---
_id: '14888'
abstract:
- lang: eng
  text: 'A face in a curve arrangement is called popular if it is bounded by the same
    curve multiple times. Motivated by the automatic generation of curved nonogram
    puzzles, we investigate possibilities to eliminate the popular faces in an arrangement
    by inserting a single additional curve. This turns out to be NP-hard; however,
    it becomes tractable when the number of popular faces is small: We present a probabilistic
    FPT-approach in the number of popular faces.'
acknowledgement: 'This work was initiated at the 16th European Research Week on Geometric
  Graphs in Strobl in 2019. A.W. is supported by the Austrian Science Fund (FWF):
  W1230. S.T. has been funded by the Vienna Science and Technology Fund (WWTF) [10.47379/ICT19035].
  A preliminary version of this work has been presented at the 38th European Workshop
  on Computational Geometry (EuroCG 2022) in Perugia [9]. A full version of this paper,
  which includes appendices but is otherwise identical, is available as a technical
  report [10].'
alternative_title:
- LNCS
article_processing_charge: No
arxiv: 1
author:
- first_name: Phoebe
  full_name: De Nooijer, Phoebe
  last_name: De Nooijer
- first_name: Soeren
  full_name: Terziadis, Soeren
  last_name: Terziadis
- first_name: Alexandra
  full_name: Weinberger, Alexandra
  last_name: Weinberger
- first_name: Zuzana
  full_name: Masárová, Zuzana
  id: 45CFE238-F248-11E8-B48F-1D18A9856A87
  last_name: Masárová
  orcid: 0000-0002-6660-1322
- first_name: Tamara
  full_name: Mchedlidze, Tamara
  last_name: Mchedlidze
- first_name: Maarten
  full_name: Löffler, Maarten
  last_name: Löffler
- first_name: Günter
  full_name: Rote, Günter
  last_name: Rote
citation:
  ama: 'De Nooijer P, Terziadis S, Weinberger A, et al. Removing popular faces in curve
    arrangements. In: <i>31st International Symposium on Graph Drawing and Network
    Visualization</i>. Vol 14466. Springer Nature; 2024:18-33. doi:<a href="https://doi.org/10.1007/978-3-031-49275-4_2">10.1007/978-3-031-49275-4_2</a>'
  apa: 'De Nooijer, P., Terziadis, S., Weinberger, A., Masárová, Z., Mchedlidze, T.,
    Löffler, M., &#38; Rote, G. (2024). Removing popular faces in curve arrangements.
    In <i>31st International Symposium on Graph Drawing and Network Visualization</i>
    (Vol. 14466, pp. 18–33). Isola delle Femmine, Palermo, Italy: Springer Nature.
    <a href="https://doi.org/10.1007/978-3-031-49275-4_2">https://doi.org/10.1007/978-3-031-49275-4_2</a>'
  chicago: De Nooijer, Phoebe, Soeren Terziadis, Alexandra Weinberger, Zuzana Masárová,
    Tamara Mchedlidze, Maarten Löffler, and Günter Rote. “Removing Popular Faces in Curve
    Arrangements.” In <i>31st International Symposium on Graph Drawing and Network
    Visualization</i>, 14466:18–33. Springer Nature, 2024. <a href="https://doi.org/10.1007/978-3-031-49275-4_2">https://doi.org/10.1007/978-3-031-49275-4_2</a>.
  ieee: P. De Nooijer <i>et al.</i>, “Removing popular faces in curve arrangements,”
    in <i>31st International Symposium on Graph Drawing and Network Visualization</i>,
    Isola delle Femmine, Palermo, Italy, 2024, vol. 14466, pp. 18–33.
  ista: 'De Nooijer P, Terziadis S, Weinberger A, Masárová Z, Mchedlidze T, Löffler
    M, Rote G. 2024. Removing popular faces in curve arrangements. 31st International
    Symposium on Graph Drawing and Network Visualization. GD: Graph Drawing and Network
    Visualization, LNCS, vol. 14466, 18–33.'
  mla: De Nooijer, Phoebe, et al. “Removing Popular Faces in Curve Arrangements.”
    <i>31st International Symposium on Graph Drawing and Network Visualization</i>,
    vol. 14466, Springer Nature, 2024, pp. 18–33, doi:<a href="https://doi.org/10.1007/978-3-031-49275-4_2">10.1007/978-3-031-49275-4_2</a>.
  short: P. De Nooijer, S. Terziadis, A. Weinberger, Z. Masárová, T. Mchedlidze, M.
    Löffler, G. Rote, in:, 31st International Symposium on Graph Drawing and Network
    Visualization, Springer Nature, 2024, pp. 18–33.
conference:
  end_date: 2023-09-22
  location: Isola delle Femmine, Palermo, Italy
  name: 'GD: Graph Drawing and Network Visualization'
  start_date: 2023-09-20
date_created: 2024-01-28T23:01:43Z
date_published: 2024-01-06T00:00:00Z
date_updated: 2025-07-21T07:28:03Z
day: '06'
department:
- _id: UlWa
- _id: HeEd
doi: 10.1007/978-3-031-49275-4_2
external_id:
  arxiv:
  - '2202.12175'
intvolume: '     14466'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://doi.org/10.48550/arXiv.2202.12175
month: '01'
oa: 1
oa_version: Preprint
page: 18-33
project:
- _id: bdb2a702-d553-11ed-ba76-f12e3e5a3bc6
  grant_number: '101087907'
  name: 'A quantum hybrid of atoms and milligram-scale pendulums: towards gravitational
    quantum mechanics'
publication: 31st International Symposium on Graph Drawing and Network Visualization
publication_identifier:
  eissn:
  - 1611-3349
  isbn:
  - '9783031492747'
  issn:
  - 0302-9743
publication_status: published
publisher: Springer Nature
quality_controlled: '1'
scopus_import: '1'
status: public
title: Removing popular faces in curve arrangements
type: conference
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 14466
year: '2024'
...
---
_id: '12833'
abstract:
- lang: eng
  text: 'The input to the token swapping problem is a graph with vertices v1, v2,
    . . . , vn, and n tokens with labels 1,2, . . . , n, one on each vertex. The goal
    is to get token i to vertex vi for all i= 1, . . . , n using a minimum number
    of swaps, where a swap exchanges the tokens on the endpoints of an edge.Token
    swapping on a tree, also known as “sorting with a transposition tree,” is not
    known to be in P nor NP-complete. We present some partial results: 1. An optimum
    swap sequence may need to perform a swap on a leaf vertex that has the correct
    token (a “happy leaf”), disproving a conjecture of Vaughan. 2. Any algorithm that
    fixes happy leaves—as all known approximation algorithms for the problem do—has
    approximation factor at least 4/3. Furthermore, the two best-known 2-approximation
    algorithms have approximation factor exactly 2. 3. A generalized problem—weighted
    coloured token swapping—is NP-complete on trees, but solvable in polynomial time
    on paths and stars. In this version, tokens and vertices have colours, and colours
    have weights. The goal is to get every token to a vertex of the same colour, and
    the cost of a swap is the sum of the weights of the two tokens involved.'
acknowledgement: "This work was begun at the University of Waterloo and was partially
  supported by the Natural Sciences and Engineering Council of Canada (NSERC).\r\n"
article_number: '9'
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: Ahmad
  full_name: Biniaz, Ahmad
  last_name: Biniaz
- first_name: Kshitij
  full_name: Jain, Kshitij
  last_name: Jain
- first_name: Anna
  full_name: Lubiw, Anna
  last_name: Lubiw
- first_name: Zuzana
  full_name: Masárová, Zuzana
  id: 45CFE238-F248-11E8-B48F-1D18A9856A87
  last_name: Masárová
  orcid: 0000-0002-6660-1322
- first_name: Tillmann
  full_name: Miltzow, Tillmann
  last_name: Miltzow
- first_name: Debajyoti
  full_name: Mondal, Debajyoti
  last_name: Mondal
- first_name: Anurag Murty
  full_name: Naredla, Anurag Murty
  last_name: Naredla
- first_name: Josef
  full_name: Tkadlec, Josef
  id: 3F24CCC8-F248-11E8-B48F-1D18A9856A87
  last_name: Tkadlec
  orcid: 0000-0002-1097-9684
- first_name: Alexi
  full_name: Turcotte, Alexi
  last_name: Turcotte
citation:
  ama: Biniaz A, Jain K, Lubiw A, et al. Token swapping on trees. <i>Discrete Mathematics
    and Theoretical Computer Science</i>. 2023;24(2). doi:<a href="https://doi.org/10.46298/DMTCS.8383">10.46298/DMTCS.8383</a>
  apa: Biniaz, A., Jain, K., Lubiw, A., Masárová, Z., Miltzow, T., Mondal, D., … Turcotte,
    A. (2023). Token swapping on trees. <i>Discrete Mathematics and Theoretical Computer
    Science</i>. EPI Sciences. <a href="https://doi.org/10.46298/DMTCS.8383">https://doi.org/10.46298/DMTCS.8383</a>
  chicago: Biniaz, Ahmad, Kshitij Jain, Anna Lubiw, Zuzana Masárová, Tillmann Miltzow,
    Debajyoti Mondal, Anurag Murty Naredla, Josef Tkadlec, and Alexi Turcotte. “Token
    Swapping on Trees.” <i>Discrete Mathematics and Theoretical Computer Science</i>.
    EPI Sciences, 2023. <a href="https://doi.org/10.46298/DMTCS.8383">https://doi.org/10.46298/DMTCS.8383</a>.
  ieee: A. Biniaz <i>et al.</i>, “Token swapping on trees,” <i>Discrete Mathematics
    and Theoretical Computer Science</i>, vol. 24, no. 2. EPI Sciences, 2023.
  ista: Biniaz A, Jain K, Lubiw A, Masárová Z, Miltzow T, Mondal D, Naredla AM, Tkadlec
    J, Turcotte A. 2023. Token swapping on trees. Discrete Mathematics and Theoretical
    Computer Science. 24(2), 9.
  mla: Biniaz, Ahmad, et al. “Token Swapping on Trees.” <i>Discrete Mathematics and
    Theoretical Computer Science</i>, vol. 24, no. 2, 9, EPI Sciences, 2023, doi:<a
    href="https://doi.org/10.46298/DMTCS.8383">10.46298/DMTCS.8383</a>.
  short: A. Biniaz, K. Jain, A. Lubiw, Z. Masárová, T. Miltzow, D. Mondal, A.M. Naredla,
    J. Tkadlec, A. Turcotte, Discrete Mathematics and Theoretical Computer Science
    24 (2023).
date_created: 2023-04-16T22:01:08Z
date_published: 2023-01-18T00:00:00Z
date_updated: 2024-01-04T12:42:09Z
day: '18'
ddc:
- '000'
department:
- _id: KrCh
- _id: HeEd
- _id: UlWa
doi: 10.46298/DMTCS.8383
external_id:
  arxiv:
  - '1903.06981'
file:
- access_level: open_access
  checksum: 439102ea4f6e2aeefd7107dfb9ccf532
  content_type: application/pdf
  creator: dernst
  date_created: 2023-04-17T08:10:28Z
  date_updated: 2023-04-17T08:10:28Z
  file_id: '12844'
  file_name: 2022_DMTCS_Biniaz.pdf
  file_size: 2072197
  relation: main_file
  success: 1
file_date_updated: 2023-04-17T08:10:28Z
has_accepted_license: '1'
intvolume: '        24'
issue: '2'
language:
- iso: eng
month: '01'
oa: 1
oa_version: Published Version
publication: Discrete Mathematics and Theoretical Computer Science
publication_identifier:
  eissn:
  - 1365-8050
  issn:
  - 1462-7264
publication_status: published
publisher: EPI Sciences
quality_controlled: '1'
related_material:
  record:
  - id: '7950'
    relation: earlier_version
    status: public
scopus_import: '1'
status: public
title: Token swapping on trees
tmp:
  image: /images/cc_by.png
  legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
  name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
  short: CC BY (4.0)
type: journal_article
user_id: 3E5EF7F0-F248-11E8-B48F-1D18A9856A87
volume: 24
year: '2023'
...
---
_id: '11938'
abstract:
- lang: eng
  text: A matching is compatible to two or more labeled point sets of size n with
    labels {1, . . . , n} if its straight-line drawing on each of these point sets
    is crossing-free. We study the maximum number of edges in a matching compatible
    to two or more labeled point sets in general position in the plane. We show that
    for any two labeled sets of n points in convex position there exists a compatible
    matching with ⌊√2n + 1 − 1⌋ edges. More generally, for any ℓ labeled point sets
    we construct compatible matchings of size Ω(n1/ℓ). As a corresponding upper bound,
    we use probabilistic arguments to show that for any ℓ given sets of n points there
    exists a labeling of each set such that the largest compatible matching has O(n2/(ℓ+1))
    edges. Finally, we show that Θ(log n) copies of any set of n points are necessary
    and sufficient for the existence of labelings of these point sets such that any
    compatible matching consists only of a single edge.
acknowledgement: 'A.A. funded by the Marie Sklodowska-Curie grant agreement No 754411.
  Z.M. partially funded by Wittgenstein Prize, Austrian Science Fund (FWF), grant
  no. Z 342-N31. I.P., D.P., and B.V. partially supported by FWF within the collaborative
  DACH project Arrangements and Drawings as FWF project I 3340-N35. A.P. supported
  by a Schrödinger fellowship of the FWF: J-3847-N35. J.T. partially supported by
  ERC Start grant no. (279307: Graph Games), FWF grant no. P23499-N23 and S11407-N23
  (RiSE).'
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: Oswin
  full_name: Aichholzer, Oswin
  last_name: Aichholzer
- first_name: Alan M
  full_name: Arroyo Guevara, Alan M
  id: 3207FDC6-F248-11E8-B48F-1D18A9856A87
  last_name: Arroyo Guevara
  orcid: 0000-0003-2401-8670
- first_name: Zuzana
  full_name: Masárová, Zuzana
  id: 45CFE238-F248-11E8-B48F-1D18A9856A87
  last_name: Masárová
  orcid: 0000-0002-6660-1322
- first_name: Irene
  full_name: Parada, Irene
  last_name: Parada
- first_name: Daniel
  full_name: Perz, Daniel
  last_name: Perz
- first_name: Alexander
  full_name: Pilz, Alexander
  last_name: Pilz
- first_name: Josef
  full_name: Tkadlec, Josef
  id: 3F24CCC8-F248-11E8-B48F-1D18A9856A87
  last_name: Tkadlec
  orcid: 0000-0002-1097-9684
- first_name: Birgit
  full_name: Vogtenhuber, Birgit
  last_name: Vogtenhuber
citation:
  ama: Aichholzer O, Arroyo Guevara AM, Masárová Z, et al. On compatible matchings.
    <i>Journal of Graph Algorithms and Applications</i>. 2022;26(2):225-240. doi:<a
    href="https://doi.org/10.7155/jgaa.00591">10.7155/jgaa.00591</a>
  apa: Aichholzer, O., Arroyo Guevara, A. M., Masárová, Z., Parada, I., Perz, D.,
    Pilz, A., … Vogtenhuber, B. (2022). On compatible matchings. <i>Journal of Graph
    Algorithms and Applications</i>. Brown University. <a href="https://doi.org/10.7155/jgaa.00591">https://doi.org/10.7155/jgaa.00591</a>
  chicago: Aichholzer, Oswin, Alan M Arroyo Guevara, Zuzana Masárová, Irene Parada,
    Daniel Perz, Alexander Pilz, Josef Tkadlec, and Birgit Vogtenhuber. “On Compatible
    Matchings.” <i>Journal of Graph Algorithms and Applications</i>. Brown University,
    2022. <a href="https://doi.org/10.7155/jgaa.00591">https://doi.org/10.7155/jgaa.00591</a>.
  ieee: O. Aichholzer <i>et al.</i>, “On compatible matchings,” <i>Journal of Graph
    Algorithms and Applications</i>, vol. 26, no. 2. Brown University, pp. 225–240,
    2022.
  ista: Aichholzer O, Arroyo Guevara AM, Masárová Z, Parada I, Perz D, Pilz A, Tkadlec
    J, Vogtenhuber B. 2022. On compatible matchings. Journal of Graph Algorithms and
    Applications. 26(2), 225–240.
  mla: Aichholzer, Oswin, et al. “On Compatible Matchings.” <i>Journal of Graph Algorithms
    and Applications</i>, vol. 26, no. 2, Brown University, 2022, pp. 225–40, doi:<a
    href="https://doi.org/10.7155/jgaa.00591">10.7155/jgaa.00591</a>.
  short: O. Aichholzer, A.M. Arroyo Guevara, Z. Masárová, I. Parada, D. Perz, A. Pilz,
    J. Tkadlec, B. Vogtenhuber, Journal of Graph Algorithms and Applications 26 (2022)
    225–240.
date_created: 2022-08-21T22:01:56Z
date_published: 2022-06-01T00:00:00Z
date_updated: 2023-02-23T13:54:21Z
day: '01'
ddc:
- '000'
department:
- _id: UlWa
- _id: HeEd
- _id: KrCh
doi: 10.7155/jgaa.00591
ec_funded: 1
external_id:
  arxiv:
  - '2101.03928'
file:
- access_level: open_access
  checksum: dc6e255e3558faff924fd9e370886c11
  content_type: application/pdf
  creator: dernst
  date_created: 2022-08-22T06:42:42Z
  date_updated: 2022-08-22T06:42:42Z
  file_id: '11940'
  file_name: 2022_JourGraphAlgorithmsApplic_Aichholzer.pdf
  file_size: 694538
  relation: main_file
  success: 1
file_date_updated: 2022-08-22T06:42:42Z
has_accepted_license: '1'
intvolume: '        26'
issue: '2'
language:
- iso: eng
month: '06'
oa: 1
oa_version: Published Version
page: 225-240
project:
- _id: 260C2330-B435-11E9-9278-68D0E5697425
  call_identifier: H2020
  grant_number: '754411'
  name: ISTplus - Postdoctoral Fellowships
- _id: 268116B8-B435-11E9-9278-68D0E5697425
  call_identifier: FWF
  grant_number: Z00342
  name: The Wittgenstein Prize
- _id: 2581B60A-B435-11E9-9278-68D0E5697425
  call_identifier: FP7
  grant_number: '279307'
  name: 'Quantitative Graph Games: Theory and Applications'
- _id: 2584A770-B435-11E9-9278-68D0E5697425
  call_identifier: FWF
  grant_number: P 23499-N23
  name: Modern Graph Algorithmic Techniques in Formal Verification
- _id: 25863FF4-B435-11E9-9278-68D0E5697425
  call_identifier: FWF
  grant_number: S11407
  name: Game Theory
publication: Journal of Graph Algorithms and Applications
publication_identifier:
  issn:
  - 1526-1719
publication_status: published
publisher: Brown University
quality_controlled: '1'
related_material:
  record:
  - id: '9296'
    relation: earlier_version
    status: public
scopus_import: '1'
status: public
title: On compatible matchings
tmp:
  image: /images/cc_by.png
  legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
  name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
  short: CC BY (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 26
year: '2022'
...
---
_id: '8317'
abstract:
- lang: eng
  text: When can a polyomino piece of paper be folded into a unit cube? Prior work
    studied tree-like polyominoes, but polyominoes with holes remain an intriguing
    open problem. We present sufficient conditions for a polyomino with one or several
    holes to fold into a cube, and conditions under which cube folding is impossible.
    In particular, we show that all but five special “basic” holes guarantee foldability.
acknowledgement: This research was performed in part at the 33rd Bellairs Winter Workshop
  on Computational Geometry. We thank all other participants for a fruitful atmosphere.
  H. Akitaya was supported by NSF CCF-1422311 & 1423615. Z. Masárová was partially
  funded by Wittgenstein Prize, Austrian Science Fund (FWF), grant no. Z 342-N31.
article_number: '101700'
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: Oswin
  full_name: Aichholzer, Oswin
  last_name: Aichholzer
- first_name: Hugo A.
  full_name: Akitaya, Hugo A.
  last_name: Akitaya
- first_name: Kenneth C.
  full_name: Cheung, Kenneth C.
  last_name: Cheung
- first_name: Erik D.
  full_name: Demaine, Erik D.
  last_name: Demaine
- first_name: Martin L.
  full_name: Demaine, Martin L.
  last_name: Demaine
- first_name: Sándor P.
  full_name: Fekete, Sándor P.
  last_name: Fekete
- first_name: Linda
  full_name: Kleist, Linda
  last_name: Kleist
- first_name: Irina
  full_name: Kostitsyna, Irina
  last_name: Kostitsyna
- first_name: Maarten
  full_name: Löffler, Maarten
  last_name: Löffler
- first_name: Zuzana
  full_name: Masárová, Zuzana
  id: 45CFE238-F248-11E8-B48F-1D18A9856A87
  last_name: Masárová
  orcid: 0000-0002-6660-1322
- first_name: Klara
  full_name: Mundilova, Klara
  last_name: Mundilova
- first_name: Christiane
  full_name: Schmidt, Christiane
  last_name: Schmidt
citation:
  ama: 'Aichholzer O, Akitaya HA, Cheung KC, et al. Folding polyominoes with holes
    into a cube. <i>Computational Geometry: Theory and Applications</i>. 2021;93.
    doi:<a href="https://doi.org/10.1016/j.comgeo.2020.101700">10.1016/j.comgeo.2020.101700</a>'
  apa: 'Aichholzer, O., Akitaya, H. A., Cheung, K. C., Demaine, E. D., Demaine, M.
    L., Fekete, S. P., … Schmidt, C. (2021). Folding polyominoes with holes into a
    cube. <i>Computational Geometry: Theory and Applications</i>. Elsevier. <a href="https://doi.org/10.1016/j.comgeo.2020.101700">https://doi.org/10.1016/j.comgeo.2020.101700</a>'
  chicago: 'Aichholzer, Oswin, Hugo A. Akitaya, Kenneth C. Cheung, Erik D. Demaine,
    Martin L. Demaine, Sándor P. Fekete, Linda Kleist, et al. “Folding Polyominoes
    with Holes into a Cube.” <i>Computational Geometry: Theory and Applications</i>.
    Elsevier, 2021. <a href="https://doi.org/10.1016/j.comgeo.2020.101700">https://doi.org/10.1016/j.comgeo.2020.101700</a>.'
  ieee: 'O. Aichholzer <i>et al.</i>, “Folding polyominoes with holes into a cube,”
    <i>Computational Geometry: Theory and Applications</i>, vol. 93. Elsevier, 2021.'
  ista: 'Aichholzer O, Akitaya HA, Cheung KC, Demaine ED, Demaine ML, Fekete SP, Kleist
    L, Kostitsyna I, Löffler M, Masárová Z, Mundilova K, Schmidt C. 2021. Folding
    polyominoes with holes into a cube. Computational Geometry: Theory and Applications.
    93, 101700.'
  mla: 'Aichholzer, Oswin, et al. “Folding Polyominoes with Holes into a Cube.” <i>Computational
    Geometry: Theory and Applications</i>, vol. 93, 101700, Elsevier, 2021, doi:<a
    href="https://doi.org/10.1016/j.comgeo.2020.101700">10.1016/j.comgeo.2020.101700</a>.'
  short: 'O. Aichholzer, H.A. Akitaya, K.C. Cheung, E.D. Demaine, M.L. Demaine, S.P.
    Fekete, L. Kleist, I. Kostitsyna, M. Löffler, Z. Masárová, K. Mundilova, C. Schmidt,
    Computational Geometry: Theory and Applications 93 (2021).'
date_created: 2020-08-30T22:01:09Z
date_published: 2021-02-01T00:00:00Z
date_updated: 2023-08-04T10:57:42Z
day: '01'
department:
- _id: HeEd
doi: 10.1016/j.comgeo.2020.101700
external_id:
  arxiv:
  - '1910.09917'
  isi:
  - '000579185100004'
intvolume: '        93'
isi: 1
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://arxiv.org/abs/1910.09917v3
month: '02'
oa: 1
oa_version: Preprint
project:
- _id: 268116B8-B435-11E9-9278-68D0E5697425
  call_identifier: FWF
  grant_number: Z00342
  name: The Wittgenstein Prize
publication: 'Computational Geometry: Theory and Applications'
publication_identifier:
  issn:
  - '09257721'
publication_status: published
publisher: Elsevier
quality_controlled: '1'
related_material:
  record:
  - id: '6989'
    relation: shorter_version
    status: public
scopus_import: '1'
status: public
title: Folding polyominoes with holes into a cube
type: journal_article
user_id: 4359f0d1-fa6c-11eb-b949-802e58b17ae8
volume: 93
year: '2021'
...
---
_id: '9296'
abstract:
- lang: eng
  text: ' matching is compatible to two or more labeled point sets of size n with
    labels   {1,…,n}  if its straight-line drawing on each of these point sets is
    crossing-free. We study the maximum number of edges in a matching compatible to
    two or more labeled point sets in general position in the plane. We show that
    for any two labeled convex sets of n points there exists a compatible matching
    with   ⌊2n−−√⌋  edges. More generally, for any   ℓ  labeled point sets we construct
    compatible matchings of size   Ω(n1/ℓ) . As a corresponding upper bound, we use
    probabilistic arguments to show that for any   ℓ  given sets of n points there
    exists a labeling of each set such that the largest compatible matching has   O(n2/(ℓ+1))  edges.
    Finally, we show that   Θ(logn)  copies of any set of n points are necessary and
    sufficient for the existence of a labeling such that any compatible matching consists
    only of a single edge.'
acknowledgement: 'A.A. funded by the Marie Skłodowska-Curie grant agreement No. 754411.
  Z.M. partially funded by Wittgenstein Prize, Austrian Science Fund (FWF), grant
  no. Z 342-N31. I.P., D.P., and B.V. partially supported by FWF within the collaborative
  DACH project Arrangements and Drawings as FWF project I 3340-N35. A.P. supported
  by a Schrödinger fellowship of the FWF: J-3847-N35. J.T. partially supported by
  ERC Start grant no. (279307: Graph Games), FWF grant no. P23499-N23 and S11407-N23
  (RiSE).'
alternative_title:
- LNCS
article_processing_charge: No
arxiv: 1
author:
- first_name: Oswin
  full_name: Aichholzer, Oswin
  last_name: Aichholzer
- first_name: Alan M
  full_name: Arroyo Guevara, Alan M
  id: 3207FDC6-F248-11E8-B48F-1D18A9856A87
  last_name: Arroyo Guevara
  orcid: 0000-0003-2401-8670
- first_name: Zuzana
  full_name: Masárová, Zuzana
  id: 45CFE238-F248-11E8-B48F-1D18A9856A87
  last_name: Masárová
  orcid: 0000-0002-6660-1322
- first_name: Irene
  full_name: Parada, Irene
  last_name: Parada
- first_name: Daniel
  full_name: Perz, Daniel
  last_name: Perz
- first_name: Alexander
  full_name: Pilz, Alexander
  last_name: Pilz
- first_name: Josef
  full_name: Tkadlec, Josef
  id: 3F24CCC8-F248-11E8-B48F-1D18A9856A87
  last_name: Tkadlec
  orcid: 0000-0002-1097-9684
- first_name: Birgit
  full_name: Vogtenhuber, Birgit
  last_name: Vogtenhuber
citation:
  ama: 'Aichholzer O, Arroyo Guevara AM, Masárová Z, et al. On compatible matchings.
    In: <i>15th International Conference on Algorithms and Computation</i>. Vol 12635.
    Springer Nature; 2021:221-233. doi:<a href="https://doi.org/10.1007/978-3-030-68211-8_18">10.1007/978-3-030-68211-8_18</a>'
  apa: 'Aichholzer, O., Arroyo Guevara, A. M., Masárová, Z., Parada, I., Perz, D.,
    Pilz, A., … Vogtenhuber, B. (2021). On compatible matchings. In <i>15th International
    Conference on Algorithms and Computation</i> (Vol. 12635, pp. 221–233). Yangon,
    Myanmar: Springer Nature. <a href="https://doi.org/10.1007/978-3-030-68211-8_18">https://doi.org/10.1007/978-3-030-68211-8_18</a>'
  chicago: Aichholzer, Oswin, Alan M Arroyo Guevara, Zuzana Masárová, Irene Parada,
    Daniel Perz, Alexander Pilz, Josef Tkadlec, and Birgit Vogtenhuber. “On Compatible
    Matchings.” In <i>15th International Conference on Algorithms and Computation</i>,
    12635:221–33. Springer Nature, 2021. <a href="https://doi.org/10.1007/978-3-030-68211-8_18">https://doi.org/10.1007/978-3-030-68211-8_18</a>.
  ieee: O. Aichholzer <i>et al.</i>, “On compatible matchings,” in <i>15th International
    Conference on Algorithms and Computation</i>, Yangon, Myanmar, 2021, vol. 12635,
    pp. 221–233.
  ista: 'Aichholzer O, Arroyo Guevara AM, Masárová Z, Parada I, Perz D, Pilz A, Tkadlec
    J, Vogtenhuber B. 2021. On compatible matchings. 15th International Conference
    on Algorithms and Computation. WALCOM: Algorithms and Computation, LNCS, vol.
    12635, 221–233.'
  mla: Aichholzer, Oswin, et al. “On Compatible Matchings.” <i>15th International
    Conference on Algorithms and Computation</i>, vol. 12635, Springer Nature, 2021,
    pp. 221–33, doi:<a href="https://doi.org/10.1007/978-3-030-68211-8_18">10.1007/978-3-030-68211-8_18</a>.
  short: O. Aichholzer, A.M. Arroyo Guevara, Z. Masárová, I. Parada, D. Perz, A. Pilz,
    J. Tkadlec, B. Vogtenhuber, in:, 15th International Conference on Algorithms and
    Computation, Springer Nature, 2021, pp. 221–233.
conference:
  end_date: 2021-03-02
  location: Yangon, Myanmar
  name: 'WALCOM: Algorithms and Computation'
  start_date: 2021-02-28
date_created: 2021-03-28T22:01:41Z
date_published: 2021-02-16T00:00:00Z
date_updated: 2023-02-21T16:33:44Z
day: '16'
department:
- _id: UlWa
- _id: HeEd
- _id: KrCh
doi: 10.1007/978-3-030-68211-8_18
ec_funded: 1
external_id:
  arxiv:
  - '2101.03928'
intvolume: '     12635'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://arxiv.org/abs/2101.03928
month: '02'
oa: 1
oa_version: Preprint
page: 221-233
project:
- _id: 260C2330-B435-11E9-9278-68D0E5697425
  call_identifier: H2020
  grant_number: '754411'
  name: ISTplus - Postdoctoral Fellowships
- _id: 268116B8-B435-11E9-9278-68D0E5697425
  call_identifier: FWF
  grant_number: Z00342
  name: The Wittgenstein Prize
- _id: 2581B60A-B435-11E9-9278-68D0E5697425
  call_identifier: FP7
  grant_number: '279307'
  name: 'Quantitative Graph Games: Theory and Applications'
- _id: 2584A770-B435-11E9-9278-68D0E5697425
  call_identifier: FWF
  grant_number: P 23499-N23
  name: Modern Graph Algorithmic Techniques in Formal Verification
- _id: 25863FF4-B435-11E9-9278-68D0E5697425
  call_identifier: FWF
  grant_number: S11407
  name: Game Theory
publication: 15th International Conference on Algorithms and Computation
publication_identifier:
  eissn:
  - '16113349'
  isbn:
  - '9783030682101'
  issn:
  - '03029743'
publication_status: published
publisher: Springer Nature
quality_controlled: '1'
related_material:
  record:
  - id: '11938'
    relation: later_version
    status: public
scopus_import: '1'
status: public
title: On compatible matchings
type: conference
user_id: D865714E-FA4E-11E9-B85B-F5C5E5697425
volume: 12635
year: '2021'
...
---
_id: '7944'
abstract:
- lang: eng
  text: "This thesis considers two examples of reconfiguration problems: flipping
    edges in edge-labelled triangulations of planar point sets and swapping labelled
    tokens placed on vertices of a graph. In both cases the studied structures – all
    the triangulations of a given point set or all token placements on a given graph
    – can be thought of as vertices of the so-called reconfiguration graph, in which
    two vertices are adjacent if the corresponding structures differ by a single elementary
    operation – by a flip of a diagonal in a triangulation or by a swap of tokens
    on adjacent vertices, respectively. We study the reconfiguration of one instance
    of a structure into another via (shortest) paths in the reconfiguration graph.\r\n\r\nFor
    triangulations of point sets in which each edge has a unique label and a flip
    transfers the label from the removed edge to the new edge, we prove a polynomial-time
    testable condition, called the Orbit Theorem, that characterizes when two triangulations
    of the same point set lie in the same connected component of the reconfiguration
    graph. The condition was first conjectured by Bose, Lubiw, Pathak and Verdonschot.
    We additionally provide a polynomial time algorithm that computes a reconfiguring
    flip sequence, if it exists. Our proof of the Orbit Theorem uses topological properties
    of a certain high-dimensional cell complex that has the usual reconfiguration
    graph as its 1-skeleton.\r\n\r\nIn the context of token swapping on a tree graph,
    we make partial progress on the problem of finding shortest reconfiguration sequences.
    We disprove the so-called Happy Leaf Conjecture and demonstrate the importance
    of swapping tokens that are already placed at the correct vertices. We also prove
    that a generalization of the problem to weighted coloured token swapping is NP-hard
    on trees but solvable in polynomial time on paths and stars."
alternative_title:
- ISTA Thesis
article_processing_charge: No
author:
- first_name: Zuzana
  full_name: Masárová, Zuzana
  id: 45CFE238-F248-11E8-B48F-1D18A9856A87
  last_name: Masárová
  orcid: 0000-0002-6660-1322
citation:
  ama: Masárová Z. Reconfiguration problems. 2020. doi:<a href="https://doi.org/10.15479/AT:ISTA:7944">10.15479/AT:ISTA:7944</a>
  apa: Masárová, Z. (2020). <i>Reconfiguration problems</i>. Institute of Science
    and Technology Austria. <a href="https://doi.org/10.15479/AT:ISTA:7944">https://doi.org/10.15479/AT:ISTA:7944</a>
  chicago: Masárová, Zuzana. “Reconfiguration Problems.” Institute of Science and
    Technology Austria, 2020. <a href="https://doi.org/10.15479/AT:ISTA:7944">https://doi.org/10.15479/AT:ISTA:7944</a>.
  ieee: Z. Masárová, “Reconfiguration problems,” Institute of Science and Technology
    Austria, 2020.
  ista: Masárová Z. 2020. Reconfiguration problems. Institute of Science and Technology
    Austria.
  mla: Masárová, Zuzana. <i>Reconfiguration Problems</i>. Institute of Science and
    Technology Austria, 2020, doi:<a href="https://doi.org/10.15479/AT:ISTA:7944">10.15479/AT:ISTA:7944</a>.
  short: Z. Masárová, Reconfiguration Problems, Institute of Science and Technology
    Austria, 2020.
date_created: 2020-06-08T00:49:46Z
date_published: 2020-06-09T00:00:00Z
date_updated: 2023-09-07T13:17:37Z
day: '09'
ddc:
- '516'
- '514'
degree_awarded: PhD
department:
- _id: HeEd
- _id: UlWa
doi: 10.15479/AT:ISTA:7944
file:
- access_level: open_access
  checksum: df688bc5a82b50baee0b99d25fc7b7f0
  content_type: application/pdf
  creator: zmasarov
  date_created: 2020-06-08T00:34:00Z
  date_updated: 2020-07-14T12:48:05Z
  file_id: '7945'
  file_name: THESIS_Zuzka_Masarova.pdf
  file_size: 13661779
  relation: main_file
- access_level: closed
  checksum: 45341a35b8f5529c74010b7af43ac188
  content_type: application/zip
  creator: zmasarov
  date_created: 2020-06-08T00:35:30Z
  date_updated: 2020-07-14T12:48:05Z
  file_id: '7946'
  file_name: THESIS_Zuzka_Masarova_SOURCE_FILES.zip
  file_size: 32184006
  relation: source_file
file_date_updated: 2020-07-14T12:48:05Z
has_accepted_license: '1'
keyword:
- reconfiguration
- reconfiguration graph
- triangulations
- flip
- constrained triangulations
- shellability
- piecewise-linear balls
- token swapping
- trees
- coloured weighted token swapping
language:
- iso: eng
license: https://creativecommons.org/licenses/by-sa/4.0/
month: '06'
oa: 1
oa_version: Published Version
page: '160'
publication_identifier:
  isbn:
  - 978-3-99078-005-3
  issn:
  - 2663-337X
publication_status: published
publisher: Institute of Science and Technology Austria
related_material:
  record:
  - id: '7950'
    relation: part_of_dissertation
    status: public
  - id: '5986'
    relation: part_of_dissertation
    status: public
status: public
supervisor:
- first_name: Uli
  full_name: Wagner, Uli
  id: 36690CA2-F248-11E8-B48F-1D18A9856A87
  last_name: Wagner
  orcid: 0000-0002-1494-0568
- first_name: Herbert
  full_name: Edelsbrunner, Herbert
  id: 3FB178DA-F248-11E8-B48F-1D18A9856A87
  last_name: Edelsbrunner
  orcid: 0000-0002-9823-6833
title: Reconfiguration problems
tmp:
  image: /images/cc_by_sa.png
  legal_code_url: https://creativecommons.org/licenses/by-sa/4.0/legalcode
  name: Creative Commons Attribution-ShareAlike 4.0 International Public License (CC
    BY-SA 4.0)
  short: CC BY-SA (4.0)
type: dissertation
user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1
year: '2020'
...
---
_id: '7950'
abstract:
- lang: eng
  text: "The input to the token swapping problem is a graph with vertices v1, v2,
    . . . , vn, and n tokens with labels 1,2, . . . , n, one on each vertex.  The
    goal is to get token i to vertex vi for all i= 1, . . . , n using a minimum number
    of swaps, where a swap exchanges the tokens on the endpoints of an edge.Token
    swapping on a tree, also known as “sorting with a transposition tree,” is not
    known to be in P nor NP-complete.  We present some partial results:\r\n1.  An
    optimum swap sequence may need to perform a swap on a leaf vertex that has the
    correct token (a “happy leaf”), disproving a conjecture of Vaughan.\r\n2.  Any
    algorithm that fixes happy leaves—as all known approximation algorithms for the
    problem do—has approximation factor at least 4/3.  Furthermore, the two best-known
    2-approximation algorithms have approximation factor exactly 2.\r\n3.  A generalized
    problem—weighted coloured token swapping—is NP-complete on trees, but solvable
    in polynomial time on paths and stars.  In this version, tokens and  vertices
    \ have  colours,  and  colours  have  weights.   The  goal  is  to  get  every
    token to a vertex of the same colour, and the cost of a swap is the sum of the
    weights of the two tokens involved."
article_number: '1903.06981'
article_processing_charge: No
arxiv: 1
author:
- first_name: Ahmad
  full_name: Biniaz, Ahmad
  last_name: Biniaz
- first_name: Kshitij
  full_name: Jain, Kshitij
  last_name: Jain
- first_name: Anna
  full_name: Lubiw, Anna
  last_name: Lubiw
- first_name: Zuzana
  full_name: Masárová, Zuzana
  id: 45CFE238-F248-11E8-B48F-1D18A9856A87
  last_name: Masárová
  orcid: 0000-0002-6660-1322
- first_name: Tillmann
  full_name: Miltzow, Tillmann
  last_name: Miltzow
- first_name: Debajyoti
  full_name: Mondal, Debajyoti
  last_name: Mondal
- first_name: Anurag Murty
  full_name: Naredla, Anurag Murty
  last_name: Naredla
- first_name: Josef
  full_name: Tkadlec, Josef
  id: 3F24CCC8-F248-11E8-B48F-1D18A9856A87
  last_name: Tkadlec
  orcid: 0000-0002-1097-9684
- first_name: Alexi
  full_name: Turcotte, Alexi
  last_name: Turcotte
citation:
  ama: Biniaz A, Jain K, Lubiw A, et al. Token swapping on trees. <i>arXiv</i>.
  apa: Biniaz, A., Jain, K., Lubiw, A., Masárová, Z., Miltzow, T., Mondal, D., … Turcotte,
    A. (n.d.). Token swapping on trees. <i>arXiv</i>.
  chicago: Biniaz, Ahmad, Kshitij Jain, Anna Lubiw, Zuzana Masárová, Tillmann Miltzow,
    Debajyoti Mondal, Anurag Murty Naredla, Josef Tkadlec, and Alexi Turcotte. “Token
    Swapping on Trees.” <i>ArXiv</i>, n.d.
  ieee: A. Biniaz <i>et al.</i>, “Token swapping on trees,” <i>arXiv</i>. .
  ista: Biniaz A, Jain K, Lubiw A, Masárová Z, Miltzow T, Mondal D, Naredla AM, Tkadlec
    J, Turcotte A. Token swapping on trees. arXiv, 1903.06981.
  mla: Biniaz, Ahmad, et al. “Token Swapping on Trees.” <i>ArXiv</i>, 1903.06981.
  short: A. Biniaz, K. Jain, A. Lubiw, Z. Masárová, T. Miltzow, D. Mondal, A.M. Naredla,
    J. Tkadlec, A. Turcotte, ArXiv (n.d.).
date_created: 2020-06-08T12:25:25Z
date_published: 2019-03-16T00:00:00Z
date_updated: 2024-01-04T12:42:08Z
day: '16'
department:
- _id: HeEd
- _id: UlWa
- _id: KrCh
external_id:
  arxiv:
  - '1903.06981'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://arxiv.org/abs/1903.06981
month: '03'
oa: 1
oa_version: Preprint
publication: arXiv
publication_status: submitted
related_material:
  record:
  - id: '7944'
    relation: dissertation_contains
    status: public
  - id: '12833'
    relation: later_version
    status: public
status: public
title: Token swapping on trees
type: preprint
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
year: '2019'
...
---
_id: '6989'
abstract:
- lang: eng
  text: 'When can a polyomino piece of paper be folded into a unit cube? Prior work
    studied tree-like polyominoes, but polyominoes with holes remain an intriguing
    open problem. We present sufficient conditions for a polyomino with hole(s) to
    fold into a cube, and conditions under which cube folding is impossible. In particular,
    we show that all but five special simple holes guarantee foldability. '
acknowledgement: This research was performed in part at the 33rd BellairsWinter  Workshop  on  Computational  Geometry.    Wethank
  all other participants for a fruitful atmosphere.
article_processing_charge: No
arxiv: 1
author:
- first_name: Oswin
  full_name: Aichholzer, Oswin
  last_name: Aichholzer
- first_name: Hugo A
  full_name: Akitaya, Hugo A
  last_name: Akitaya
- first_name: Kenneth C
  full_name: Cheung, Kenneth C
  last_name: Cheung
- first_name: Erik D
  full_name: Demaine, Erik D
  last_name: Demaine
- first_name: Martin L
  full_name: Demaine, Martin L
  last_name: Demaine
- first_name: Sandor P
  full_name: Fekete, Sandor P
  last_name: Fekete
- first_name: Linda
  full_name: Kleist, Linda
  last_name: Kleist
- first_name: Irina
  full_name: Kostitsyna, Irina
  last_name: Kostitsyna
- first_name: Maarten
  full_name: Löffler, Maarten
  last_name: Löffler
- first_name: Zuzana
  full_name: Masárová, Zuzana
  id: 45CFE238-F248-11E8-B48F-1D18A9856A87
  last_name: Masárová
  orcid: 0000-0002-6660-1322
- first_name: Klara
  full_name: Mundilova, Klara
  last_name: Mundilova
- first_name: Christiane
  full_name: Schmidt, Christiane
  last_name: Schmidt
citation:
  ama: 'Aichholzer O, Akitaya HA, Cheung KC, et al. Folding polyominoes with holes
    into a cube. In: <i>Proceedings of the 31st Canadian Conference on Computational
    Geometry</i>. Canadian Conference on Computational Geometry; 2019:164-170.'
  apa: 'Aichholzer, O., Akitaya, H. A., Cheung, K. C., Demaine, E. D., Demaine, M.
    L., Fekete, S. P., … Schmidt, C. (2019). Folding polyominoes with holes into a
    cube. In <i>Proceedings of the 31st Canadian Conference on Computational Geometry</i>
    (pp. 164–170). Edmonton, Canada: Canadian Conference on Computational Geometry.'
  chicago: Aichholzer, Oswin, Hugo A Akitaya, Kenneth C Cheung, Erik D Demaine, Martin
    L Demaine, Sandor P Fekete, Linda Kleist, et al. “Folding Polyominoes with Holes
    into a Cube.” In <i>Proceedings of the 31st Canadian Conference on Computational
    Geometry</i>, 164–70. Canadian Conference on Computational Geometry, 2019.
  ieee: O. Aichholzer <i>et al.</i>, “Folding polyominoes with holes into a cube,”
    in <i>Proceedings of the 31st Canadian Conference on Computational Geometry</i>,
    Edmonton, Canada, 2019, pp. 164–170.
  ista: 'Aichholzer O, Akitaya HA, Cheung KC, Demaine ED, Demaine ML, Fekete SP, Kleist
    L, Kostitsyna I, Löffler M, Masárová Z, Mundilova K, Schmidt C. 2019. Folding
    polyominoes with holes into a cube. Proceedings of the 31st Canadian Conference
    on Computational Geometry. CCCG: Canadian Conference in Computational Geometry,
    164–170.'
  mla: Aichholzer, Oswin, et al. “Folding Polyominoes with Holes into a Cube.” <i>Proceedings
    of the 31st Canadian Conference on Computational Geometry</i>, Canadian Conference
    on Computational Geometry, 2019, pp. 164–70.
  short: O. Aichholzer, H.A. Akitaya, K.C. Cheung, E.D. Demaine, M.L. Demaine, S.P.
    Fekete, L. Kleist, I. Kostitsyna, M. Löffler, Z. Masárová, K. Mundilova, C. Schmidt,
    in:, Proceedings of the 31st Canadian Conference on Computational Geometry, Canadian
    Conference on Computational Geometry, 2019, pp. 164–170.
conference:
  end_date: 2019-08-10
  location: Edmonton, Canada
  name: 'CCCG: Canadian Conference in Computational Geometry'
  start_date: 2019-08-08
date_created: 2019-11-04T16:46:11Z
date_published: 2019-08-01T00:00:00Z
date_updated: 2023-08-04T10:57:42Z
day: '01'
department:
- _id: HeEd
external_id:
  arxiv:
  - '1910.09917'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://cccg.ca/proceedings/2019/proceedings.pdf
month: '08'
oa: 1
oa_version: Published Version
page: 164-170
publication: Proceedings of the 31st Canadian Conference on Computational Geometry
publication_status: published
publisher: Canadian Conference on Computational Geometry
quality_controlled: '1'
related_material:
  record:
  - id: '8317'
    relation: extended_version
    status: public
scopus_import: '1'
status: public
title: Folding polyominoes with holes into a cube
type: conference
user_id: D865714E-FA4E-11E9-B85B-F5C5E5697425
year: '2019'
...
---
_id: '5986'
abstract:
- lang: eng
  text: "Given a triangulation of a point set in the plane, a flip deletes an edge
    e whose removal leaves a convex quadrilateral, and replaces e by the opposite
    diagonal of the quadrilateral. It is well known that any triangulation of a point
    set can be reconfigured to any other triangulation by some sequence of flips.
    We explore this question in the setting where each edge of a triangulation has
    a label, and a flip transfers the label of the removed edge to the new edge. It
    is not true that every labelled triangulation of a point set can be reconfigured
    to every other labelled triangulation via a sequence of flips, but we characterize
    when this is possible. There is an obvious necessary condition: for each label
    l, if edge e has label l in the first triangulation and edge f has label l in
    the second triangulation, then there must be some sequence of flips that moves
    label l from e to f, ignoring all other labels. Bose, Lubiw, Pathak and Verdonschot
    formulated the Orbit Conjecture, which states that this necessary condition is
    also sufficient, i.e. that all labels can be simultaneously mapped to their destination
    if and only if each label individually can be mapped to its destination. We prove
    this conjecture. Furthermore, we give a polynomial-time algorithm (with \U0001D442(\U0001D45B8)
    being a crude bound on the run-time) to find a sequence of flips to reconfigure
    one labelled triangulation to another, if such a sequence exists, and we prove
    an upper bound of \U0001D442(\U0001D45B7) on the length of the flip sequence.
    Our proof uses the topological result that the sets of pairwise non-crossing edges
    on a planar point set form a simplicial complex that is homeomorphic to a high-dimensional
    ball (this follows from a result of Orden and Santos; we give a different proof
    based on a shelling argument). The dual cell complex of this simplicial ball,
    called the flip complex, has the usual flip graph as its 1-skeleton. We use properties
    of the 2-skeleton of the flip complex to prove the Orbit Conjecture."
article_processing_charge: Yes (via OA deal)
article_type: original
arxiv: 1
author:
- first_name: Anna
  full_name: Lubiw, Anna
  last_name: Lubiw
- first_name: Zuzana
  full_name: Masárová, Zuzana
  id: 45CFE238-F248-11E8-B48F-1D18A9856A87
  last_name: Masárová
  orcid: 0000-0002-6660-1322
- first_name: Uli
  full_name: Wagner, Uli
  id: 36690CA2-F248-11E8-B48F-1D18A9856A87
  last_name: Wagner
  orcid: 0000-0002-1494-0568
citation:
  ama: Lubiw A, Masárová Z, Wagner U. A proof of the orbit conjecture for flipping
    edge-labelled triangulations. <i>Discrete &#38; Computational Geometry</i>. 2019;61(4):880-898.
    doi:<a href="https://doi.org/10.1007/s00454-018-0035-8">10.1007/s00454-018-0035-8</a>
  apa: Lubiw, A., Masárová, Z., &#38; Wagner, U. (2019). A proof of the orbit conjecture
    for flipping edge-labelled triangulations. <i>Discrete &#38; Computational Geometry</i>.
    Springer Nature. <a href="https://doi.org/10.1007/s00454-018-0035-8">https://doi.org/10.1007/s00454-018-0035-8</a>
  chicago: Lubiw, Anna, Zuzana Masárová, and Uli Wagner. “A Proof of the Orbit Conjecture
    for Flipping Edge-Labelled Triangulations.” <i>Discrete &#38; Computational Geometry</i>.
    Springer Nature, 2019. <a href="https://doi.org/10.1007/s00454-018-0035-8">https://doi.org/10.1007/s00454-018-0035-8</a>.
  ieee: A. Lubiw, Z. Masárová, and U. Wagner, “A proof of the orbit conjecture for
    flipping edge-labelled triangulations,” <i>Discrete &#38; Computational Geometry</i>,
    vol. 61, no. 4. Springer Nature, pp. 880–898, 2019.
  ista: Lubiw A, Masárová Z, Wagner U. 2019. A proof of the orbit conjecture for flipping
    edge-labelled triangulations. Discrete &#38; Computational Geometry. 61(4), 880–898.
  mla: Lubiw, Anna, et al. “A Proof of the Orbit Conjecture for Flipping Edge-Labelled
    Triangulations.” <i>Discrete &#38; Computational Geometry</i>, vol. 61, no. 4,
    Springer Nature, 2019, pp. 880–98, doi:<a href="https://doi.org/10.1007/s00454-018-0035-8">10.1007/s00454-018-0035-8</a>.
  short: A. Lubiw, Z. Masárová, U. Wagner, Discrete &#38; Computational Geometry 61
    (2019) 880–898.
date_created: 2019-02-14T11:54:08Z
date_published: 2019-06-01T00:00:00Z
date_updated: 2023-09-07T13:17:36Z
day: '01'
ddc:
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department:
- _id: UlWa
doi: 10.1007/s00454-018-0035-8
external_id:
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  - '1710.02741'
  isi:
  - '000466130000009'
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title: A proof of the orbit conjecture for flipping edge-labelled triangulations
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abstract:
- lang: eng
  text: 'Given a triangulation of a point set in the plane, a flip deletes an edge
    e whose removal leaves a convex quadrilateral, and replaces e by the opposite
    diagonal of the quadrilateral. It is well known that any triangulation of a point
    set can be reconfigured to any other triangulation by some sequence of flips.
    We explore this question in the setting where each edge of a triangulation has
    a label, and a flip transfers the label of the removed edge to the new edge. It
    is not true that every labelled triangulation of a point set can be reconfigured
    to every other labelled triangulation via a sequence of flips, but we characterize
    when this is possible. There is an obvious necessary condition: for each label
    l, if edge e has label l in the first triangulation and edge f has label l in
    the second triangulation, then there must be some sequence of flips that moves
    label l from e to f, ignoring all other labels. Bose, Lubiw, Pathak and Verdonschot
    formulated the Orbit Conjecture, which states that this necessary condition is
    also sufficient, i.e. that all labels can be simultaneously mapped to their destination
    if and only if each label individually can be mapped to its destination. We prove
    this conjecture. Furthermore, we give a polynomial-time algorithm to find a sequence
    of flips to reconfigure one labelled triangulation to another, if such a sequence
    exists, and we prove an upper bound of O(n7) on the length of the flip sequence.
    Our proof uses the topological result that the sets of pairwise non-crossing edges
    on a planar point set form a simplicial complex that is homeomorphic to a high-dimensional
    ball (this follows from a result of Orden and Santos; we give a different proof
    based on a shelling argument). The dual cell complex of this simplicial ball,
    called the flip complex, has the usual flip graph as its 1-skeleton. We use properties
    of the 2-skeleton of the flip complex to prove the Orbit Conjecture.'
alternative_title:
- LIPIcs
article_number: '49'
author:
- first_name: Anna
  full_name: Lubiw, Anna
  last_name: Lubiw
- first_name: Zuzana
  full_name: Masárová, Zuzana
  id: 45CFE238-F248-11E8-B48F-1D18A9856A87
  last_name: Masárová
  orcid: 0000-0002-6660-1322
- first_name: Uli
  full_name: Wagner, Uli
  id: 36690CA2-F248-11E8-B48F-1D18A9856A87
  last_name: Wagner
  orcid: 0000-0002-1494-0568
citation:
  ama: 'Lubiw A, Masárová Z, Wagner U. A proof of the orbit conjecture for flipping
    edge labelled triangulations. In: Vol 77. Schloss Dagstuhl - Leibniz-Zentrum für
    Informatik; 2017. doi:<a href="https://doi.org/10.4230/LIPIcs.SoCG.2017.49">10.4230/LIPIcs.SoCG.2017.49</a>'
  apa: 'Lubiw, A., Masárová, Z., &#38; Wagner, U. (2017). A proof of the orbit conjecture
    for flipping edge labelled triangulations (Vol. 77). Presented at the SoCG: Symposium
    on Computational Geometry, Brisbane, Australia: Schloss Dagstuhl - Leibniz-Zentrum
    für Informatik. <a href="https://doi.org/10.4230/LIPIcs.SoCG.2017.49">https://doi.org/10.4230/LIPIcs.SoCG.2017.49</a>'
  chicago: Lubiw, Anna, Zuzana Masárová, and Uli Wagner. “A Proof of the Orbit Conjecture
    for Flipping Edge Labelled Triangulations,” Vol. 77. Schloss Dagstuhl - Leibniz-Zentrum
    für Informatik, 2017. <a href="https://doi.org/10.4230/LIPIcs.SoCG.2017.49">https://doi.org/10.4230/LIPIcs.SoCG.2017.49</a>.
  ieee: 'A. Lubiw, Z. Masárová, and U. Wagner, “A proof of the orbit conjecture for
    flipping edge labelled triangulations,” presented at the SoCG: Symposium on Computational
    Geometry, Brisbane, Australia, 2017, vol. 77.'
  ista: 'Lubiw A, Masárová Z, Wagner U. 2017. A proof of the orbit conjecture for
    flipping edge labelled triangulations. SoCG: Symposium on Computational Geometry,
    LIPIcs, vol. 77, 49.'
  mla: Lubiw, Anna, et al. <i>A Proof of the Orbit Conjecture for Flipping Edge Labelled
    Triangulations</i>. Vol. 77, 49, Schloss Dagstuhl - Leibniz-Zentrum für Informatik,
    2017, doi:<a href="https://doi.org/10.4230/LIPIcs.SoCG.2017.49">10.4230/LIPIcs.SoCG.2017.49</a>.
  short: A. Lubiw, Z. Masárová, U. Wagner, in:, Schloss Dagstuhl - Leibniz-Zentrum
    für Informatik, 2017.
conference:
  end_date: 2017-07-07
  location: Brisbane, Australia
  name: 'SoCG: Symposium on Computational Geometry'
  start_date: 2017-07-04
date_created: 2018-12-11T11:47:54Z
date_published: 2017-06-01T00:00:00Z
date_updated: 2023-09-05T15:01:43Z
day: '01'
ddc:
- '514'
- '516'
department:
- _id: UlWa
doi: 10.4230/LIPIcs.SoCG.2017.49
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publication_status: published
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title: A proof of the orbit conjecture for flipping edge labelled triangulations
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