---
_id: '65733'
abstract:
- lang: eng
  text: "<jats:title>Abstract</jats:title>\r\n                  <jats:p>\r\n                    In
    this paper, we study the computation of shortest paths within the\r\n                    <jats:italic>geometric
    amoebot model</jats:italic>\r\n                    , a commonly used model for
    programmable matter. Shortest paths are essential for various tasks and therefore
    have been heavily investigated in many different contexts. We consider the\r\n
    \                   <jats:italic>reconfigurable circuit extension</jats:italic>\r\n
    \                   of the model where the amoebot structure is able to interconnect
    amoebots by so-called circuits. These circuits permit the instantaneous transmission
    of simple signals between connected amoebots. We propose distributed algorithms
    for the\r\n                    <jats:italic>shortest path forest problem</jats:italic>\r\n
    \                   where, given a set of\r\n                    <jats:italic>k</jats:italic>\r\n
    \                   sources and a set of\r\n                    <jats:inline-formula>\r\n
    \                     <jats:alternatives>\r\n                        <jats:tex-math>$$\\ell
    $$</jats:tex-math>\r\n                        <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\">\r\n
    \                         <mml:mi>ℓ</mml:mi>\r\n                        </mml:math>\r\n
    \                     </jats:alternatives>\r\n                    </jats:inline-formula>\r\n
    \                   destinations, the amoebot structure has to compute a forest
    that connects each destination to its closest source on a shortest path. Our main
    results are two algorithms for hole-free structures. The first algorithm constructs
    a shortest path tree for a single source within\r\n                    <jats:inline-formula>\r\n
    \                     <jats:alternatives>\r\n                        <jats:tex-math>$$O(\\log
    \\ell )$$</jats:tex-math>\r\n                        <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\">\r\n
    \                         <mml:mrow>\r\n                            <mml:mi>O</mml:mi>\r\n
    \                           <mml:mo>(</mml:mo>\r\n                            <mml:mo>log</mml:mo>\r\n
    \                           <mml:mi>ℓ</mml:mi>\r\n                            <mml:mo>)</mml:mo>\r\n
    \                         </mml:mrow>\r\n                        </mml:math>\r\n
    \                     </jats:alternatives>\r\n                    </jats:inline-formula>\r\n
    \                   rounds, and the second algorithm a shortest path forest for
    an arbitrary number of sources within\r\n                    <jats:inline-formula>\r\n
    \                     <jats:alternatives>\r\n                        <jats:tex-math>$$O(\\log
    n \\log ^2 k)$$</jats:tex-math>\r\n                        <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\">\r\n
    \                         <mml:mrow>\r\n                            <mml:mi>O</mml:mi>\r\n
    \                           <mml:mo>(</mml:mo>\r\n                            <mml:mo>log</mml:mo>\r\n
    \                           <mml:mi>n</mml:mi>\r\n                            <mml:msup>\r\n
    \                             <mml:mo>log</mml:mo>\r\n                              <mml:mn>2</mml:mn>\r\n
    \                           </mml:msup>\r\n                            <mml:mi>k</mml:mi>\r\n
    \                           <mml:mo>)</mml:mo>\r\n                          </mml:mrow>\r\n
    \                       </mml:math>\r\n                      </jats:alternatives>\r\n
    \                   </jats:inline-formula>\r\n                    rounds. The
    former algorithm also provides an\r\n                    <jats:italic>O</jats:italic>\r\n
    \                   (1) rounds solution for the\r\n                    <jats:italic>single
    pair shortest path problem</jats:italic>\r\n                    (SPSP) and an\r\n
    \                   <jats:inline-formula>\r\n                      <jats:alternatives>\r\n
    \                       <jats:tex-math>$$O(\\log n)$$</jats:tex-math>\r\n                        <mml:math
    xmlns:mml=\"http://www.w3.org/1998/Math/MathML\">\r\n                          <mml:mrow>\r\n
    \                           <mml:mi>O</mml:mi>\r\n                            <mml:mo>(</mml:mo>\r\n
    \                           <mml:mo>log</mml:mo>\r\n                            <mml:mi>n</mml:mi>\r\n
    \                           <mml:mo>)</mml:mo>\r\n                          </mml:mrow>\r\n
    \                       </mml:math>\r\n                      </jats:alternatives>\r\n
    \                   </jats:inline-formula>\r\n                    rounds solution
    for the\r\n                    <jats:italic>single source shortest path problem</jats:italic>\r\n
    \                   (SSSP) since these problems are special cases of the considered
    problem. Then, we adapt the latter algorithm to an offset version of the problem.
    This allows us to solve the problem for amoebot structures with holes within\r\n
    \                   <jats:inline-formula>\r\n                      <jats:alternatives>\r\n
    \                       <jats:tex-math>$$O(h \\log ^3 n)$$</jats:tex-math>\r\n
    \                       <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\">\r\n
    \                         <mml:mrow>\r\n                            <mml:mi>O</mml:mi>\r\n
    \                           <mml:mo>(</mml:mo>\r\n                            <mml:mi>h</mml:mi>\r\n
    \                           <mml:msup>\r\n                              <mml:mo>log</mml:mo>\r\n
    \                             <mml:mn>3</mml:mn>\r\n                            </mml:msup>\r\n
    \                           <mml:mi>n</mml:mi>\r\n                            <mml:mo>)</mml:mo>\r\n
    \                         </mml:mrow>\r\n                        </mml:math>\r\n
    \                     </jats:alternatives>\r\n                    </jats:inline-formula>\r\n
    \                   rounds w.h.p. where\r\n                    <jats:italic>h</jats:italic>\r\n
    \                   denotes the number of holes.\r\n                  </jats:p>"
article_number: '15'
author:
- first_name: Andreas
  full_name: Padalkin, Andreas
  id: '88238'
  last_name: Padalkin
- first_name: Christian
  full_name: Scheideler, Christian
  id: '20792'
  last_name: Scheideler
citation:
  ama: Padalkin A, Scheideler C. Polylogarithmic time algorithms for shortest path
    forests in programmable matter. <i>Distributed Computing</i>. 2026;39(2). doi:<a
    href="https://doi.org/10.1007/s00446-026-00505-2">10.1007/s00446-026-00505-2</a>
  apa: Padalkin, A., &#38; Scheideler, C. (2026). Polylogarithmic time algorithms
    for shortest path forests in programmable matter. <i>Distributed Computing</i>,
    <i>39</i>(2), Article 15. <a href="https://doi.org/10.1007/s00446-026-00505-2">https://doi.org/10.1007/s00446-026-00505-2</a>
  bibtex: '@article{Padalkin_Scheideler_2026, title={Polylogarithmic time algorithms
    for shortest path forests in programmable matter}, volume={39}, DOI={<a href="https://doi.org/10.1007/s00446-026-00505-2">10.1007/s00446-026-00505-2</a>},
    number={215}, journal={Distributed Computing}, publisher={Springer Science and
    Business Media LLC}, author={Padalkin, Andreas and Scheideler, Christian}, year={2026}
    }'
  chicago: Padalkin, Andreas, and Christian Scheideler. “Polylogarithmic Time Algorithms
    for Shortest Path Forests in Programmable Matter.” <i>Distributed Computing</i>
    39, no. 2 (2026). <a href="https://doi.org/10.1007/s00446-026-00505-2">https://doi.org/10.1007/s00446-026-00505-2</a>.
  ieee: 'A. Padalkin and C. Scheideler, “Polylogarithmic time algorithms for shortest
    path forests in programmable matter,” <i>Distributed Computing</i>, vol. 39, no.
    2, Art. no. 15, 2026, doi: <a href="https://doi.org/10.1007/s00446-026-00505-2">10.1007/s00446-026-00505-2</a>.'
  mla: Padalkin, Andreas, and Christian Scheideler. “Polylogarithmic Time Algorithms
    for Shortest Path Forests in Programmable Matter.” <i>Distributed Computing</i>,
    vol. 39, no. 2, 15, Springer Science and Business Media LLC, 2026, doi:<a href="https://doi.org/10.1007/s00446-026-00505-2">10.1007/s00446-026-00505-2</a>.
  short: A. Padalkin, C. Scheideler, Distributed Computing 39 (2026).
date_created: 2026-05-29T12:11:32Z
date_updated: 2026-05-29T12:13:09Z
department:
- _id: '34'
- _id: '7'
- _id: '79'
doi: 10.1007/s00446-026-00505-2
intvolume: '        39'
issue: '2'
language:
- iso: eng
publication: Distributed Computing
publication_identifier:
  issn:
  - 0178-2770
  - 1432-0452
publication_status: published
publisher: Springer Science and Business Media LLC
status: public
title: Polylogarithmic time algorithms for shortest path forests in programmable matter
type: journal_article
user_id: '15578'
volume: 39
year: '2026'
...
---
_id: '3872'
abstract:
- lang: eng
  text: 'This paper considers the problem of how to efficiently share a wireless medium
    which is subject to harsh external interference or even jamming. So far, this
    problem is understood only in simplistic single-hop or unit disk graph models.
    We in this paper initiate the study of MAC protocols for the SINR interference
    model (a.k.a. physical model). This paper makes two contributions. First, we introduce
    a new adversarial SINR model which captures a wide range of interference phenomena.
    Concretely, we consider a powerful, adaptive adversary which can jam nodes at
    arbitrary times and which is only limited by some energy budget. Our second contribution
    is a distributed MAC protocol called Sade which provably achieves a constant competitive
    throughput in this environment: we show that, with high probability, the protocol
    ensures that a constant fraction of the non-blocked time periods is used for successful
    transmissions.'
author:
- first_name: Adrian
  full_name: Ogierman, Adrian
  last_name: Ogierman
- first_name: Andrea
  full_name: Richa, Andrea
  last_name: Richa
- first_name: Christian
  full_name: Scheideler, Christian
  id: '20792'
  last_name: Scheideler
- first_name: Stefan
  full_name: Schmid, Stefan
  last_name: Schmid
- first_name: Jin
  full_name: Zhang, Jin
  last_name: Zhang
citation:
  ama: 'Ogierman A, Richa A, Scheideler C, Schmid S, Zhang J. Sade: competitive MAC
    under adversarial SINR. <i>Distributed Computing</i>. 2017;31(3):241-254. doi:<a
    href="https://doi.org/10.1007/s00446-017-0307-1">10.1007/s00446-017-0307-1</a>'
  apa: 'Ogierman, A., Richa, A., Scheideler, C., Schmid, S., &#38; Zhang, J. (2017).
    Sade: competitive MAC under adversarial SINR. <i>Distributed Computing</i>, <i>31</i>(3),
    241–254. <a href="https://doi.org/10.1007/s00446-017-0307-1">https://doi.org/10.1007/s00446-017-0307-1</a>'
  bibtex: '@article{Ogierman_Richa_Scheideler_Schmid_Zhang_2017, title={Sade: competitive
    MAC under adversarial SINR}, volume={31}, DOI={<a href="https://doi.org/10.1007/s00446-017-0307-1">10.1007/s00446-017-0307-1</a>},
    number={3}, journal={Distributed Computing}, publisher={Springer Nature}, author={Ogierman,
    Adrian and Richa, Andrea and Scheideler, Christian and Schmid, Stefan and Zhang,
    Jin}, year={2017}, pages={241–254} }'
  chicago: 'Ogierman, Adrian, Andrea Richa, Christian Scheideler, Stefan Schmid, and
    Jin Zhang. “Sade: Competitive MAC under Adversarial SINR.” <i>Distributed Computing</i>
    31, no. 3 (2017): 241–54. <a href="https://doi.org/10.1007/s00446-017-0307-1">https://doi.org/10.1007/s00446-017-0307-1</a>.'
  ieee: 'A. Ogierman, A. Richa, C. Scheideler, S. Schmid, and J. Zhang, “Sade: competitive
    MAC under adversarial SINR,” <i>Distributed Computing</i>, vol. 31, no. 3, pp.
    241–254, 2017.'
  mla: 'Ogierman, Adrian, et al. “Sade: Competitive MAC under Adversarial SINR.” <i>Distributed
    Computing</i>, vol. 31, no. 3, Springer Nature, 2017, pp. 241–54, doi:<a href="https://doi.org/10.1007/s00446-017-0307-1">10.1007/s00446-017-0307-1</a>.'
  short: A. Ogierman, A. Richa, C. Scheideler, S. Schmid, J. Zhang, Distributed Computing
    31 (2017) 241–254.
date_created: 2018-08-10T07:05:12Z
date_updated: 2022-01-06T06:59:47Z
department:
- _id: '79'
doi: 10.1007/s00446-017-0307-1
intvolume: '        31'
issue: '3'
page: 241-254
publication: Distributed Computing
publication_identifier:
  issn:
  - 0178-2770
  - 1432-0452
publication_status: published
publisher: Springer Nature
status: public
title: 'Sade: competitive MAC under adversarial SINR'
type: journal_article
user_id: '15504'
volume: 31
year: '2017'
...
