News

PACE 2025: Begin of the Evaluation Phase

Dear all, the evaluation phase has just started. Find a list of all participating solvers here. Please contact us if you spot errors.

PACE 2025: Submission Deadline is Approching (and a small change to the docker environment)

Dear all, the solver submission deadline is approaching. We thank all participants for their participation! We fixed a small issue within the provided docker environment: the evaluation script handed the instance to the solver via a path descriptor as an argument, not via stdin. We have changed the evaluation script such that the input is provided via stdin, being consistent with optil.io and the description on this webpage. If you have modified your code to take the instance path as an argument, feel free to change it or leave it as it is; just make sure to include a short notice in your installation guide if your solver expects the input not to be provided via stdin. Sorry for the inconvenience!

PACE 2025: Docker Evaluation Environment

We provide a docker stack on Github containing the evaluation environment as it will be used for the final evaluation. For further information click here.

PACE 2025: Submission Guideline

We have added information on the submission guideline. Find more information here. Furthermore we have slightly updated the recently announced scoring system for the heuristic tracks in order to compute a fairer score for instances where the optimal solution size is significantly smaller than the number of vertices. Find more information here.

PACE 2025: Scoring system

We have added information on this years scoring system. Find more information here.

PACE 2025: Optil is now live!

The preliminary leaderboard on optil is now live. Find more information here and directly on optil.

PACE 2025: Timeline Update and FAQ

We have updated the timeline. The deadline for the solvers is Friday, 13.06.2025, 23:59 AOE. Recall this years procedure to ensure the correctness of exact solvers. We have also added a small FAQ. We expect the preliminary leaderboard on optil to go live within the next few days. Happy Coding!

PACE 2025: Public Instances are Available on Github

We are happy to announce that the public instances are (finally) on GitHub. Please note that we had to compress the instances for the heuristic tracks in order to stay within the file size limit. Finally, we would like to give a short update on the current status of optil: the team behind optil is still working on setting everything up. We expect the preliminary leaderboard to go live in the near future.

PACE 2025: Update on the Current Status

We have prepared a preliminary set of 50 instances for the exact track of the Dominating Set Challenge. Find them on GitHub. For both problems, we plan to add a full set of 100 instances for the exact track as well as a full set of 100 instances for the heuristic track by the end of february.

PACE 2025: Verifiers and small test sets are available!

Verifiers and small test sets are now available! Find them on Github; for Dominating Set click here and for Hitting Set click here.

PACE 2025: Correctness of the exact solvers

We announce new rules for ensuring the correctness of the exact solvers. Find the details here.

PACE 2025: Call for Participation

We are pleased to announce the 10th iteration of PACE, the Parameterized Algorithms and Computational Experiments Challenge! The challenges for this year are Dominating Set and Hitting Set. Find the details here.

PACE 2024: Results are out!

We are happy to announce the results of PACE 2024. Congratulations to the winners and all the participants! You can now find all instances and their optimal solutions on the contest page and the slides from the award ceremony here.

PACE 2024: Call for Participation

We are pleased to announce the ninth iteration of PACE, the Parameterized Algorithms and Computational Experiments Challenge! The challenge for this year is One-Sided Crossing Minimization. Find the details here.

PACE 2023: Results are out!

We are happy to announce the results of PACE 2023. Congratulations to the winners and all the participants.

PACE 2022: results are out!

We are happy to announce the results of PACE 2022. Congratulations to the winners and all the participants.

PACE 2022: Easychair Platform Now Open!

The easychair platform to register your solver and later to submit the solver description is now open! See also the submission requirements of PACE 2022.

PACE 2022: Public Instances are Available!

We have published public instances! Here are public instances for exact track and heuristic track.

PACE 2022: Call for Participation

We are pleased to announce the seventh iteration of PACE, the Parameterized Algorithms and Computational Experiments Challenge! The challenge for this year is Directed Feedback Vertex Set. Find the details here.

PACE 2021: results are out!

We are happy to announce the results of PACE 2021. Congratulations to the winners and all the participants.

PACE 2021: Public Instances are Available!

We have published public instances! Here are public instances for exact track and kernelization track and heuristic track.

PACE 2021: Call for Participation

We are pleased to announce the sixth iteration of PACE, the Parameterized Algorithms and Computational Experiments Challenge! The challenge for this year is Cluster Editing. Find the details here.

PACE 2020: Repository with all PACE 2020 instances

We created a repository which contains all our (public and private) instances. Enjoy! Each instance file has comment lines with instance type (e.g. biology, social networks), origin and description. We hope that the repo will be useful for future PACE organizers and for researchers working in algorithm engineering.

PACE 2020: results are out!

We are happy to announce the results of PACE 2020. Congratulations to the winners and all the participants. You are great!

PACE 2020: at most three submissions per team

We decided that: 

1. we allow at most three submissions per team per track
2. in each track we rank teams (and not submissions) according to the best solver of a team. 
3. all the rules for submissions apply, in particular each submission should have its public repository and description.

PACE 2020: both tracks are running at optil.io

We are happy to announce that you can now submit your solutions to optil.io. Let us recall that the final deadline for submission is June, 1. Until the submission deadline, you will be able to test your solution on public instances and see unofficial rankings. Please note that the ranking published at optil.io is only auxiliary. In particular:

Challenge Poster

Felix Reidl designed a poster for us! See / download the poster below.

PACE 2020: Detailed rules and public instances

Detailed rules of the two tracks of PACE 2020 and public instances are now online, enjoy! See the PACE 2020 challenge description and general information.

PACE 2020 Call for Participation

We are happy to announce the fifth iteration of PACE, the Parameterized Algorithms and Computational Experiments Challenge. The goal of PACE is to investigate the applicability of algorithmic ideas studied and developed in the subfields of multivariate, fine-grained, parameterized, or fixed-parameter tractable algorithms.

PACE 2019 ceremony at IPEC

Private Instances of the PACE2019 Challenge

We published the private and public instances for both tracks on Zenodo. For details we refer to: 1) Instances from the Vertex Cover Track 2) Instances from both Hypertree Decomposition Tracks

Results of the 4th PACE Challenge

We published preliminary results of the PACE2019 challenge. The final results and winners will be announced during the award ceremony at IPEC2019 in Munich.

Deadline extension (solver description). New. June, 3rd (AOE)

Due to problems with the submission system easychair, we extend the deadline until Monday June 3rd, 2019 (AOE). We’ve been informed on May 30th that easychair is experiencing network problems which however should have already beenresolved on May 31st (see below). Nonetheless, due to several requests still reporting problems, we decided to extend the deadline further.

How to interpret Optil's status messages

Jan from optil.io informed us that their system sometimes gets stuck when a submission is killed due to reaching the time limit.

Optil issues resolved

The issue should be resolved.

Optil: Technical issues with submission system

We are currently experiencing some issues with the optil system. The problem was first reported yesterday. According to optil, they ran a system update. We are in contact with the optil team.  Unfortunately, there is a public holiday on May 1st and May 3rd in Poland, so we might get answers not before Monday. 

PACE 2019 Call for Participation

We are happy to announce the fourth iteration of PACE, the Parameterized Algorithms and Computational Experiments Challenge. The goal of PACE is to investigate the applicability of algorithmic ideas studied and developed in the subfields of multivariate, fine-grained, parameterized, or fixed-parameter tractable algorithms. This year, the challenge consists of two separate tracks.

PACE 2018 ceremony at IPEC

The award ceremony took place in Helsinki. The slides are available and show the results.

PACE 2018 now on OPTIL.io

We are happy to announce that PACE 2018 will cooperate again with OPTIL.io to handle the submission process and the evaluation of the submissions. OPTIL.io is a website for organizing programming challenges on optimization problems, created and maintained by the Institute of Computing Science of Poznan University of Technology.

PACE 2018 Call for Participation

The PACE 2018 challenge has started! This year there is only one problem, Steiner Tree, and three tracks: two for exact algorithms and one for heuristics. To register your team now and find out all the details of the challenge, visit the challenge page.

Extension of submission deadline

Due to numerous requests, we decided to allow submissions for Track A and Track B until May 25. Thanks to the cooperation with OPTIL.io, we can still send out the notification on June 1.

PACE is cooperating with OPTIL.io

March 1 has passed which means that submission is possible from now until May 1 for both tracks of PACE 2017.

PACE 2017 Announcement

We are happy to announce the second iteration of PACE, the Parameterized Algorithms and Computational Experiments Challenge. The goal of PACE is to investigate the applicability of algorithmic ideas studied and developed in the subfields of multivariate, fine-grained, parameterized, or fixed-parameter tractable algorithms. The challenge consists of two separate tracks.

Results of the First PACE Challenge

The winners of the 1st PACE competition were presented at ALGO 2016 in Aarhus. For those that couldn’t make it to Aarhus: here are the results. We would like to thank all participants for making this 1st edition of PACE an enjoyable and successful one.

Challenge Prizes and Travel Awards

Thanks to the generous support of the NWO Gravitation project NETWORKS, we can announce the following awards for the first PACE challenge.

The First PACE Challenge

The goal of the Parameterized Algorithms and Computational Experiments Challenge (PACE) is to investigate the applicability of algorithmic ideas studied and developed in the subfields of multivariate, fine-grained, parameterized, or fixed-parameter tractable algorithms. In particular, it aims to