A Linear-Time Approximation Algorithm for Rotation Distance

TL;DR

This paper introduces a linear-time approximation algorithm for rotation distance between rooted binary trees, providing a fast estimate within a factor of 2, addressing the computational challenge of exact calculation.

Contribution

The paper presents the first linear-time algorithm that approximates rotation distance within a provable factor of 2, improving efficiency over previous methods.

Findings

Algorithm runs in linear time

Approximation factor is guaranteed to be within 2

Effective for ordered rooted binary trees

Abstract

Rotation distance between rooted binary trees measures the number of simple operations it takes to transform one tree into another. There are no known polynomial-time algorithms for computing rotation distance. We give an efficient, linear-time approximation algorithm, which estimates the rotation distance, within a provable factor of 2, between ordered rooted binary trees. .