Shirou Maruyama

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A space-efficient approximation algorithm for the grammar-based compression problem, which requests for a given string to find a smallest context-free grammar deriving the string, is presented. For the input length n and an optimum CFG size g, the algorithm consumes only O(g log g) space and O(n log * n) time to achieve O((log * n) log n) approximation(More)
We consider the problem of restructuring compressed texts without explicit decompression. We present algorithms which allow conversions from compressed representations of a string T produced by any grammar-based compression algorithm, to representations produced by several specific compression algorithms including LZ77, LZ78, run length encoding, and some(More)
Practical data structures for the edit-sensitive parsing (ESP) are proposed. Given a string $S$ , its ESP tree is equivalent to a context-free grammar $G$ generating just $S$ , which is represented by a DAG. Using the succinct data structures for trees and permutations, $G$ is decomposed to two LOUDS bit strings and single array in $(1+\epsilon)n\log(More)
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