VOCAL 2024
Abstract Submission

72. Problems on Group-labeled Matroid Bases

Invited abstract in session WF-2: Combinatorial Optimization II, stream Discrete Optimization.

Wednesday, 16:45 - 18:15
Room: C 103

Authors (first author is the speaker)

1. Tamás Schwarcz
Department of Operations Research, Eötvös Loránd University
2. Florian Hörsch
CISPA
3. András Imolay
Eötvös Loránd University
4. Ryuhei Mizutani
The University of Tokyo
5. Taihei Oki
The University of Tokyo

Abstract

Several combinatorial optimization problems involve additional constraints, such as parity, congruency, and exact-weight constraints. These constraints are subsumed by group-label constraints defined as follows: given a labeling of a ground set to an abelian group and a prescribed set F of forbidden labels, we define a subset of the ground set F-avoiding if the sum of the labels of its elements is not in F. Non-zero and zero problems are particularly important special cases, where F consists of the zero and non-zero labels, respectively.

We study the problems of finding F-avoiding bases and common bases of two matroids. For the single matroid case, finding an F-avoiding basis is hard if F is part of the input, while for a fixed |F|, we show the polynomial solvability of the problem in several cases, including matroids representable over fixed, finite fields. Finding a zero common basis of two matroids is hard for any nontrivial group, while we show that the solvability of finding a non-zero basis depends on the group. Furthermore, if the group is finite, we give a randomized algebraic algorithm for finding an F-avoiding common basis of two matroids represented over the same field, with running time polynomial in |F| and the group size.

Keywords

Status: accepted


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