Juraj Hromkovic

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Let's read! We will often find out this sentence everywhere. When still being a kid, mom used to order us to always read, so did the teacher. Some books are fully read in a week and we need the obligation to support reading. What about now? Do you still love reading? Is reading only for you who have obligation? Absolutely not! We here offer you a new book(More)
It is proved that every regular expression of size n can be converted into an equivalent nondeterministic nite automaton (NFA) of size O(n(log n) 2) in polynomial time. The best previous conversions result in NFAs of worst case size (n 2). Moreover, the nonexistence of any linear conversion is proved: we give a language Ln described by a regular expression(More)
While deterministic finite automata seem to be well understood, surprisingly many important problems concerning nondeterministic finite automata (nfa’s) remain open. One such problem area is the study of different measures of nondeterminism in finite automata and the estimation of the sizes of minimal nondeterministic finite automata. In this paper the(More)
The advice complexity of an online problem describes the additional information both necessary and sufficient for online algorithms to compute solutions of a certain quality. In this model, an oracle inspects the input before it is processed by an online algorithm. Depending on the input string, the oracle prepares an advice bit string that is accessed(More)
We present a new technique to differentiate deterministic from nondeterministic communication complexity. As a consequence we give almost tight lower bounds for the nondeterministic communication complexity with a restricted number of advice bits (i. e., nondeterministic guesses). In particular, for any function t : N + N (with t(k)< k/2) we construct a(More)
We consider the job shop scheduling problem unit−Jm, where each job is processed once on each of m given machines. Every job consists of a permutation of tasks for all machines. The execution of any task on its corresponding machine takes exactly one time unit. The objective is to minimize the overall completion time, called makespan. The contribution of(More)
We consider the following reoptimization scenario: Given an instance of an optimization problem together with an optimal solution, we want to find a high-quality solution for a locally modified instance. The naturally arising question is whether the knowledge of an optimal solution to the unaltered instance can help in solving the locally modified instance.(More)