Traversing Grammar-Compressed Trees with Constant Delay

TL;DR

This paper introduces a data structure for grammar-compressed trees that allows constant-time traversal and subtree equality checks, significantly improving efficiency for large tree structures.

Contribution

It presents a novel grammar-compressed tree representation enabling constant delay traversal and subtree equality testing, advancing tree compression and querying techniques.

Findings

Traversal steps take constant time

Subtree equality checks are performed in constant time

The data structure maintains linear space overhead

Abstract

A grammar-compressed ranked tree is represented with a linear space overhead so that a single traversal step, i.e., the move to the parent or the i-th child, can be carried out in constant time. Moreover, we extend our data structure such that equality of subtrees can be checked in constant time.