---
_id: '11768'
abstract:
- lang: eng
  text: "In the decremental single-source shortest paths (SSSP) problem, we want to
    maintain the distances between a given source node s and every other node in an
    n-node m-edge graph G undergoing edge deletions. While its static counterpart
    can be solved in near-linear time, this decremental problem is much more challenging
    even in the undirected unweighted case. In this case, the classic O(mn) total
    update time of Even and Shiloach [16] has been the fastest known algorithm for
    three decades. At the cost of a (1+ϵ)-approximation factor, the running time was
    recently improved to n2+o(1) by Bernstein and Roditty [9]. In this article, we
    bring the running time down to near-linear: We give a (1+ϵ)-approximation algorithm
    with m1+o(1) expected total update time, thus obtaining near-linear time. Moreover,
    we obtain m1+o(1) log W time for the weighted case, where the edge weights are
    integers from 1 to W. The only prior work on weighted graphs in o(mn) time is
    the mn0.9 + o(1)-time algorithm by Henzinger et al. [18, 19], which works for
    directed graphs with quasi-polynomial edge weights. The expected running time
    bound of our algorithm holds against an oblivious adversary.\r\n\r\nIn contrast
    to the previous results, which rely on maintaining a sparse emulator, our algorithm
    relies on maintaining a so-called sparse (h, ϵ)-hop set introduced by Cohen [12]
    in the PRAM literature. An (h, ϵ)-hop set of a graph G=(V, E) is a set F of weighted
    edges such that the distance between any pair of nodes in G can be (1+ϵ)-approximated
    by their h-hop distance (given by a path containing at most h edges) on G′=(V,
    E ∪ F). Our algorithm can maintain an (no(1), ϵ)-hop set of near-linear size in
    near-linear time under edge deletions. It is the first of its kind to the best
    of our knowledge. To maintain approximate distances using this hop set, we extend
    the monotone Even-Shiloach tree of Henzinger et al. [20] and combine it with the
    bounded-hop SSSP technique of Bernstein [4, 5] and Mądry [27]. These two new tools
    might be of independent interest."
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: Monika H
  full_name: Henzinger, Monika H
  id: 540c9bbd-f2de-11ec-812d-d04a5be85630
  last_name: Henzinger
  orcid: 0000-0002-5008-6530
- first_name: Sebastian
  full_name: Krinninger, Sebastian
  last_name: Krinninger
- first_name: Danupon
  full_name: Nanongkai, Danupon
  last_name: Nanongkai
citation:
  ama: Henzinger MH, Krinninger S, Nanongkai D. Decremental single-source shortest
    paths on undirected graphs in near-linear total update time. <i>Journal of the
    ACM</i>. 2018;65(6):1-40. doi:<a href="https://doi.org/10.1145/3218657">10.1145/3218657</a>
  apa: Henzinger, M. H., Krinninger, S., &#38; Nanongkai, D. (2018). Decremental single-source
    shortest paths on undirected graphs in near-linear total update time. <i>Journal
    of the ACM</i>. Association for Computing Machinery. <a href="https://doi.org/10.1145/3218657">https://doi.org/10.1145/3218657</a>
  chicago: Henzinger, Monika H, Sebastian Krinninger, and Danupon Nanongkai. “Decremental
    Single-Source Shortest Paths on Undirected Graphs in near-Linear Total Update
    Time.” <i>Journal of the ACM</i>. Association for Computing Machinery, 2018. <a
    href="https://doi.org/10.1145/3218657">https://doi.org/10.1145/3218657</a>.
  ieee: M. H. Henzinger, S. Krinninger, and D. Nanongkai, “Decremental single-source
    shortest paths on undirected graphs in near-linear total update time,” <i>Journal
    of the ACM</i>, vol. 65, no. 6. Association for Computing Machinery, pp. 1–40,
    2018.
  ista: Henzinger MH, Krinninger S, Nanongkai D. 2018. Decremental single-source shortest
    paths on undirected graphs in near-linear total update time. Journal of the ACM.
    65(6), 1–40.
  mla: Henzinger, Monika H., et al. “Decremental Single-Source Shortest Paths on Undirected
    Graphs in near-Linear Total Update Time.” <i>Journal of the ACM</i>, vol. 65,
    no. 6, Association for Computing Machinery, 2018, pp. 1–40, doi:<a href="https://doi.org/10.1145/3218657">10.1145/3218657</a>.
  short: M.H. Henzinger, S. Krinninger, D. Nanongkai, Journal of the ACM 65 (2018)
    1–40.
date_created: 2022-08-08T12:33:17Z
date_published: 2018-12-01T00:00:00Z
date_updated: 2023-02-21T16:30:41Z
day: '01'
doi: 10.1145/3218657
extern: '1'
external_id:
  arxiv:
  - '1512.08148'
intvolume: '        65'
issue: '6'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://arxiv.org/abs/1512.08148
month: '12'
oa: 1
oa_version: Preprint
page: 1-40
publication: Journal of the ACM
publication_identifier:
  eissn:
  - 1557-735X
  issn:
  - 0004-5411
publication_status: published
publisher: Association for Computing Machinery
quality_controlled: '1'
related_material:
  record:
  - id: '11855'
    relation: earlier_version
    status: public
scopus_import: '1'
status: public
title: Decremental single-source shortest paths on undirected graphs in near-linear
  total update time
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 65
year: '2018'
...
---
_id: '11769'
abstract:
- lang: eng
  text: "This paper solves a longstanding open problem in fully dynamic algorithms:
    We present the first fully dynamic algorithms that maintain connectivity, bipartiteness,
    and approximate minimum spanning trees in polylogarithmic time per edge insertion
    or deletion. The algorithms are designed using a new dynamic technique that combines
    a novel graph decomposition with randomization. They are Las-Vegas type randomized
    algorithms which use simple data structures and have a small constant factor.\r\nLet
    n denote the number of nodes in the graph. For a sequence of Ω(m0) operations,
    where m0 is the number of edges in the initial graph, the expected time for p
    updates is O(p log3 n) (througout the paper the logarithms are based 2) for connectivity
    and bipartiteness. The worst-case time for one query is O(log n/log log n). For
    the k-edge witness problem (“Does the removal of k given edges disconnect the
    graph?”) the expected time for p updates is O(p log3 n) and the expected time
    for q queries is O(qk log3 n). Given a graph with k different weights, the minimum
    spanning tree can be maintained during a sequence of p updates in expected time
    O(pk log3 n). This implies an algorithm to maintain a 1 + ε-approximation of the
    minimum spanning tree in expected time O((p log3 n logU)/ε) for p updates, where
    the weights of the edges are between 1 and U."
article_processing_charge: No
article_type: original
author:
- first_name: Monika H
  full_name: Henzinger, Monika H
  id: 540c9bbd-f2de-11ec-812d-d04a5be85630
  last_name: Henzinger
  orcid: 0000-0002-5008-6530
- first_name: Valerie
  full_name: King, Valerie
  last_name: King
citation:
  ama: Henzinger MH, King V. Randomized fully dynamic graph algorithms with polylogarithmic
    time per operation. <i>Journal of the ACM</i>. 1999;46(4):502-516. doi:<a href="https://doi.org/10.1145/320211.320215">10.1145/320211.320215</a>
  apa: Henzinger, M. H., &#38; King, V. (1999). Randomized fully dynamic graph algorithms
    with polylogarithmic time per operation. <i>Journal of the ACM</i>. Association
    for Computing Machinery. <a href="https://doi.org/10.1145/320211.320215">https://doi.org/10.1145/320211.320215</a>
  chicago: Henzinger, Monika H, and Valerie King. “Randomized Fully Dynamic Graph
    Algorithms with Polylogarithmic Time per Operation.” <i>Journal of the ACM</i>.
    Association for Computing Machinery, 1999. <a href="https://doi.org/10.1145/320211.320215">https://doi.org/10.1145/320211.320215</a>.
  ieee: M. H. Henzinger and V. King, “Randomized fully dynamic graph algorithms with
    polylogarithmic time per operation,” <i>Journal of the ACM</i>, vol. 46, no. 4.
    Association for Computing Machinery, pp. 502–516, 1999.
  ista: Henzinger MH, King V. 1999. Randomized fully dynamic graph algorithms with
    polylogarithmic time per operation. Journal of the ACM. 46(4), 502–516.
  mla: Henzinger, Monika H., and Valerie King. “Randomized Fully Dynamic Graph Algorithms
    with Polylogarithmic Time per Operation.” <i>Journal of the ACM</i>, vol. 46,
    no. 4, Association for Computing Machinery, 1999, pp. 502–16, doi:<a href="https://doi.org/10.1145/320211.320215">10.1145/320211.320215</a>.
  short: M.H. Henzinger, V. King, Journal of the ACM 46 (1999) 502–516.
date_created: 2022-08-08T12:50:25Z
date_published: 1999-07-01T00:00:00Z
date_updated: 2022-09-12T10:50:08Z
day: '01'
doi: 10.1145/320211.320215
extern: '1'
intvolume: '        46'
issue: '4'
language:
- iso: eng
month: '07'
oa_version: None
page: 502-516
publication: Journal of the ACM
publication_identifier:
  eissn:
  - 1557-735X
  issn:
  - 0004-5411
publication_status: published
publisher: Association for Computing Machinery
quality_controlled: '1'
scopus_import: '1'
status: public
title: Randomized fully dynamic graph algorithms with polylogarithmic time per operation
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 46
year: '1999'
...
---
_id: '4046'
abstract:
- lang: eng
  text: The main contribution of this work is an O(n log n + k)-time algorithm for
    computing all k intersections among n line segments in the plane. This time complexity
    is easily shown to be optimal. Within the same asymptotic cost, our algorithm
    can also construct the subdivision of the plane defined by the segments and compute
    which segment (if any) lies right above (or below) each intersection and each
    endpoint. The algorithm has been implemented and performs very well. The storage
    requirement is on the order of n + k in the worst case, but it is considerably
    lower in practice. To analyze the complexity of the algorithm, an amortization
    argument based on a new combinatorial theorem on line arrangements is used.
acknowledgement: "B, Chazelle wishes to acknowledge the National Science Foundation
  for supporting this research in part under Grant CCR 87-00917. H, Edelsbrunner is
  pleased to acknowledge the support of Amoco Fnd. Fac. Dev. Comput. Sci. 1-6-44862
  and the NSF under Grant CCR 87-14565. Permission to copy without fee all or part
  of this material is granted provided that the copies are not made or distributed
  for direct commercial advantage, the ACM copyright notice and the title of the publication
  and its date appear, and notice is given that copying is by permission of the Association
  for\r\nComputing Machinery. To copy otherwise, or to republish, requires a fee and/or
  specific permission."
article_processing_charge: No
article_type: original
author:
- first_name: Bernard
  full_name: Chazelle, Bernard
  last_name: Chazelle
- first_name: Herbert
  full_name: Edelsbrunner, Herbert
  id: 3FB178DA-F248-11E8-B48F-1D18A9856A87
  last_name: Edelsbrunner
  orcid: 0000-0002-9823-6833
citation:
  ama: Chazelle B, Edelsbrunner H. An optimal algorithm for intersecting line segments
    in the plane. <i>Journal of the ACM</i>. 1992;39(1):1-54. doi:<a href="https://doi.org/10.1145/147508.147511">10.1145/147508.147511</a>
  apa: Chazelle, B., &#38; Edelsbrunner, H. (1992). An optimal algorithm for intersecting
    line segments in the plane. <i>Journal of the ACM</i>. ACM. <a href="https://doi.org/10.1145/147508.147511">https://doi.org/10.1145/147508.147511</a>
  chicago: Chazelle, Bernard, and Herbert Edelsbrunner. “An Optimal Algorithm for
    Intersecting Line Segments in the Plane.” <i>Journal of the ACM</i>. ACM, 1992.
    <a href="https://doi.org/10.1145/147508.147511">https://doi.org/10.1145/147508.147511</a>.
  ieee: B. Chazelle and H. Edelsbrunner, “An optimal algorithm for intersecting line
    segments in the plane,” <i>Journal of the ACM</i>, vol. 39, no. 1. ACM, pp. 1–54,
    1992.
  ista: Chazelle B, Edelsbrunner H. 1992. An optimal algorithm for intersecting line
    segments in the plane. Journal of the ACM. 39(1), 1–54.
  mla: Chazelle, Bernard, and Herbert Edelsbrunner. “An Optimal Algorithm for Intersecting
    Line Segments in the Plane.” <i>Journal of the ACM</i>, vol. 39, no. 1, ACM, 1992,
    pp. 1–54, doi:<a href="https://doi.org/10.1145/147508.147511">10.1145/147508.147511</a>.
  short: B. Chazelle, H. Edelsbrunner, Journal of the ACM 39 (1992) 1–54.
date_created: 2018-12-11T12:06:37Z
date_published: 1992-01-01T00:00:00Z
date_updated: 2022-03-16T08:32:17Z
day: '01'
doi: 10.1145/147508.147511
extern: '1'
intvolume: '        39'
issue: '1'
language:
- iso: eng
main_file_link:
- url: https://dl.acm.org/doi/10.1145/147508.147511
month: '01'
oa_version: None
page: 1 - 54
publication: Journal of the ACM
publication_identifier:
  eissn:
  - 1557-735X
  issn:
  - 0004-5411
publication_status: published
publisher: ACM
publist_id: '2078'
quality_controlled: '1'
scopus_import: '1'
status: public
title: An optimal algorithm for intersecting line segments in the plane
type: journal_article
user_id: ea97e931-d5af-11eb-85d4-e6957dddbf17
volume: 39
year: '1992'
...
