Computing q-gram Frequencies on Collage Systems

TL;DR

This paper introduces an efficient algorithm for computing all q-gram frequencies in strings represented by collage systems, a general framework for compressed text, with improved time complexity.

Contribution

It presents the first algorithm with a time complexity of O((q+h log n)n) for all q-gram frequency computation on collage system compressed strings.

Findings

Algorithm computes all q-gram frequencies efficiently.

Time complexity depends on string size, q, and collage system height.

Provides a practical method for analyzing compressed texts.

Abstract

Collage systems are a general framework for representing outputs of various text compression algorithms. We consider the all $q$-gram frequency problem on compressed string represented as a collage system, and present an $O((q+h\log n)n)$-time $O(qn)$-space algorithm for calculating the frequencies for all $q$-grams that occur in the string. Here, $n$ and $h$ are respectively the size and height of the collage system.