23rd Max Planck Advanced Course on the Foundations of Computer Science

23rd Max Planck Advanced Course on the Foundations of Computer Science

21 - 25 August 2023, Saarbrücken, Germany

Algorithmic Foundations of Data Analysis

Group Picture

We thank all participants for this successful event!

The goal of this year's ADFOCS is to educate people with a TCS background on topics such as clustering, metric embeddings, and beyond worst-case analysis; thereby also promoting these areas and their importance.

This summer school's scope is international, and its goal is to bring together leading researchers with international participants of graduate level and above.

No prior knowledge is necessary to attend this course.

The registration is now open (see the Registration tab) and we have the preliminary schedule (see the Program tab).

Vincent Cohen-Addad

Vincent Cohen-Addad

Google Research,

Graph Clustering: Approximation and Practical Algorithms

Yury Makarychev

Yury Makarychev

Toyota Technological Institute at Chicago (TTIC)

Beyond Worst-Case Analysis and Fairness

Ola Svensson

Ola Svensson

École Polytechnique Fédérale de Lausanne (EPFL)

Explainability and Data-Driven Algorithm Design

ADFOCS is organized by Evangelos Kipouridis, Danupon Nanongkai, Joachim Spoerhase and Philip Wellnitz as part of the activities of the Algorithms and Complexity Group and the International Max Planck Research School of the Max Planck Institute for Informatics.


Please do not hesitate to contact us for any questions via email to

This year's ADFOCS features three lecturers, each of which will give three lectures and two exercise sessions. They will be distributed to eight blocks of about four hours. A typical morning or afternoon block will start with 1 1/2 hours of lecture, followed by 2 hours of exercises (in small groups without the lecturers). During the exercise periods, the respective lecturer will be around, as well as some drinks.


August 21
August 22
August 23
August 24
August 25
8.00-8.55 Registration
(Campus E1 4, ground floor)
9.00 Lecture
Ola Svensson
Vincent Cohen-Addad
Ola Svensson
Yury Makarychev
Yury Makarychev
10.45 Coffee Break Coffee Break Coffee Break Coffee Break Coffee Break
11.15 Exercises
Ola Svensson
Vincent Cohen-Addad
Talks by
MPII members
Vincent Cohen-Addad
Yury Makarychev
13.00 Lunch Lunch Lunch Lunch Lunch
14.30 Lecture
Vincent Cohen-Addad
Ola Svensson
Adventure park
Yury Makarychev
16.15 Coffee Break Coffee Break Coffee Break
16.45-18.30 Exercises
Vincent Cohen-Addad
Ola Svensson
Yury Makarychev


Here you can find the daily menu of our restaurant (Mensa). Using your coupons, you can get anything, except for the options at Mensa cafe. Note: In order to switch to English, you can select a date, and then click on the gear next to date. In the box that appears, at the bottom there is a dropdown for language with the word "sprache". Choose English.

Lecture halls:

All lectures, as well as the talks by MPII members, are happening on lecture hall HS003, building E 1 3.
For the exercise sessions you can go to any of the rooms R019/R021/R023/R024, building E 1 4.

Talks by members of MPI-INF:

On Wednesday morning, members and guests of the Algorithms and Complexity Group (D1) at MPI-INF will introduce the group by presenting their own work.


On Wednesday afternoon, there are no lectures. Instead, we offer an excursion to the Adventure Park Saar.
Participants should print, fill, and bring the participation form with them.

The registration fee is EUR 130 for early registration (deadline July 31st, 2023) and EUR 180 for late registration (August 1st, 2023).
The on-site registration (only early in the morning of 21st August, 2023, and not recommended) costs EUR 200.
This fee covers course material, lunches, and the excursion; it does not cover hotel accommodation.
We will provide some grants for graduate students and young researchers.

If you are a student (including PhD student) please register here: student registration
Otherwise please register here: regular registration

We strongly recommend to use the bank transfer option when registering.

Note: It may take some time for the Payment Status to change from "Pending", while we process and confirm your payment.

Preparation for "Graph Clustering: Approximation and Practical Algorithms"

Two algorithms for Correlation Clustering, namely the 3-approximation and the 5/2-approximation, from this paper. Mainly Sections 6 and 7.

If you prefer videos over papers, you can check these two videos about the 3-approximation and the 5/2-approximation algorithms.

Ola Svensson

Vincent Cohen-Addad

  • Hierarchical Clustering papers (in theory): 1 and 2
  • Hierarchical Clustering papers (in practice): 1, 2 and 3
  • Exercises and solutions

Yury Makarychev

Talks by members of MPI-INF:

On Wednesday morning, members and guests of the Algorithms and Complexity Group (D1) at MPI-INF introduced the group by presenting their own work.

We will offer a limited number of travel grants for graduate students and young researchers.


If you wish to apply for a grant, please send an email with a brief CV (name, affiliation, complete address, education, publications, nationality, etc.);
Please have your supervisor at your institute send an email with a brief letter of recommendation, certifying in particular your relation with the topics in ADFOCS, before the deadline.

Note that the travel grant is meant to roughly cover your local expenses (hotel/youth hostel, registration); it will not be sufficient to cover flight costs!

Please send both emails to and indicate as subject "ADFOCS grant application". You will receive a confirmation of receipt of your application.


June 30, 2023, 24:00 Central European Summer Time
(By the deadline, we must receive both the CV and the letter of recommendation)


by July 10, 2023

The participants are responsible for their accommodation. In Saarbrücken per-night prices including taxes and breakfast typically range from EURO 50 (youth hostel) to about EURO 105 (hotel, single room).

We have reserved a certain number of rooms in the following hotels. When booking a room, please refer to "ADFOCS23" since we have negotiated special rates for you.

Further options (without reserved contingents) include:

You can use this link to get route recommendations that are more accurate than Google Maps. You can also find an app with the same name to help you.

We highly recommend purchasing a Deutschlandticket. It costs EURO 49/month and gives access to buses, the tramway, and most trains. Note: The Deutschlandticket is only available by subscription. Make sure to cancel it early in advance, so that you only pay for August.

If you don't have a Deutschlandticket then:

  • The fare for one trip Frankfurt-Saarbrücken is roughly EURO 42. If you are a group of people, you may want to check the Quer-durchs-Land-Ticket.
  • On Monday you will be provided with a badge that gives you access to buses and Saarbahn (tramway) for the whole week. Before getting your badge, you can buy one-way tickets (roughly EURO 3), and daily tickets (EURO 5.20). Tickets can be bought from the bus driver on board the bus. At the Saarbahn, single tickets can be bought from ticket vending machines at Saarbahn stations or on board the trains.

Traveling to Saarbrücken

You will probably try to reach Saarbrücken by train. If you have a flight to Frankfurt, this is extremely easy. There is a train station right in the terminal building. Trains run frequently. You have to buy a ticket before you board the train, and there you can also ask which trains to take.

If you arrive at some other airport, things are not that simple, but there are still train connections.

From Saarbrücken main train station ("Saarbrücken Hauptbahnhof") to your hotel

From the train station to your hotel you can use public transport: Buses and a tramway that is called "Saarbahn".

  • The Hotel B&B Saarbrücken is located directly at the main train station.
  • For Hotel Madeleine, you take the tramway S1 with destination "Sarreguemines", "Brebach", or "Kleinblittersdorf" and get off at the stop "Johanneskirche" (two stops). You can also walk (15 minutes).
  • For the Youth Hostel, you take bus 124 with destination "Universität Busterminal" and get off at the stop "Prinzenweiher/DJH" (six stops). On Sunday, bus 124 does not operate. You can travel either to Ilseplatz by Bus 102 (11th stop), and walk from there (about 7 minutes), or you may check other options here: (von: Saarbrücken Hbf, nach: Saarbrücken, Europa Jugendherberge).
  • For Hotel Kaiserhof, take the tramway S1 with destination "Sarreguemines", "Brebach", or "Kleinblittersdorf" and get off at the stop "Uhlandstrasse" (five stops).
  • For the Etap-Hotel, take the tramway S1 with destination "Sarreguemines", "Brebach", or "Kleinblittersdorf" and get off at the stop "Kieselhumes". (six stops).

Specific bus queries (using the names of the bus/tram stops) can be entered here (enter the name of the origin bus/tram stop in the "von" field, the destination in the "nach" field, and in the next two, date and time).

Getting to the MPII and back

All buses to the MPII will have "Universität" as part of their destination sign. You get off the bus at the stop "Universität Mensa". The MPI building is located on the left side a bit further down the street (Building number E1.4). You can also look at the map below. On the way back you depart from the same bus stop (other side of the road).

  • From the main train station and from Hotel B&B Saarbrücken, take bus 124 with destination "Universität Busterminal" and get off at the stop "Universität Mensa" (12 stops). On the way back, the destination is "Betriebsbahnhof".
  • From the city center (Hotel Madeleine is located here) several buses to the MPII (stop "Universität Mensa") start at the bus stop "Rathaus": bus 101 with destination "Dudweiler Dudoplatz" (10 stops), bus 102 with destination "Dudweiler Dudoplatz" (13 stops), bus 109 with destination "Universität Busterminal " (13 stops), and bus 150 with destination "Neuweiler Sternplatz" (10 stops). On the way back to the city center you get off the bus at the bus stop "Johanneskirche". The destinations are "Füllengarten Siedlung" for bus 101, "Altenkessel Talstrasse" for bus 102, "Saarcenter/Goldene Bremm" for bus 109, and "Saarcenter" for bus 150.
  • From the Hotel Kaiserhof (tramway stop "Uhlandstrasse") or the Etap-Hotel (tramway stop "Kieselhumes") take the tramway S1 back in direction main station (destinations "Siedlerheim" and "Riegelsberg Süd") and get off at the tramway stop "Johanneskirche" (three/four stops). Walk over to the bus stop "Rathaus" and proceed as above.
  • From the Youth Hostel (bus stop "Prinzenweiher/DJH"), you enter the bus at the same stop you left when coming from the train station and go on to "Universität Mensa" taking bus 101 with destination "Dudweiler Dudoplatz", bus 124 with destination "Universität Busterminal", or bus 150 with destination "Neuweiler Sternplatz" (seven/six stops). On the way back, the destinations are "Füllengarten Siedlung" (bus 101), "Betriebsbahnhof" (bus 124), and "Saarcenter" (bus 150).

Campus map

ADFOCS supports the recommendations of the SafeTOC report to combat harassment and discrimination in the Theory of Computing community.

By participating in the ADFOCS program, you agree to not exercise any demeaning, discriminatory, or harassing behavior and speech. More precisely, we will adhere to the guidelines as recommended by the ACM/STOC code of conduct.

If at anytime you feel unsafe, intimidated or harrassed during ADFOCS, please contact the organizers immediately and we will start an (anonymous) investigation.

The organizers reserve the right to remove any participant from the ADFOCS summer school.