Algorithms, Probability, and Computing (09)

Lecturers: Emo Welzl (CAB G15.2), with the final chapter on PCP presented by Thomas Holenstein, who will start as a professor at the department October 1st, 2009.
Assistants: Dominik Scheder (CAB G39.1), Martin Jaggi (CAB G33.3), Simone Frau (IFW C45.1)
Time: Monday 13:15-14:00 CAB G11, Tuesday 14:15-16:00 CAB G51; begin: Monday, September 21, 2009
Important: Exercise sessions already start Wednesday, September 16, 13:15, CAB G 56
Credit Points: Informatik Bachelor (252-0203-00L, 3V+2U, 6CP).
Mathematik Bachelor (252-0209-00L, 3V+2U+2A, 8CP) (extra "2A" means additional reading material and special assignments)
Language: English
Contents: Advanced design and analysis methods for algorithms and data structures: Random(ized) Search Trees, Point Location, Network Flows, Minimum Cut, Randomized Algebraic Algorithms (matchings), Probabilistically Checkable Proofs (introduction).
Literature: Notes for every topic will be handed out during the course. Reading assignments are Basics of Probabilistic Analysis for the APC-Lecture. The following textbooks do not cover all topics of the course (neither is every topic treated in these textbooks a topic of the course).
  • Introduction to Algorithms by T. H. Cormen, C. E. Leiserson, R. L. Rivest
  • Randomized Algorithms by R. Motwani und P. Raghavan
  • Computational Geometry -- Algorithms and Applications by M. de Berg, M. van Kreveld, M. Overmars, O. Schwarzkopf
Prerequisites: Basic knowledge of Probability Theory and Theoretical Computer Science as provided by the lectures "Probability and Statistics" and "Theory of Computing" of the Bachelor Programme.

Exams

There will be a written midterm exam and a written final exam. The final exam takes place on Monday, February 8, 2010, 9am-12m in ETA F5 (Gloriastrasse 35)

Grading: Informatik Bachelor (252-0203-00L, 3V+2U, 6CP). There will be a written midterm exam and a written final exam (see below). The grade of the midterm exam amounts to 25% and the grade of the final exam to 75% of the final grade.

Mathematik Bachelor (252-0209-00L, 3V+2U+2A, 8CP). Same procedure as the above variant, plus extra reading material and related special graded assignments handed out during the course. The final grade is composed of the "3V+2U"-component (80%) and the "+2A"-component (20%).
Midterm Exam: November 9, 13:00 (sharp!) - 14:00, CAB G11. Material is everything till November 3. The lecture notes and any other supplementary material for the exam is not permitted. In the week of November 2 there is no new exercise sheet. In the exercise session we will repeat the material of the exam. You are welcome to ask questions related to the material covered and to the course of the exam.
Final Exam: Date and place to be announced (Sessionsprüfung). The lecture notes and any other supplementary material are not permitted for the exam.
Previous Exams: Midterm exam 2007 pdf, midterm exam 2008 pdf, midterm exam 2009 pdf, final exam 2007 pdf, final exam 2008 pdf,
Remarks: For those students who are not able to do the midterm exam because of some crucial reason (military service, etc.) there is the opportunity of a written and oral exam two weeks after the midterm exam.

Every visiting student has to do the midterm exam. If it is however not possible for you to do the final exam there is the opportunity of a written and oral exam one or two weeks before the end of the semester.

ETH students who are at a foreign university during fall have to do a written exam there under supervision and at the same time the exam takes place at ETH.

If any of the reasons above prevent you from taking the exam at the indicated time and location, please inform one of the assistants at the begin of the semester.

Exercises

The weekly assignments are available online Tuesday. The due date is Tuesday the next week.
We recommend that you solve the problems on your own and attend the exercises.
There are three exercise sessions per week:
Nr. Time Place Assistant
1 Wednesday 13:15-15:00 CAB G 56 Simone Frau
2 Thursday 8:15-10:00 CAB G 52 Dominik Scheder
3 Friday 14:15-16:00 CAB G 56 Martin Jaggi

Errata (script)

Contents/Schedule (dates are provisional)

Date
Content
Exercises (with hints)
Mo-Fr, September 14-18 No lectures this week preparation exercises
Random(ized) Search Trees
Mo, 21. September Overview of the course. Introduction and Definitions. Probability for a given binary tree.
Tu, 22. September Depth of the smallest key. Number of leaves. Overall Depth. This exercise sheet will be solved in the exercise classes this week.
These exercises are due on Monday, September 28: 1.7, 1.9, 1.10, 1.14
Mo, 28. SeptemberExpected Height.
Tu, 29. September Depth of Individual Keys. Quicksort. These exercises are due on Monday, October 5: 1.4, 1.17, 1.19, 1.26.
If time permits, we will do some more exercises this week in the exercise sessions
Mo, 5. OctoberQuickselect.
Tu, 6. OctoberRandomized Search Trees: Def. of Treaps, Insertions. Random real numbers. These exercises are due on Monday, October 12: 1.29, 1.36, 1.39, 1.44, 1.45, 1.47
Point Location
Mo, 12. October2-dimensional range queries. Locus approach. Point/Line relative to a convex polygon.
Tu, 13. OctoberLine relative to a convex polygon; reporting, duality, fractional cascading, counting. These exercises are due on Monay, October 19: 2.1, 2.2, 2.3, 2.4, 2.5. There is a hint and a solution for exercise 2.3
Mo, 19. OctoberClosest point in the plane (Post Office Problem).Trapezoidal decomposition.
Tu, 20. OctoberTrapezoidal decomposition (cont'd). These exercises are due on Monday, October 26: 2.6, 2.9, 2.11, 2.16, 2.17
First Special Assignment
The first Special Assignment Problem Set (concerns 3V+2U+2A students only) is online. It is due on Monday, November 16, 2009. You will work with the paper "Randomized Search Trees" by Aragon and Seidel, which can be found here. If this link does not work, please contact us by email.
Maximum Flow
Mo, 26. OctoberResidual graph and augmenting path. Ford-Fulkerson algorithm.
Tu, 27. OctoberProof of the Main Theorem. Capacity Scaling. These exercises are due on Monday, November 2.
Mo, 2. NovemberShortest Augmenting Paths.
Tu, 3. NovemberDinits' Algorithm. Bipartite matchings.
Mo, 9. November Midterm Exam
Minimum Cut
Tu, 10. NovemberIntroduction, Random Contractions, some Bootstrapping
Mo, 16. NovemberBootstrapping. These exercises are due on Monday, November 15
Randomized Algebraic Algorithms
Tu, 17. NovemberChecking Matrix Multiplication. Polynomial Identity Test. Here is the new exercise sheet
Second Special Assignment
The second Special Assignment Problem Set (concerns 3V+2U+2A students only) is online. It is due on Monday, November 30, 2009.
Mo, 23. NovemberTesting for Perfect Bipartite Matchings and Perfect Matchings in General Graphs.
Tu, 24. Novembertba Here is the new exercise sheet
Introduction to PCP
Mo, 30. NovemberDefinition of Approximation ratio. The max-3-SAT problem. Inapproximability (e.g. of MAX-3-SAT). Probabilistic Checkable Proofs.
Tu, 1. DecemberEquivalence of Inapproximability and PCP Here is the new exercise sheet
Third Special Assignment
The third Special Assignment Problem Set (concerns 3V+2U+2A students only) is online. It is due on Friday, December 18, 2009 (just bring it to my office or email it to me). Here is the paper by Stoer and Wagner.
Mo, 7. DecemberLinearity Testing
Tu, 8. DecemberSafe Evaluation
Mo, 14. DecemberProof of Baby PCP.
Tu, 15. Decembertba
Fr, 18. DecemberEnd of Semester