activity
20242026
collaborators

6 papers

cs.DS2026

Frameworks to Design Approximation Algorithms for Finding Diverse Solutions in Combinatorial Problems

Tesshu Hanaka, Masashi Kiyomi, Yasuaki Kobayashi +4

Finding a \emph{single} best solution is the most common objective in combinatorial optimization problems. However, such a single solution may not be applicable to real-world probl…

cs.DS2025

Forcing a unique minimum spanning tree and a unique shortest path

Tatsuya Gima, Andreas Grigorjew, Yasuaki Kobayashi +8

A forcing set in a combinatorial problem is a set of elements such that there is a unique solution that contains all the elements in . An anti-forcing set is the symmetric c…

cs.DS2025

Broadcasting under Structural Restrictions

Yudai Egami, Tatsuya Gima, Tesshu Hanaka +7

In the Telephone Broadcast problem we are given a graph with a designated source vertex . Our goal is to transmit a message, which is initially known only to ,…

cs.DS2025

Finding a Minimum Spanning Tree with a Small Non-Terminal Set

Tesshu Hanaka, Yasuaki Kobayashi

In this paper, we study the problem of finding a minimum weight spanning tree that contains each vertex in a given subset of vertices as an internal vertex. This probl…

cs.DS2024

Structural Parameterizations of Vertex Integrity

Tatsuya Gima, Tesshu Hanaka, Yasuaki Kobayashi +3

The graph parameter vertex integrity measures how vulnerable a graph is to a removal of a small number of vertices. More precisely, a graph with small vertex integrity admits a sma…

math.CO2024

Basis sequence reconfiguration in the union of matroids

Tesshu Hanaka, Yuni Iwamasa, Yasuaki Kobayashi +2

Given a graph and two spanning trees and in , Spanning Tree Reconfiguration asks whether there is a step-by-step transformation from to such that all inter…