CSCI5010: Practical Computational Geometry Algorithms

Spring 2021

Professor: Yufei Tao
TA: Shangqi Lu

Quick links:
[Zoom Links][Lecture Notes][Exercises]

Brief Description

This course will discuss data structures and algorithms for solving with good theoretical guarantees fundamental geometry problems that have significant importance in computer science. Topics covered include convex hulls, maxima, planesweep, polygon triangulation, linear programming, minimum enclosing circle, point location, voronoi diagrams, delaunay triangulation, closest pair, orthogonal range searching, and so on.

Announcements

21. (28 Apr) The Zoom link for the final exam is https://cuhk.zoom.us/j/94990226997.

20. (20 Apr) Exercise list 12 released.
19. (13 Apr) Exercise list 11 released.

18. (31 Mar) Quiz 3 will take place in the lecture of Apr 12. The scope covers Topics 10-11. The questions will be released at the beginning of the quiz. You need to submit your solutions to the Blackboard system within 15 minutes.

17. (31 Mar) Exercise list 10 released.
16. (28 Mar) Exercise list 9 released.

15. (16 Mar) Quiz 2 will take place in the lecture of Mar 22. The scope covers Topics 8-9. The questions will be released at the beginning of the quiz. You need to submit your solutions to the Blackboard system within 15 minutes.

14. (16 Mar) Exercise list 8 released.
13. (9 Mar) Exercise list 7 released.

12. (1 Mar) The midterm exam will take place in the lecture of 9 Mar. The scope covers everything in Topics 1-7 and Exercise Lists 1-6. The questions will be released at the beginning of the exam. You need to submit your solutions to the Blackboard system within 45 minutes.

11. (1 Mar) Exercise list 6 released.
10. (9 Feb) The final exam will be held on Apr 29, from 3pm to 5pm.
9. (9 Feb) Exercise list 5 released.
8. (26 Jan) Exercise list 4 released.

7. (1 Feb) Quiz 1 will take place in the lecture of Feb 8 (Week 5). The scope covers everything in Topics 1-3. The questions will be released at the beginning of the quiz. You need to submit your solutions to the Blackboard system within 15 minutes.

6. (1 Feb) The tentative schedule of the quizzes and the midterm:
  • Quiz 1: 8 Feb (Week 5)
  • Midterm : 9 Mar (Week 8)
  • Quiz 2: 22 Mar (Week 10)
  • Quiz 3: 12 Apr (Week 12).
5. (26 Jan) Exercise list 3 released.
4. (25 Jan) Exercise list 2 released.
3. (19 Jan) Exercise list 1 released.
2. (11 Jan) Today's lecture and whiteboard picture have been uploaded to the Blackboard system. There will be no future announcements about such uploads. Please check the system after each lecture.
1. (10 Jan) Hello all.

Time and Zoom Links

Monday 10:30am - 12:15pm, Zoom Link
Tuesday 10:30am - 11:15pm, Zoom Link

Grading Scheme

Quiz 1: 10%
Quiz 2: 10%
Quiz 3: 10%
Midterm: 25%
Final Exam: 45%

Textbook and Lecture Notes

The instructor recommends the following textbook:
M. de Berg, M. van Kreveld, M. Overmars, O. Schwarzkopf. Computational Geometry: Algorithms and Applications.

Book ownership is optional. The following lecture notes contain most of the course's content:
Lecture Notes (thanks to Dave Mount).
Additional material will be provided by the instructor.



Topic 0: Computation Model

Topic 1: Convex Hulls
Reading: Lec 3 of Dave's notes.
Extra reading: Textbook Chapter 1.

Topic 2: Output-Sensitive Maxima

Topic 3: Planesweep 1 - Segment Intersection
Reading: Lec 5 of Dave's notes.
Extra reading: Sec 2.1 of the textbook.

Topic 4: Planesweep 2 - Polygon Triangulation
Reading: Lec 6 of Dave's notes.
Extra reading: Chapter 3 of the textbook.

Topic 5: Dimensionality Reduction 1 - Maxima

Topic 6: Dimensionality Reduction 2 - Rectangle-Point Containment
Old version of the notes (changes: see Slides 4, 10, and 11 of the new version)

Topic 7: Point Location
Reading: Lec 26 of Dave's notes.

Topic 8: Backward Analysis 1 - Linear Programming
Reading: Lec 7 of Dave's notes.
Extra reading: Sec 4.1-4.6 of the textbook.

Topic 9: Backward Analysis 2 - Minimum Enclosing Disc
Extra reading: Lec 23 of Dave's notes and Sec 4.7 of the textbook.
Old version of the lecture notes (error: Lemma 3 statement)

Topic 10: Voronoi Diagram (and Nearest Neighbor Search)
Reading: Lec 11 of Dave's notes (you may ignore the planesweep algorithm).
Extra reading: Sec 7.1 of the textbook.

Topic 11: Backward Analysis 3 - Delaunay Triangulation
Reading: Lec 12-13 of Dave's notes.
Extra reading: Sections 9.1-9.4 of the textbook.

Topic 12: Grid Decomposition - Closest and Close Pairs
Extra reading: Lec 33 of Dave's notes.

Topic 13: Point-Plane Duality and Line Arrangements
Reading: Lec 2, 8, 14, and 15 of Dave's notes.
Extra reading: Chapter 8 of the textbook.

There will be no more lectures.

Exercises

Some midterm/final exam problems will be taken almost directly from the exercise lists below. No solutions to these exercises will be given. You, however, are welcome to present your solutions to the instructor; he will tell you whether the solutions are correct.

Exercise List 1
Exercise List 2
Exercise List 3
Exercise List 4
Exercise List 5
Exercise List 6
Exercise List 7
Exercise List 8
Exercise List 9
Exercise List 10
Exercise List 11
Exercise List 12
There will be no more exercises.