 Oct) By the way, the discussion today will be new material rather than a review for the exam. I expect most of Jeff's and my office hours for the rest of the week will be taken up by exam review.

  Some students were disappointed by the lack of grader feedback on HW#2. Since there are detailed solutions available on Jeff's web site, feedback consists mostly of the number telling you how right you were and some indication of which parts of your answer was wrong. If, after comparing your answers to the solutions carefully, you have questions about the grading, email Jeff who will refer them to the grader.

  I haven't decided the HW#2 scale yet -- a guess is 88=A, 60=C.

• (1 Oct) The practice exam solution is posted.

• (27 Sept) There will be no homework specifically on Chapter 4 of Levitin. However you might find it useful to look at problems 4.1.3, 4.1.10, 4.2.2, 4.2.8, 4.2.10, 4.3.3, 4.3.5, and 4.3.10 as you study for the midterm.

• (27 Sept) The practice midterm is up.

• (26 Sept) We have the first midterm a week from today. Note that HW#4 will not be assigned until after the midterm.

• (26 Sept) Homework solutions are available on Jeff's CS311 web site.

• (22 Sept) Graded Discussion #2's are being handed back in class today. I was generally pleased with them -- along with the 23 "check-plus" grades I gave for getting four or more right (only one person got all six right), there were a large number who got the first three right with very clear writeups. As always, see the solutions for anything you missed, because you will be responsible in the future for knowing how to do these problems.

• (17 Sept) The assignment and solution for today's discussion are now posted. Also, graded HW#1 papers were returned after the discussion period. (I hope you were as pleased and impressed as I was with the quick turnaround.) The scale for HW#1 was A=92, C=64.

• (15 Sept) Graded Discussion #1's were handed back in lecture today. I'll put the remaining ones in a box in the CMPSCI main office tomorrow. Also, there are now two answered questions about HW#2.

• (10 Sept) I have posted the discussion assignment and solutions in the discussion notes directory. Don't panic if you weren't able to do all four of the proofs. The question to ask yourself is whether you could do four similar proofs in an hour next week after reviewing what you need to review. Of course I won't ask you to do that, as we'll do something new instead. What I like about this discussion format is that it forces you to confront what you need to confront without (much of) a grad penalty for not being able to do it right off.

• (10 Sept) Jeff's office hours take place in LGRT 220.

• (8 Sept) Jeff Johns, our TA, has set up a web site for this course. His office hours are Monday 11:15-12:15 and Thursday 11-1, in LGRT 220 near the EdLab. Mine are Wednesday 1:15-2:30 and Thursday 9-11 in my office. I said "Wednesday 9-10" in lecture and on an earlier version of this announcement, but I changed my mind.

• (8 Sept) There are now a couple of HW#1 questions answered on the Q&A page.

The textbook for the course is a new one, Introduction to the Design and Analysis of Algorithms by Anany Levitin (Addison-Wesley, ISBN 0-201-74395-7). I have ordered copies through the Jeffrey Amherst College Store in downtown Amherst.

Last modified 21 December 2003