The Steiner tree problem asks for the shortest tree connecting
a given set of terminal points in a metric space. We design
new approximation algorithms for the Steiner tree problems
using a novel technique of choosing Steiner points in dependence
on the possible deviation from ... more >>>

We consider combinatorial avoidance and achievement games
based on graph Ramsey theory: The players take turns in coloring
still uncolored edges of a graph G, each player being assigned a
distinct color, choosing one edge per move. In avoidance games,
completing a monochromatic subgraph isomorphic to ... more >>>

Finding exact circuit size is a notorious optimization problem in practice. Whereas modern computers and algorithmic techniques allow to find a circuit of size seven in blink of an eye, it may take more than a week to search for a circuit of size thirteen. One of the reasons of ... more >>>