Daniel Valenzuela

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We give new space/time tradeoffs for compressed indexes that answer document retrieval queries on general sequences. On a collection of D documents of total length n, current approaches require at least |CSA| + O(n lg D lg lg D) or 2|CSA| + o(n) bits of space, where CSA is a full-text index. Using monotone minimum perfect hash functions, we give new(More)
Given a collection of documents and a query pattern, <i>document retrieval</i> is the problem of obtaining documents that are relevant to the query. The collection is available beforehand so that a data structure, called an index, can be built on it to speed up queries. While initially restricted to natural language text collections, document retrieval(More)
In the classical interval scheduling type of problems, a set of n jobs, characterized by their start and end time, need to be executed by a set of machines, under various constraints. In this paper we study a new variant in which the jobs need to be assigned to at most k identical machines, such that the minimum number of machines that are busy at the same(More)