We study the fully compressed pattern matching problem (FCPM problem): Given T and P which are descriptions of text T and pattern P respectively, find the occurrences of P in T without decompressing T or P. This problem is rather challenging since patterns are also given in a compressed form. In this paper we present an FCPM algorithm for simple collage systems. Collage systems are a general framework representing various kinds of dictionary-based compressions in a uniform way, and simple collage systems are a subclass that includes LZW and LZ78 compressions. Collage systems are of the form (〈D, S〉, where D is a dictionary and S is a sequence of variables from D. Our FCPM algorithm performs in O(∥D∥ 2 + mn log|S|) time, where n = |T| = ∥D∥ + |S| and m = |P|. This is faster than the previous best result of O(m 2n 2) time.
|Number of pages||12|
|Journal||International Journal of Foundations of Computer Science|
|Publication status||Published - 2005 Dec|
- Collage systems
- Fully compressed pattern matching
- String processing
- Text compression