- Postdoctoral research associate working on modelling and optimisation with graphs, doing the bidding of Patrick Prosser in the Formal Analysis, Theory and Algorithms and Parallelism groups in the School of Computing Science at the University of Glasgow.
- Email: ciaran.mccreesh at glasgow.ac.uk .
- Office: F142 Lilybank Gardens. Enter through the Sir Alwyn Williams building (campus map D20), through the glass double doors, up one and a half a flight of stairs to the floor marked F, and along the corridor a bit.

- Slides from my FATA talk on computational experiments, sample size fifteen billion, and my two talks at KTH on modelling and optimisation with graphs, and whether hard graph problems are hard.
- I will co-chair the doctoral program at CP 2019.
- I was awarded the Association for Constraint Programming Doctoral Research Award for my PhD thesis.

- Solving (NP) hard problems in practice, particularly combinatorial optimisation and graph theory problems.
- Understanding computational complexity starting from science and experiments, rather than axioms: what makes hard problems really hard in practice, and how does this help us design better algorithms?
- Empirical algorithmics and algorithm engineering.
- Constraint programming and old-school, uncool artificial intelligence.
- Parallel search for branch and bound algorithms, and parallelism for intelligent backtracking search.
- Being an existential threat to humanity.

- My GitHub profile contains code, experimental scripts, etc to reproduce experiments in my publications.
- The Glasgow Subgraph Solver is based upon a series of papers by (subsets of) myself, Patrick Prosser, and James Trimble. This is the version of the code you should use if you're just interested in having a good solver, rather than reproducing the results in a particular paper.
- This repository contains a presentation along with a Beamer theme which more or less complies with University regulations. You are welcome to steal this and abuse it for your own nefarious purposes. Here are the slides for the talk itself.
- This repository directory contains a poster using the TikZPoster package for LaTeX which similarly approximately follows regulations. Again, help yourself
- Parasols contains parallel subgraph algorithms from my PhD thesis.

- Ciaran McCreesh, William Pettersson and Patrick Prosser:
**Understanding the Empirical Hardness of Random Optimisation Problem.**

To appear at CP 2019.

[author-final PDF] - Blair Archibald, Fraser Dunlop, Ruth Hoffmann, Ciaran McCreesh, Patrick Prosser and James
Trimble:
**Sequential and Parallel Solution-Biased Search for Subgraph Algorithms.**

CPAIOR 2019: 20-38.

[author-final PDF, source code] - Ian P. Gent, Ian Miguel, Peter Nightingale, Ciaran McCreesh, Patrick Prosser, Neil C. A. Moore, Chris
Unsworth:
**A review of literature on parallel constraint solving.**

TPLP 18(5-6): 725-758 (2018).

[DOI, author-final PDF] - José Cano, David Robert White, Alejandro Bordallo, Ciaran McCreesh, Anna Lito Michala, Jeremy Singer,
Vijay Nagarajan:
**Solving the task variant allocation problem in distributed robotics.**

Auton. Robots 42(7): 1477-1495 (2018).

[DOI (open access)] - Ciaran McCreesh, Patrick Prosser, Christine Solnon and James Trimble:
**When Subgraph Isomorphism is Really Hard, and Why This Matters for Graph Databases.**

Journal of Artificial Intelligence Research (JAIR) 61: 723-759 (2018).

[DOI (open access), Author-final PDF] - Ruth Hoffmann, Ciaran McCreesh, Samba Ndojh Ndiaye, Patrick Prosser, Craig Reilly, Christine Solnon, and James Trimble:
**Observations from Parallelising Three Maximum Common (Connected) Subgraph Algorithms.**

CPAIOR 2018: 298-315.

[author-final PDF, source code] - Blair Archibald, Patrick Maier, Ciaran McCreesh, Robert Stewart and Phil Trinder:
**Replicable parallel branch and bound search.**

Journal of Parallel and Distributed Computing, Volume 113, 92-114 (2018)

[DOI (open access)] - Ciaran McCreesh:
**Solving Hard Subgraph Problems in Parallel.**

PhD thesis. University of Glasgow, 2017.

[PDF] - Ciaran McCreesh, Patrick Prosser, Kyle Simpson and James Trimble:
**On Maximum Weight Clique Algorithms, and How They Are Evaluated.**

CP 2017: 206-225.

[DOI, author-final PDF, maximum weight clique benchmark instances] - Ciaran McCreesh, Patrick Prosser and James Trimble:
**A Partitioning Algorithm for Maximum Common Subgraph Problems.**

IJCAI 2017: 712-719.

[DOI, author-final PDF, source code] - Ruth Hoffmann, Ciaran McCreesh and Craig Reilly:
**Between Subgraph Isomorphism and Maximum Common Subgraph.**

AAAI 2017: 3907-3914.

[abstract and PDF, author-final PDF, Source code] - Ciaran McCreesh, Samba Ndojh Ndiaye, Patrick Prosser and Christine Solnon:
**Clique and Constraint Models for Maximum Common (Connected) Subgraph Problems.**

CP 2016: 350-368.

[DOI, author-final PDF, Source code] - Ciaran McCreesh, Patrick Prosser and James Trimble:
**Morphing between Stable Matching Problems**

CP 2016: 832-840

[DOI, author-final PDF] - Ciaran McCreesh, Patrick Prosser and James Trimble:
**Heuristics and Really Hard Instances for Subgraph Isomorphism Problems.**

IJCAI 2016: 631-638.

[abstract and PDF, author-final PDF, Conference Talk (10 minutes), A0 Poster, Source code] - Ciaran McCreesh and Patrick Prosser:
**Finding Maximum k-Cliques Faster Using Lazy Global Domination.**

SoCS 2016: 72-80.

[abstract and PDF, author-final PDF, Older preprint on arXiv, Conference Talk, Source code] - Jose Cano Reyes, David White, Alejandro Bordallo, Ciaran McCreesh, Patrick Prosser, Jeremy Singer and
Vijay Nagarajan:
**Task Variant Allocation in Distributed Robotics.**

Robotics Science and Systems 2016.

[PDF, author-final PDF] - Lars Kotthoff, Ciaran McCreesh and Christine Solnon:
**Portfolios of Subgraph Isomorphism Algorithms.**

LION 2016: 107-122.

[DOI, author-final PDF, Source code] - Ciaran McCreesh, Patrick Prosser:
**A Parallel, Backjumping Subgraph Isomorphism Algorithm using Supplemental Graphs.**

CP 2015: 295-312.

[DOI, author-final PDF, code, datasets, experimental scripts, VM for recomputation, conference presentation] - Craig Macdonald, Ciaran McCreesh, Alice Miller and Patrick Prosser:
**Constructing Sailing Match Race Schedules: Round-Robin Pairing Lists.**

CP 2015: 671-686

[DOI, author-final PDF, industry poster] - Ciaran McCreesh, Patrick Prosser:
**The Shape of the Search Tree for the Maximum Clique Problem, and the Implications for Parallel Branch and Bound.**

ACM Transactions on Parallel Computing Volume 2 Issue 1 (2015).

[DOI, ACM Author-izer PDF (if this link doesn't get you the paper for free, try prepending`www.`

to this page's URL, or email me), Older preprint on arXiv]. - Ciaran McCreesh, Patrick Prosser:
**A Parallel Branch and Bound Algorithm for the Maximum Labelled Clique Problem.**

Optimization Letters (2014)

[DOI (open access)]. - Ciaran McCreesh, Patrick Prosser:
**Reducing the Branching in a Branch and Bound Algorithm for the Maximum Clique Problem.**

CP 2014: 549-563

[DOI, author-final PDF] - Ciaran McCreesh, Patrick Prosser:
**An Exact Branch and Bound Algorithm with Symmetry Breaking for the Maximum Balanced Induced Biclique Problem.**

CPAIOR 2014: 226-234

[DOI, author-final PDF] - Ciaran McCreesh, Patrick Prosser:
**Multi-Threading a State-of-the-Art Maximum Clique Algorithm.**

Algorithms 6(4): 618-635 (2013)

[DOI (open access)]

Here's a three minute video of what I was originally planning to do for my thesis, for a non-technical audience: