Roberto Radicioni

Literal Shuffle of Compressed Words

Straight-Line Programs (SLP) are widely used compressed representations of words. In this work we study the rational transformations and the literal shuffle of words compressed via SLP, proving that the first preserves the compression rate, while the second does not. As a consequence, we prove a tight bound for the descriptional complexity of 2D texts compressed via SLP. Finally, we observe that the Pattern Matching Problem for texts expressed by the literal shuffle of compressed words is NP-complete. However, we present a parameter-tractable algorithm for this problem, working in polynomial time whenever the length of the pattern is polynomially related to that of the text.

A CAT algorithm for the exhaustive generation of ice piles

We present a CAT (constant amortized time) algorithm for generating those partitions of n that are in the ice pile model

The number of convex permutominoes

\mbox{IPM}_k

The Inclusion Problem of Context-Free Languages: Some Tractable Cases

( n ), a generalization of the sand pile model

THE INCLUSION PROBLEM OF CONTEXT-FREE LANGUAGES: SOME TRACTABLE CASES

\mbox{SPM}

Average value and variance of pattern statistics in rational models

( n ). More precisely, for any fixed integer k , we show that the negative lexicographic ordering naturally identifies a tree structure on the lattice

On computing the coefficients of bivariate holonomic formal series

\mbox{IPM}_k

Probabilistic models for pattern statistics

( n ): this lets us design an algorithm which generates all the ice piles of

APPROXIMATING THE MEAN SPEEDUP IN TRACE MONOIDS

\mbox{IPM}_k

Approximability and non-approximability results in computing the mean speedup of trace monoids

( n ) in amortized time O (1) and in space O (