# QUBOs for Sorting Lists and Building Trees

arXiv: https://arxiv.org/abs/2203.08815 · HTML: https://mlsanity.com/paper/2203.08815/

## Key facts

- No citing papers in the map yet (data through 14 Oct 2026).
- Builds on 2 of its 18 references that are in the map.
- First posted on arXiv 15 Mar 2022.

## Builds on (most cited first, 2 of 2)

- [Ising formulations of many NP problems](https://mlsanity.com/paper/1302.5843/) (2013)
- [QUBO Formulations for Training Machine Learning Models](https://mlsanity.com/paper/2008.02369/) (2020)

## Abstract (arXiv)

We show that the fundamental tasks of sorting lists and building search trees or heaps can be modeled as quadratic unconstrained binary optimization problems (QUBOs). The idea is to understand these tasks as permutation problems and to devise QUBOs whose solutions represent appropriate permutation matrices. We discuss how to construct such QUBOs and how to solve them using Hopfield nets or adiabatic) quantum computing. In short, we show that neurocomputing methods or quantum computers can solve problems usually associated with abstract data structures.