2020/04/01 by Claude, Francisco, Navarro, Gonzalo, Pacheco, Alejandro · 1 citation
#Data Structures and Algorithms (cs.DS) #FOS: Computer and information sciences
paper · doi:10.48550/arxiv.2004.01032
Let a text T[1..n] be the only string generated by a context-free grammar with g (terminal and nonterminal) symbols, and of size G (measured as the sum of the lengths of the right-hand sides of the rules). Such a grammar, called a grammar-compressed representation of T, can be encoded using essentially G\lg g bits. We introduce the first grammar-compressed index that uses O(G\lg n) bits and can find the occ occurrences of patterns P[1..m] in time O((m2+occ)\lg G). We implement the index and demonstrate its practicality in comparison with the state of the art, on highly repetitive text collections.