Yuni Iwamasa

activity

20202024

collaborators

7 papers

math.CO2024

Basis sequence reconfiguration in the union of matroids

Tesshu Hanaka, Yuni Iwamasa, Yasuaki Kobayashi +2

Given a graph $G$ and two spanning trees $T$ and $T^{'}$ in $G$ , Spanning Tree Reconfiguration asks whether there is a step-by-step transformation from $T$ to $T^{'}$ such that all inter…

math.CO2022

Reconfiguration of colorings in triangulations of the sphere

Takehiro Ito, Yuni Iwamasa, Yusuke Kobayashi +4

In 1973, Fisk proved that any $4$ -coloring of a $3$ -colorable triangulation of the $2$ -sphere can be obtained from any $3$ -coloring by a sequence of Kempe-changes. On the other han…

cs.DS2022

Rerouting Planar Curves and Disjoint Paths

Takehiro Ito, Yuni Iwamasa, Naonori Kakimura +5

In this paper, we consider a transformation of $k$ disjoint paths in a graph. For a graph and a pair of $k$ disjoint paths $P$ and $Q$ connecting the same set o…

cs.DS2022

Independent set reconfiguration on directed graphs

Takehiro Ito, Yuni Iwamasa, Yasuaki Kobayashi +4

\textsc{Directed Token Sliding} asks, given a directed graph and two sets of pairwise nonadjacent vertices, whether one can reach from one set to the other by repeatedly applying a…

math.CO2021

Monotone edge flips to an orientation of maximum edge-connectivity à la Nash-Williams

Takehiro Ito, Yuni Iwamasa, Naonori Kakimura +6

We initiate the study of $k$ -edge-connected orientations of undirected graphs through edge flips for $k \geq 2$ . We prove that in every orientation of an undirected $2 k$ -edge-conne…