| IEICE Technical Committee Submission System Conference Paper's Information |
Online Proceedings [Sign in] Tech. Rep. Archives |
| Go Top Page | Go Previous | [Japanese] / [English] |
| Paper Abstract and Keywords | ||
| Presentation | 2021-12-03 11:10 Token Sliding on Directed Graphs Takehiro Ito (Tohoku Univ), Yuni Iwamasa, Yasuaki Kobayashi (Kyoto Univ), Yu Nakahata (NAIST), Masahiro Takahashi (Kyoto Univ), Yota Otachi (Nagoya Univ), Kunihiro Wasa (Toyohashi Tech)  COMP2021-23 |
|
| Abstract | (in Japanese) | (See Japanese page) |
| (in English) | given a directed graph and two sets of pairwise nonadjacent vertices, whether one can reach from one set to the other by repeatedly applying a local operation that exchanges a vertex in the current set with one of its out-neighbors, while keeping the nonadjacency. It can be seen as a reconfiguration process where a token is placed on each vertex in the current set, and the local operation slides a token along an arc respecting its direction. Previously, such a problem was extensively studied on undirected graphs, where the edges have no directions and thus the local operation is symmetric. textsc{Directed Token Sliding} is a generalization of its undirected variant since an undirected edge can be simulated by two arcs of opposite directions. In this paper, we initiate the algorithmic study of textsc{Directed Token Sliding}. We first observe that the problem is PSPACE-complete even if we forbid parallel arcs in opposite directions and that the problem on directed acyclic graphs is NP-complete and W[1]-hard parameterized by the size of the sets in consideration. We then show our main result: a linear-time algorithm for the problem on directed graphs whose underlying undirected graphs are trees, which are called polytrees. Such a result is also known for the undirected variant of the problem on trees~[Demaine et al.~TCS 2015], but the techniques used here are quite different because of the asymmetric nature of the directed problem. We present a characterization of yes-instances based on the existence of a certain set of directed paths, and then derive simple equivalent conditions from it by some observations, which admits an efficient algorithm. For the polytree case, we also present a quadratic-time algorithm that outputs, if the input is a yes-instance, one of the shortest reconfiguration sequences. |
|
| Keyword | (in Japanese) | (See Japanese page) |
| (in English) | / / / / / / / | |
| Reference Info. | IEICE Tech. Rep., vol. 121, no. 285, COMP2021-23, pp. 11-18, Dec. 2021. | |
| Paper # | COMP2021-23 | |
| Date of Issue | 2021-11-26 (COMP) | |
| ISSN | Online edition: ISSN 2432-6380 | |
| Copyright and reproduction |
All rights are reserved and no part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopy, recording, or any information storage and retrieval system, without permission in writing from the publisher. Notwithstanding, instructors are permitted to photocopy isolated articles for noncommercial classroom use without fee. (License No.: 10GA0019/12GB0052/13GB0056/17GB0034/18GB0034) | |
| Download PDF | COMP2021-23 |
|
| Conference Information | |
| Committee | COMP |
| Conference Date | 2021-12-03 - 2021-12-03 |
| Place (in Japanese) | (See Japanese page) |
| Place (in English) | Kanazawa Chamber of Commerce and Industry |
| Topics (in Japanese) | (See Japanese page) |
| Topics (in English) | |
| Paper Information | |
| Registration To | COMP |
| Conference Code | 2021-12-COMP |
| Language | English |
| Title (in Japanese) | (See Japanese page) |
| Sub Title (in Japanese) | (See Japanese page) |
| Title (in English) | Token Sliding on Directed Graphs |
| Sub Title (in English) | |
| Keyword(1) | |
| Keyword(2) | |
| Keyword(3) | |
| Keyword(4) | |
| Keyword(5) | |
| Keyword(6) | |
| Keyword(7) | |
| Keyword(8) | |
| 1st Author's Name | Takehiro Ito |
| 1st Author's Affiliation | Tohoku University (Tohoku Univ) |
| 2nd Author's Name | Yuni Iwamasa |
| 2nd Author's Affiliation | Kyoto University (Kyoto Univ) |
| 3rd Author's Name | Yasuaki Kobayashi |
| 3rd Author's Affiliation | Kyoto University (Kyoto Univ) |
| 4th Author's Name | Yu Nakahata |
| 4th Author's Affiliation | Nara Institute of Science and Technology (NAIST) |
| 5th Author's Name | Masahiro Takahashi |
| 5th Author's Affiliation | Kyoto University (Kyoto Univ) |
| 6th Author's Name | Yota Otachi |
| 6th Author's Affiliation | Nagoya University (Nagoya Univ) |
| 7th Author's Name | Kunihiro Wasa |
| 7th Author's Affiliation | Toyohashi University of Technology (Toyohashi Tech) |
| 8th Author's Name | |
| 8th Author's Affiliation | () |
| 9th Author's Name | |
| 9th Author's Affiliation | () |
| 10th Author's Name | |
| 10th Author's Affiliation | () |
| 11th Author's Name | |
| 11th Author's Affiliation | () |
| 12th Author's Name | |
| 12th Author's Affiliation | () |
| 13th Author's Name | |
| 13th Author's Affiliation | () |
| 14th Author's Name | |
| 14th Author's Affiliation | () |
| 15th Author's Name | |
| 15th Author's Affiliation | () |
| 16th Author's Name | |
| 16th Author's Affiliation | () |
| 17th Author's Name | |
| 17th Author's Affiliation | () |
| 18th Author's Name | |
| 18th Author's Affiliation | () |
| Speaker | Author-5 |
| Date Time | 2021-12-03 11:10:00 |
| Presentation Time | 30 minutes |
| Registration for | COMP |
| Paper # | COMP2021-23 |
| Volume (vol) | vol.121 |
| Number (no) | no.285 |
| Page | pp.11-18 |
| #Pages | 8 |
| Date of Issue | 2021-11-26 (COMP) |
[Return to Top Page]