Given a set S of elements in a directed network that are initially faulty, an element becomes (functionally) faulty if all its in-neighbors or all its outneighbors are (functional...
In this paper we initiate the study of the AND-OR directed feedback vertex set problem from the viewpoint of approximation algorithms. This AND-OR feedback vertex set problem is m...
Kamal Jain, Mohammad Taghi Hajiaghayi, Kunal Talwa...
A hitting set for a collection of sets is a set that has a nonempty intersection with each set in the collection; the hitting set problem is to find a hitting set of minimum card...
Karthekeyan Chandrasekaran, Richard Karp, Erick Mo...
A tournament T = (V, A) is a directed graph in which there is exactly one arc between every pair of distinct vertices. Given a digraph on n vertices and an integer parameter k, th...
In this paper we initiate a systematic study of the Reduced Degree Spanning Tree problem, where given a digraph D and a nonnegative integer k, the goal is to construct a spanning o...
Daniel Lokshtanov, Venkatesh Raman, Saket Saurabh,...