Reachability in arborescence packings

نویسندگان

چکیده

Fortier et al. proposed several research problems on packing arborescences and settled some of them. Others were later solved by Matsuoka Tanigawa Gao Yang. The last open problem is in this article. We show how to turn an inductive idea used the latter two articles into a simple proof technique that allows relate previous results arborescence packings. prove strong version Edmonds’ theorem spanning implies Kamiyama, Katoh Takizawa’s result reachability Durand de Gevigney, Nguyen Szigeti’s matroid-based Király’s matroid-reachability-based arborescences. Further, we deduce new mixed hyperarborescences from due al.. Finally, deal with algorithmic aspects considered. first obtain algorithms find desired packings all settings then apply weighted matroid intersection algorithm also solutions minimizing given weight function.

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

Rainbow Arborescence in Random Digraphs

We consider the Erdős-Rényi random directed graph process, which is a stochastic process that starts with n vertices and no edges, and at each step adds one new directed edge chosen uniformly at random from the set of missing edges. Let D(n,m) be a graph with m edges obtained after m steps of this process. Each edge ei (i = 1, 2, . . . ,m) of D(n,m) independently chooses a colour, taken uniform...

متن کامل

The Gilbert arborescence problem

We investigate the problem of designing a minimum-cost flow network interconnecting n sources and a single sink, each with known locations in a normed space and with associated flow demands. The network may contain any finite number of additional unprescribed nodes from the space; these are known as the Steiner points. For concave increasing cost functions, a minimum cost network of this sort h...

متن کامل

Solving minimum-cost shared arborescence problems

In this work the minimum-cost shared network problem (MCSN) is introduced, where the objective is to find a minimum-cost subgraph, which is shared among multiple entities such that each entity is able to fulfil its own set of topological constraints. The topological constraints may induce structures like Steiner trees, minimum spanning trees, shortest paths, etc. The cost function to be minimiz...

متن کامل

Bilateral knee lipoma arborescence diagnosed by ultrasound.

Dear Editor, A 57-year-old Hispanic woman with no significant past medical history, presented to our clinic with a 5-year history of bilateral knee pain and swelling for which she had tried naproxen without much relief. Physical examination revealed a moderate effusion in the right supra-patellar region with a limited range of motion from 0 up to 100 . The left knee effusion was milder and rang...

متن کامل

Generation of Optimal Packings from Optimal Packings

We define two notions of generation between the various optimal packings Qm of m congruent disks in a subset K of R2. The first one that we call weak generation consists in getting Qn by removing m − n disks from Qm and by displacing the n remaining congruent disks which grow continuously and do not overlap. During a weak generation of Qn from Qm, we consider the contact graphs G(t) of the inte...

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: Discrete Applied Mathematics

سال: 2022

ISSN: ['1872-6771', '0166-218X']

DOI: https://doi.org/10.1016/j.dam.2022.05.018