A transversal of a hypergraph is a set of vertices meeting all the hyperedges. A k-fold transversal of a hypergraph is a set of vertices such that every hyperedge has at least k elements of. In this paper, we prove that a k-fold transversal of a balanced hypergraph can be expressed as a union of k pairwise disjoint transversals and such partition can be obtained in polynomial time. We give an N...

Inclusion/exclusion and measure and conquer are two of the most important recent new developments in the field of exact exponential time algorithms. Algorithms that combine both techniques have been found very recently, but thus far always use exponential space. In this paper, we try to obtain fast exponential time algorithms for graph domination problems using only polynomial space. Using a no...

The structure generating function of a language enumerates the number of distinct words contained in the language with respect to their length. Given any unambiguous tuple grammar, a method is described which yields a system of equations, whose unique solution is the structure generating function. The entropy (channel capacity) is an important information theoretic quantity associated with a la...

A {em Roman dominating function} on a graph $G$ is a function $f:V(G)rightarrow {0,1,2}$ satisfying the condition that every vertex $u$ for which $f(u)=0$ is adjacent to at least one vertex $v$ for which $f(v)=2$. A {em total Roman dominating function} is a Roman dominating function with the additional property that the subgraph of $G$ induced by the set of all vertices of positive weight has n...

In this article we focus on the parameterized complexity of the Multidimensional Binary Vector Assignment problem (called BMVA). An input of this problem is defined by m disjoint sets V , V , . . . , V , each composed of n binary vectors of size p. An output is a set of n disjoint m-tuples of vectors, where each m-tuple is obtained by picking one vector from each set V . To each m-tuple we asso...

NP-complete problems cannot have efficient algorithms unless P = NP. Due to their importance in practice, however, it is useful to improve the known exponential-time algorithms for NP-complete problems. We survey some of the recent results on such improved exponential-time algorithms for the NP-complete problems satisfiability, graph colorability, and the domatic number problem. The determinist...

A k-tuple coloring of a graph G assigns a set of k colors to each vertex of G so that if two vertices are adjacent, the corresponding sets of colors are disjoint. The k-tuple chromatic number of G is the smallest t so that there is such a k-tuple coloring of G using t colors in all. The Kneser graph K(m,n) has as vertices all n-element subsets of the set {1,2, . . . ,m} and an edge between two ...