Improved distance sensitivity oracles with subcubic preprocessing time

نویسندگان

چکیده

We consider the problem of building distance sensitivity oracles (DSOs). Given a directed graph G = ( V , E ) with edge weights in { 1 2 … M } we need to preprocess it into data structure, and answer following queries: given vertices u v ∈ failed vertex or f ∪ output length shortest path from that does not go through . Our main result is simple DSO O ˜ n 2.7233 preprocessing time query time. Moreover, if input undirected, can be improved 2.6865 The algorithm randomized correct probability ≥ − / C for constant made arbitrarily large. This improves previous best 2.8729 polylog [STOC'20].

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Approximate distance oracles with improved preprocessing time

Given an undirected graph G with m edges, n vertices, and non-negative edge weights, and given an integer k ≥ 1, we show that for some universal constant c, a (2k − 1)approximate distance oracle for G of size O(kn) can be constructed in O( √ km+kn √ ) time and can answer queries in O(k) time. We also give an oracle which is faster for smaller k. Our results break the quadratic preprocessing tim...

متن کامل

Approximate Distance Oracles with Improved Query Time

Given an undirected graph G with m edges, n vertices, and non-negative edge weights, and given an integer k ≥ 2, we show that a (2k − 1)-approximate distance oracle for G of size O(kn) and with O(log k) query time can be constructed in O(min{kmn1/k, √ km+kn √ k}) time for some constant c. This improves the O(k) query time of Thorup and Zwick. Furthermore, for any 0 < ǫ ≤ 1, we give an oracle of...

متن کامل

Improved Distance Sensitivity Oracles via Tree Partitioning

We introduce an improved structure of distance sensitivity oracle (DSO). The task is to pre-process a non-negatively weighted graph so that a data structure can quickly answer replacement path length for every triple of source, terminal and failed vertex. The previous best algorithm constructs in time Õ(mn) a distance sensitivity oracle of size O(n logn) that processes queries in O(1) time. As ...

متن کامل

Approximate Distance Oracles for Planar Graphs with Improved Query Time-Space Tradeoff

We consider approximate distance oracles for edge-weighted n-vertex undirected planar graphs. Given fixed ǫ > 0, we present a (1 + ǫ)-approximate distance oracle with O(n(log logn)) space and O((log logn)) query time. This improves the previous best product of query time and space of the oracles of Thorup (FOCS 2001, J. ACM 2004) and Klein (SODA 2002) from O(n log n) to O(n(log log n)).

متن کامل

Distance Oracles For Time-Dependent Road Networks

vi Εκτεταμένη Περίληψη viii

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

ژورنال

عنوان ژورنال: Journal of Computer and System Sciences

سال: 2022

ISSN: ['1090-2724', '0022-0000']

DOI: https://doi.org/10.1016/j.jcss.2021.08.005