Course: Special topics on graph algorithms

Spring semester, 2024

9:10 - 12:10 Tuesday, 105 CSIE Building.

3 credits

Web site: http://www.csie.ntu.edu.tw/~kmchao/tree24spr

Instructor: Kun-Mao Chao (趙坤茂)

TA: Pin-Chun Huang (黃品淳)  r11922135 followed by @ntu.edu.tw
[TA's office hours: by appointment; Venue: R432]

 

Prerequisites: Some basic knowledge on algorithm development is required. Background in approximation algorithms is welcome but not required for taking this course.

 

Please follow the NTU guideline for course selection. (Sorry that it's hard to reply to every enquiry email during the hectic season.)

https://www.aca.ntu.edu.tw/WebUPD/acaEN/UAADForms/112-2selcou-eng.pdf

 

* A set of sample problems for Midterm Exam. #1 was announced via NTU COOL on March 20, 2024.

* Selected papers for presentation have been posted on April 2, 2024.

* Midterm #1's score histogram (updated on April 15, 2024)

* Presentation schedule now available (4/16/2024)

* No class on April 23, 2024.

 

Coursework:

Two midterm exams (35% each; tentatively on Mar. 26, 2024 and May 7, 2024)

Oral presentation or implementation of selected topics or papers (20%)

Homework and class participation (10%)

 

Our classmates: I II III IV V VI

 

Lecture notes:

       Introduction [2/20/2024]

       Counting spanning trees [2/20/2024]

               Slides [2/20/2024]      

               The number of unlabeled spanning trees of $K_n$ [2/20/2024]

               A bijection between labeled trees and Prüfer sequences by Prof. David Galvin [2/20/2024]

       Minimum spanning trees [2/20/2024]

               Slides [2/20/2024]

               2-approx. for TSP with triangle inequality [2/20/2024]

       Shortest-paths trees [2/27/2024]

               Slides [2/27/2024]

       A note on a 2-approximation algorithm for the MRCT problem [2/27/2024]

               MRCT_slides [2/27/2024, 3/19/2024]

               2-approximation_algorithm_slides [2/27/2024, 3/5/2024]

               Examples: I  II  III [2/27/2024]

       A note on 15/8 & 3/2-approximation algorithms for the MRCT problem [3/5/2024]

               Slides [3/5/2024, 3/12/2024]

               Bounds for the routing load of a minimal separator [3/5/2024]

       (4/3+epsilon)-approximation: Approximation Algorithms for the Shortest Total Path Length Spanning Tree Problem

               Slides [3/12/2024, 3/19/2024]

       A note on a polynomial time approximation scheme for the MRCT problem (More details) [3/19/2024, 4/2/2024]

               The reduction to the metric case [3/19/2024, 4/2/2024]

               The PTAS for the MRCT problem (A rough estimate for a delta-path) [4/2/2024]

               Finding an optimal k-star [4/2/2024, 4/9/2024]

       Optimal communication spanning trees [4/9/2024]

       A 2-approximation algorithm for the SROCT problem [4/9/2024, 4/16/2024]

               Slides [4/9/2024, 4/16/2024]

              (Note: S. V. Ravelo, C. E. Ferreira: A PTAS for the metric case of the minimum sum-requirement communication spanning tree problem. Discrete Applied Mathematics 228: 158-175 (2017))

       A note on the eccentricities, diameters, and radii [4/16/2024]

               Slides [4/16/2024]
               An example showing that the farthest vertex of any vertex may not lie in the diameter [4/16/2024]

               Graph Theory: 51. Eccentricity, Radius & Diameter by Sarada Herke [4/16/2024]

       Steiner minimal trees

               Slides

              (Note:
                        N. Innami, B. H. Kim, Y. Mashiko, K. Shiohama: The Steiner Ratio Conjecture of Gilbert-Pollak May Still Be Open. Algorithmica 57(4): 869-872 (2010)

                        Alexandr O. Ivanov, Alexey A. Tuzhilin: The Steiner Ratio Gilbert-Pollak Conjecture Is Still Open - Clarification Statement. Algorithmica 62(1-2): 630-632 (2012))
       A note on the uniform edge-partition of a tree

               Slides

              (Note:

                        Bang Ye Wu, Hung-Lung Wang, Shih Ta Kuan, and Kun-Mao Chao: On the uniform edge-partition of a tree. Discrete Applied Mathematics 155(10): 1213-1223 (2007)

                        An-Chiang Chu, Bang Ye Wu, and Kun-Mao Chao: A linear-time algorithm for finding an edge-partition with max-min ratio at most two. Discrete Applied Mathematics 161(7): 932-943 (2013))

       A note on the minimum spanning tree cycle intersection problem

              (Note:

                        M. Dubinsky, C. Massri, and G. Taubin. Minimum spanning tree cycle intersection problem. Discrete Applied Mathematics, 294:152, 2021.

                        M.-J. Chen and K.-M. Chao. Proof of a conjecture about minimum spanning tree cycle intersection. Discrete Applied Mathematics, 321:19, 2022.)

 

Class presentations:

1.      Suggested number of team members: 1~5

2.      Each member is required to present in turn [about 10~12 minutes each; roughly 150/(the number of speakers on the same day) minutes each];

3.      Revised slides should be sent to me within one week after the presentation;

4.      Questions in class are always welcome.

 

May 14, 2024

Shang-En HuangDawei HuangTsvi Kopelowitz, Seth Pettie, Mikkel Thorup:
Fully Dynamic Connectivity in O(log n(loglog n)2) Amortized Expected Time. TheoretiCS 2 (2023)
劉宇倫  蘇子碩  陳建宏  譚雋飛  趙容

 Jesper JanssonWing-Kin SungSeyed Ali TabatabaeeYutong Yang:
A Faster Algorithm for Constructing the Frequency Difference Consensus Tree. STACS 2024: 43:1-43:17
MARIA CAROLINA CORNELIA WIT and
PINTUSORN SUTTIPONPISARN

 Subhash Bhagathttps://dblp.uni-trier.de/img/orcid-mark.12x12.pngAndrzej Pelc:
Deterministic rendezvous in infinite trees. Theor. Comput. Sci. 984: 114313 (2024)
吳政宏

 

Miguel LiconaJoaquín Teyhttps://dblp.uni-trier.de/img/orcid-mark.12x12.png:
Conservative trees. Discret. Math. 347(3): 113854 (2024)
周昱宏  蔡莉亞  陳怜均

 

Samuel Thomashttps://dblp.uni-trier.de/img/orcid-mark.12x12.pngKidus Worknehhttps://dblp.uni-trier.de/img/orcid-mark.12x12.pngAnge-Thierry Ishimwehttps://dblp.uni-trier.de/img/orcid-mark.12x12.pngZack McKevitthttps://dblp.uni-trier.de/img/orcid-mark.12x12.pngPhaedra S. Curlinhttps://dblp.uni-trier.de/img/orcid-mark.12x12.pngR. Iris Baharhttps://dblp.uni-trier.de/img/orcid-mark.12x12.pngJoseph Izraelevitzhttps://dblp.uni-trier.de/img/orcid-mark.12x12.pngTamara Lehmanhttps://dblp.uni-trier.de/img/orcid-mark.12x12.png:
Baobab Merkle Tree for Efficient Secure Memory. IEEE Comput. Archit. Lett. 23(1): 33-36 (2024)
CASSANDRA LE PADELLEC and PAUL FEICHTENSCHLAGER

 

-----------

May 21, 2024

 Rahul Jainhttps://dblp.uni-trier.de/img/orcid-mark.12x12.pngRaghunath Tewari:
Space efficient algorithm for solving reachability using tree decomposition and separators. Theor. Comput. Sci. 982: 114251 (2024)
鐘奇恩  劉蕃熙  鄭百里  詹子慶  吳孟哲

 

Robert HickingbothamFreddie IllingworthBojan MoharDavid R. Wood:
Treewidth, Circle Graphs, and Circular Drawings. SIAM J. Discret. Math. 38(1): 965-987 (2024)
方淑玲

 

Samuel Eduardo da SilvaUéverton S. Souzahttps://dblp.uni-trier.de/img/orcid-mark.12x12.png:
Decoding Tree Decompositions from Permutations. LATIN (1) 2024: 19-34
蔡斯昊  黃振嘉  盧冠綸  余書齊

 

-----------

May 28, 2024

Abel Cabrera Martínezhttps://dblp.uni-trier.de/img/orcid-mark.12x12.png:
An improved upper bound on the domination number of a tree. Discret. Appl. Math. 343: 44-48 (2024)
PAULO ENRIQUE LINARES OTOYA

 Kennteth DadedziStephan G. Wagnerhttps://dblp.uni-trier.de/img/orcid-mark.12x12.png:
On the distribution of eigenvalues of increasing trees. Discret. Math. 347(2): 113762 (2024)
呂宗澤  鞠睿陽  李昕叡  陳品睿

Silvia ToloJohn D. Andrews:
Fault Tree Analysis Including Component Dependencies. IEEE Trans. Reliab. 73(1): 413-421 (2024)
于珩  廖子言

Jack DippelAdrian Vetta:
One n Remains to Settle the Tree Conjecture. STACS 2024: 28:1-28:16
簡謙益    蔡旻諺   王政祺  林秉軒

 

Selected papers for presentation:
(Another option is that you may choose your own topic to present. Please talk to me in advance if you wish to do so.)

1.          Shang-En HuangDawei HuangTsvi Kopelowitz, Seth Pettie, Mikkel Thorup:
Fully Dynamic Connectivity in O(log n(loglog n)2) Amortized Expected Time. TheoretiCS 2 (2023)
劉宇倫  蘇子碩  陳建宏  譚雋飛  趙容

2.          Samuel Thomashttps://dblp.uni-trier.de/img/orcid-mark.12x12.pngKidus Worknehhttps://dblp.uni-trier.de/img/orcid-mark.12x12.pngAnge-Thierry Ishimwehttps://dblp.uni-trier.de/img/orcid-mark.12x12.pngZack McKevitthttps://dblp.uni-trier.de/img/orcid-mark.12x12.pngPhaedra S. Curlinhttps://dblp.uni-trier.de/img/orcid-mark.12x12.pngR. Iris Baharhttps://dblp.uni-trier.de/img/orcid-mark.12x12.pngJoseph Izraelevitzhttps://dblp.uni-trier.de/img/orcid-mark.12x12.pngTamara Lehmanhttps://dblp.uni-trier.de/img/orcid-mark.12x12.png:
Baobab Merkle Tree for Efficient Secure Memory. IEEE Comput. Archit. Lett. 23(1): 33-36 (2024)
CASSANDRA LE PADELLEC and PAUL FEICHTENSCHLAGER

3.          Amir BarghiDaryl R. DeFord:
Ranking trees based on global centrality measures. Discret. Appl. Math. 343: 231-257 (2024)

4.          Egor Lappohttps://dblp.uni-trier.de/img/orcid-mark.12x12.pngNoah A. Rosenberghttps://dblp.uni-trier.de/img/orcid-mark.12x12.png:
A lattice structure for ancestral configurations arising from the relationship between gene trees and species trees. Discret. Appl. Math. 343: 65-81 (2024)

5.          Abel Cabrera Martínezhttps://dblp.uni-trier.de/img/orcid-mark.12x12.png:
An improved upper bound on the domination number of a tree. Discret. Appl. Math. 343: 44-48 (2024)
PAULO ENRIQUE LINARES OTOYA

6.          Kennteth DadedziStephan G. Wagnerhttps://dblp.uni-trier.de/img/orcid-mark.12x12.png:
On the distribution of eigenvalues of increasing trees. Discret. Math. 347(2): 113762 (2024)
呂宗澤  鞠睿陽  李昕叡  陳品睿

7.          Miguel LiconaJoaquín Teyhttps://dblp.uni-trier.de/img/orcid-mark.12x12.png:
Conservative trees. Discret. Math. 347(3): 113854 (2024)
周昱宏  蔡莉亞  陳怜均

8.          Thomas Mattmanhttps://dblp.uni-trier.de/img/orcid-mark.12x12.png:
A Novel Count of the Spanning Trees of a Cube. Graphs Comb. 40(1): 19 (2024)

9.          Mikolaj Bojanczykhttps://dblp.uni-trier.de/img/orcid-mark.12x12.pngBartek Klinhttps://dblp.uni-trier.de/img/orcid-mark.12x12.png:
Polyregular Functions on Unordered Trees of Bounded Height. Proc. ACM Program. Lang. 8(POPL): 1326-1351 (2024)

10.      Ruben BeckerYuval EmekMohsen GhaffariChristoph Lenzen:
Decentralized Low-Stretch Trees via Low Diameter Graph Decompositions. SIAM J. Comput. 53(2): 247-286 (2024)

11.      Robert HickingbothamFreddie IllingworthBojan MoharDavid R. Wood:
Treewidth, Circle Graphs, and Circular Drawings. SIAM J. Discret. Math. 38(1): 965-987 (2024)
方淑玲

12.      Pakawut JiradilokSupanat Kamtue:
Transportation Distance between Probability Measures on the Infinite Regular Tree. SIAM J. Discret. Math. 38(1): 1113-1157 (2024)

13.      Subhash Bhagathttps://dblp.uni-trier.de/img/orcid-mark.12x12.pngAndrzej Pelc:
Deterministic rendezvous in infinite trees. Theor. Comput. Sci. 984: 114313 (2024)
吳政宏

14.      Rahul Jainhttps://dblp.uni-trier.de/img/orcid-mark.12x12.pngRaghunath Tewari:
Space efficient algorithm for solving reachability using tree decomposition and separators. Theor. Comput. Sci. 982: 114251 (2024)
鐘奇恩  劉蕃熙  鄭百里  詹子慶  吳孟哲

15.      Nicholas Galbraithhttps://dblp.uni-trier.de/img/orcid-mark.12x12.pngSamory Kpotufe:
Classification Tree Pruning Under Covariate Shift. IEEE Trans. Inf. Theory 70(1): 456-481 (2024)

16.      Silvia ToloJohn D. Andrews:
Fault Tree Analysis Including Component Dependencies. IEEE Trans. Reliab. 73(1): 413-421 (2024)
于珩  廖子言

17.      Kathryn Grayhttps://dblp.uni-trier.de/img/orcid-mark.12x12.pngMingwei Lihttps://dblp.uni-trier.de/img/orcid-mark.12x12.pngAbu Reyan Ahmedhttps://dblp.uni-trier.de/img/orcid-mark.12x12.pngMd. Khaledur Rahmanhttps://dblp.uni-trier.de/img/orcid-mark.12x12.pngAriful Azadhttps://dblp.uni-trier.de/img/orcid-mark.12x12.pngStephen G. Kobourovhttps://dblp.uni-trier.de/img/orcid-mark.12x12.pngKaty Börnerhttps://dblp.uni-trier.de/img/orcid-mark.12x12.png:
A Scalable Method for Readable Tree Layouts. IEEE Trans. Vis. Comput. Graph. 30(2): 1564-1578 (2024)

18.      Samuel Eduardo da SilvaUéverton S. Souzahttps://dblp.uni-trier.de/img/orcid-mark.12x12.png:
Decoding Tree Decompositions from Permutations. LATIN (1) 2024: 19-34
蔡斯昊  黃振嘉  盧冠綸  余書齊

19.      Jesper JanssonWing-Kin SungSeyed Ali TabatabaeeYutong Yang:
A Faster Algorithm for Constructing the Frequency Difference Consensus Tree. STACS 2024: 43:1-43:17
MARIA CAROLINA CORNELIA WIT and PLOY

20.      Jack DippelAdrian Vetta:
One n Remains to Settle the Tree Conjecture. STACS 2024: 28:1-28:16
簡謙益    蔡旻諺   王政祺  林秉軒

 

References (not required):

1.          Spanning Trees and Optimization Problems, by Bang Ye Wu and Kun-Mao Chao (2004), Chapman & Hall/CRC Press, USA.

2.          Related journal and conference papers