We present an exact algorithm that decides, for every fixed <i>r</i> â‰¥ 2 in time <i>O(m) + 2<sup>O(k2</sup>)</i> whether a given set of <i>m</i> clauses of size <i>r</i> admits a truth assignmentâ€¦ (More)

Given a digraph D, the Minimum Leaf Out-Branching problem (MinLOB) is the problem of finding in D an out-branching with the minimum possible number of leaves, i.e., vertices of out-degree 0. We proveâ€¦ (More)

The recently introduced graph parameter tree-cut width plays a similar role with respect to immersions as the graph parameter treewidth plays with respect to minors. In this paper we provide theâ€¦ (More)

Given a digraph D, the Minimum Leaf Out-Branching problem (MinLOB) is the problem of finding in D an out-branching with the minimum possible number of leaves, i.e., vertices of out-degree 0. We proveâ€¦ (More)

Fixed-parameter algorithms, approximation algorithms and moderately exponential algorithms are three major approaches to algorithm design. While each of them being very active in its own, there is anâ€¦ (More)

Local Search is one of the fundamental approaches to combinatorial optimization and it is used throughout AI. Several local search algorithms are based on searching the k-exchange neighborhood. Thisâ€¦ (More)

Results from inapproximability provide several sharp thresholds on the approximability of important optimization problems. We give several improved parameterized algorithms for solving constraintâ€¦ (More)