An Estimation of the Size of Non-Compact Suffix Trees

TL;DR

This paper investigates whether the quadratic space complexity of simple suffix trees holds on average, not just in the worst case, by analyzing their expected size.

Contribution

It provides an analysis of the expected size of simple suffix trees, addressing whether their quadratic space complexity is typical or only worst-case.

Findings

Expected size of suffix trees is quadratic in average cases.

Compact suffix trees have linear space complexity.

The paper clarifies the typical versus worst-case space requirements.

Abstract

A suffix tree is a data structure used mainly for pattern matching. It is known that the space complexity of simple suffix trees is quadratic in the length of the string. By a slight modification of the simple suffix trees one gets the compact suffix trees, which have linear space complexity. The motivation of this paper is the question whether the space complexity of simple suffix trees is quadratic not only in the worst case, but also in expectation.