---
_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'
...
