The goal of this textbook is twofold. First, the book serves as an introduction to the field of
parameterized algorithms and complexity accessible to graduate students and advanced …

Parameterization and approximation are two popular ways of coping with NP-hard
problems. More recently, the two have also been combined to derive many interesting …

We formulate a new hardness assumption, the Strongish Planted Clique Hypothesis
(SPCH), which postulates that any algorithm for planted clique must run in time $ n^{\Omega …

Abstract A Fixed-Parameter Tractable (FPT) ρ-approximation algorithm for a minimization
(resp. maximization) parameterized problem P is an FPT algorithm that, given an instance (x …

Given a directed graph $ G $ and a list $(s_1, t_1),\dots,(s_d, t_d) $ of terminal pairs, the
Directed Steiner Network problem asks for a minimum-cost subgraph of $ G $ that contains a …

Given a vertex-weighted directed graph G=(V,E) and a set T={t_1,t_2,...,t_k\} of k terminals,
the objective of the Strongly Connected Steiner Subgraph (SCSS) problem is to find a vertex …

The Directed Steiner Network (DSN) problem takes as input a directed graph G=(V, E) with
non-negative edge-weights and a set D⊆ V× V of k demand pairs. The aim is to compute the …

The DIRECTED STEINER NETWORK (DSN) problem takes as input a directed edge-
weighted graph G=(V, E) and a set D⊆ V× V of k demand pairs. The aim is to compute the …

The Directed Steiner Tree (DST) problem is a cornerstone problem in network design. We
focus on the generalization of the problem with higher connectivity requirements. The …

We study the parameterized complexity of the directed variant of the classical Steiner Tree
problem on various classes of directed sparse graphs. While the parameterized complexity …