MFCS
2001
Springer
13 years 8 months ago
2001
Springer
Abstract. We prove that the class of context-free languages with polynomially bounded ambiguity (PCFL) is the closure of the class of unambiguous languages (UCFL) under projections...
MFCS
2001
Springer
13 years 8 months ago
2001
Springer
We show that it is not possible to approximate the minimum Steiner tree problem within 1 + 1 162 unless RP = NP. The currently best known lower bound is 1 + 1 400. The reduction i...
MFCS
2001
Springer
13 years 8 months ago
2001
Springer
We describe a class of simple transitive semiautomata that exhibit full exponential blow-up during deterministic simulation. For arbitrary semiautomata we show that it is PSPACE-c...
MFCS
2001
Springer
13 years 8 months ago
2001
Springer
MFCS
2001
Springer
13 years 8 months ago
2001
Springer
We describe an explicit simulation of 2-way nondeterministic automata by 1-way alternating automata with quadratic blow-up. We first describe the construction for automata on fin...
MFCS
2001
Springer
13 years 8 months ago
2001
Springer
This paper shows that the traces of rational graphs coincide with the context-sensitive languages.
MFCS
2001
Springer
13 years 8 months ago
2001
Springer
MFCS
2001
Springer
13 years 8 months ago
2001
Springer
In the traveling repairman problem (Trp), a tour must be found through every one of a set of points (cities) in some metric space such that the weighted sum of completion times of ...
MFCS
2001
Springer
13 years 8 months ago
2001
Springer
MFCS
2001
Springer
13 years 8 months ago
2001
Springer
Combinatorial games lead to several interesting, clean problems in algorithms and complexity theory, many of which remain open. The purpose of this paper is to provide an overview...