## Class 27: NP-Complete Desserts

Class 27 slides: [PPTX] [PDF]

In class, someone asked about languages known to be in BQP that are not known to be in NP. There is at least one such language, known as the Recursive Fourier Sampling problem. It is described in this paper: Quantum complexity theory by Ethan Bernstein and Umesh Vazirani, ACM Symposium on Theory of Computing, 1993. [Full version: PDF] Section 8.4 of this paper describes the problem, but it [More...]

I have uploaded your scores on assignments into Collab so you can now verify that I have all your scores recorded correctly. If you notice any discrepancies, please let me know.

## Class 26: NP-Complete Entrees

Class 26 slides: [PPTX] [PDF]

## Class 25: NP-Complete Appetizers

Class 25 slides: [PPTX] [PDF]

Since I badly messed up the reduction from SUBSET-SUM to KNAPSACK, and don’t see an obvious way to fix this, you can solve this question in place of Problem 5 on PS6. If you get an especially elegant and convincing answer that you would like to present in class Tuesday, send it to me by Monday afternoon.

The reading handed out today is available here: The Status of the P versus NP Problem, [More...]

## Class 24: NP-Completeness

Class 24 slides: [PPTX] [PDF]

## Problem Sets 6 and 7

Problem Sets 6 and 7 are now posted. Problem Set 7 is quite different from all the other problem sets. Although it is not due until the last day of class, I strongly encourage everyone to read it now (only one page) and start thinking about what you want to do for it. You do not need to wait until you finish PS6 to start PS7 (and I would recommend starting on it earlier).

Problem Set 6: [PDF] [More...]

## Class 23: P = NP?

Class 23 slides: [PPTX] [PDF]

## Is the BLEND Problem Blender-Decidable?

[Larger Image]
[Hat tip to Michael Chen]

## Class 22: Introducing Complexity

Class 22 slides: [PPTX] [PDF]

The next reading assignment is Sipser, Chapter 7. (We are skipping Chapter 6.)

Problem Set 6, originally scheduled to be due on April 20th on the syllabus, will now be due on April 27 (and will be posted soon).

## Exam 2

Exam 2 is here: [PDF] [LaTeX Template]

Exam 2 is due at the beginning of class Tuesday.

## Class 21: Undecidability in Theory and Practice

Class 21 slides: [PPTX] [PDF]

## No Office Hours Tomorrow!

I wonâ€™t be holding office hours tomorrow. Good luck with your exams!

## Class 20: Busy Beavers

Class 20 slides: [PPTX] [PDF]

## Thursday office hours

Sorry, I will not be able to hold my usual Thursday morning this week. Instead, I will have office hours Thursday 11am-1pm.

## Student Council Technology Committee

Kate McDowell is looking for students to join the Technology Committee of the Student Council, which she is chairing next year.

They are looking for students with a passion for technology, and all majors and experience levels are welcome. Projects will include:

• Managing www.uvastudentcouncil.com
• Maintaining SpeakUpUVA
• Livestreaming StudCo meetings on the web
• Finding creative new ways to use technology

To apply, visit http://www.uvastudentcouncil.com. Contact Kate McDowell (kam6zx) for details.

## Tuesday's Class, Preparing for Exam 2

Exam 2 will be handed out Thursday, April 8 and due Tuesday, April 13. It will cover everything through today’s class (Barbara Liskov’s lecture), but emphasize things that have been covered since Exam 1: class 10-18, Problem sets 4 and 5.

If you have any topics you would like me to review in class Tuesday, or questions you want me to go over, please post them here.

As a separate game theory challenge, if exactly ONE student in [More...]