We study a variation of the vertex cover problem where it is required that the graph induced by the vertex cover is connected. We prove that this problem is polynomial in chordal g...
Abstract. The maximum intersection problem for a matroid and a greedoid, given by polynomial-time oracles, is shown NP-hard by expressing the satisfiability of boolean formulas in...
We show that some natural refinements of the Straubing and Brzozowski hierarchies correspond (via the so called leaf-languages) step by step to similar refinements of the polynom...
We show1 that non-deterministic time NTIME(n) is not contained in deterministic time n 2and polylogarithmic space, for any > 0. This implies that (infinitely often) satisfiabi...
Two new algorithms for performing arithmetic coding without employing multiplication are presented. The first algorithm, suitable for an alphabet of arbitrary size, reduces the wo...