10 citations · 11 across the 18 of their papers we have counts for
23 papers
Continuous Computational Social Choice: A Case Study in Bribery
Martin Koutecký, Nikolaos Melissinos, Tung Anh Vu +1
Computational social choice seeks algorithmic answers to questions about preference aggregation, safety of elections, robustness of outcomes, stability, etc. It overwhelmingly mode…
Individual Rationality in Constrained Hedonic Games: Additively Separable and Fractional Preferences
Foivos Fioravantes, Harmender Gahlawat, Nikolaos Melissinos +1
Hedonic games are an archetypal problem in coalition formation, where a set of selfish agents want to partition themselves into stable coalitions. In this work, we focus on two nat…
Game-Theoretic and Algorithmic Analyses of Multi-Agent Routing under Crossing Costs
Tesshu Hanaka, Nikolaos Melissinos, Hirotaka Ono
Coordinating the movement of multiple autonomous agents over a shared network is a fundamental challenge in algorithmic robotics, intelligent transportation, and distributed system…
Exact Algorithms for Resource Reallocation Under Budgetary Constraints
Arun Kumar Das, Sandip Das, Sweta Das +2
Efficient resource (re-)allocation is a critical challenge in optimizing productivity and sustainability within multi-party supply networks. In this work, we introduce the \textsc{…
When Agents Break Down in Multiagent Path Finding
Foivos Fioravantes, Dušan Knop, Nikolaos Melissinos +1
In Multiagent Path Finding (MAPF), the goal is to compute efficient, collision-free paths for multiple agents navigating a network from their sources to targets, minimizing the sch…
Structural Parameters for Steiner Orientation
Tesshu Hanaka, Michael Lampis, Nikolaos Melissinos +3
We consider the \textsc{Steiner Orientation} problem, where we are given as input a mixed graph and a set of demand pairs , . The goal is to ori…
Parameterized Critical Node Cut Revisited
Dušan Knop, Nikolaos Melissinos, Manolis Vasilakis
We study how to sparsify connectivity in graphs under a tight deletion budget. Given a graph and integers , Critical Node Cut (CNC) asks whether we can delete at mos…
Exact Algorithms and Lower Bounds for Forming Coalitions of Constrained Maximum Size
Foivos Fioravantes, Harmender Gahlawat, Nikolaos Melissinos
Imagine we want to split a group of agents into teams in the most \emph{efficient} way, considering that each agent has their own preferences about their teammates. This scenario i…
Exact Algorithms for Distance to Unique Vertex Cover
Foivos Fioravantes, Dušan Knop, Nikolaos Melissinos +2
Horiyama et al. (AAAI 2024) studied the problem of generating graph instances that possess a unique minimum vertex cover under specific conditions. Their approach involved pre-assi…
Satisfactory Budget Division
Laurent Gourvès, Michael Lampis, Nikolaos Melissinos +1
A divisible budget must be allocated to several projects, and agents are asked for their opinion on how much they would give to each project. We consider that an agent is satisfied…
Solving Multiagent Path Finding on Highly Centralized Networks
Foivos Fioravantes, Dušan Knop, Jan Matyáš Křišťan +3
The Mutliagent Path Finding (MAPF) problem consists of identifying the trajectories that a set of agents should follow inside a given network in order to reach their desired destin…
Exact Algorithms for Multiagent Path Finding with Communication Constraints on Tree-Like Structures
Foivos Fioravantes, Dušan Knop, Jan Matyáš Křišťan +2
Consider the scenario where multiple agents have to move in an optimal way through a network, each one towards their ending position while avoiding collisions. By optimal, we mean…
Exact Algorithms and Lowerbounds for Multiagent Pathfinding: Power of Treelike Topology
Foivos Fioravantes, Dušan Knop, Jan Matyáš Křišťan +2
In the Multiagent Path Finding problem (MAPF for short), we focus on efficiently finding non-colliding paths for a set of agents on a given graph , where each agent seeks a…
Bandwidth Parameterized by Cluster Vertex Deletion Number
Tatsuya Gima, Eun Jung Kim, Noleen Köhler +2
Given a graph and an integer , Bandwidth asks whether there exists a bijection from to such that $\max_{\{u, v \} \in E(G)} | π(u) - π(v)…
Parameterised distance to local irregularity
Foivos Fioravantes, Nikolaos Melissinos, Theofilos Triommatis
A graph is \emph{locally irregular} if no two of its adjacent vertices have the same degree. In [Fioravantes et al. Complexity of finding maximum locally irregular induced subg…
Odd Chromatic Number of Graph Classes
Rémy Belmonte, Ararat Harutyunyan, Noleen Köhler +1
A graph is called odd (respectively, even) if every vertex has odd (respectively, even) degree. Gallai proved that every graph can be partitioned into two even induced subgraphs, o…
Parameterized Max Min Feedback Vertex Set
Michael Lampis, Nikolaos Melissinos, Manolis Vasilakis
Given a graph and an integer , Max Min FVS asks whether there exists a minimal set of vertices of size at least whose deletion destroys all cycles. We present several re…
Approximating Subset Sum Ratio via Partition Computations
Giannis Alonistiotis, Antonis Antonopoulos, Nikolaos Melissinos +3
We present a new FPTAS for the Subset Sum Ratio problem, which, given a set of integers, asks for two disjoint subsets such that the ratio of their sums is as close to as possi…
Filling Crosswords is Very Hard
Laurent Gourvès, Ararat Harutyunyan, Michael Lampis +1
We revisit a classical crossword filling puzzle which already appeared in Garey\&Jonhson's book. We are given a grid with vertical and horizontal slots and a dictionary with $m…
Digraph Coloring and Distance to Acyclicity
Ararat Harutyunyan, Michael Lampis, Nikolaos Melissinos
In -Digraph Coloring we are given a digraph and are asked to partition its vertices into at most sets, so that each set induces a DAG. This well-known problem is NP-hard, as…
(In)approximability of Maximum Minimal FVS
Louis Dublois, Tesshu Hanaka, Mehdi Khosravian Ghadikolaei +2
We study the approximability of the NP-complete \textsc{Maximum Minimal Feedback Vertex Set} problem. Informally, this natural problem seems to lie in an intermediate space between…
Approximation Schemes for Subset Sum Ratio Problems
Nikolaos Melissinos, Aris Pagourtzis, Theofilos Triommatis
We consider the Subset Sum Ratio Problem (), in which given a set of integers the goal is to find two subsets such that the ratio of their sums is as close to~1 as possible, a…
A Faster FPTAS for the Subset-Sums Ratio Problem
Nikolaos Melissinos, Aris Pagourtzis
The Subset-Sums Ratio problem (SSR) is an optimization problem in which, given a set of integers, the goal is to find two subsets such that the ratio of their sums is as close to 1…