# Space-efficient merging of succinct de Bruijn graphs

## TL;DR

This paper introduces a space-efficient algorithm for merging succinct de Bruijn graphs, capable of computing variable order representations within the same asymptotic bounds, improving space usage over existing methods.

## Contribution

It presents a novel merging algorithm based on lightweight BWT merging that reduces working space and computes variable order representations efficiently.

## Key findings

- Uses less than half the working space of existing tools.
- Maintains the same asymptotic time complexity as state-of-the-art methods.
- Can compute variable order succinct representations within the same bounds.

## Abstract

We propose a new algorithm for merging succinct representations of de Bruijn graphs introduced in [Bowe et al. WABI 2012]. Our algorithm is based on the lightweight BWT merging approach by Holt and McMillan [Bionformatics 2014, ACM-BCB 2014]. Our algorithm has the same asymptotic cost of the state of the art tool for the same problem presented by Muggli et al. [bioRxiv 2017, Bioinformatics 2019], but it uses less than half of its working space. A novel important feature of our algorithm, not found in any of the existing tools, is that it can compute the Variable Order succinct representation of the union graph within the same asymptotic time/space bounds.