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progcompcl · 6 years

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The Chilean Competitive Programming Training Camps

Every year, as progcompCL we organize the Competitive Programming Winter Camp in Chile (the acronym in Spanish, ICPCCL), with the collaboration of one of the main universities in Chile and sponsors of the industry.

Our goal is to both gather students with interest in programming competitions, such as ACM-ICPC and similar, from all over the country, and to encourage competitors to learn new techniques and train harder to become better programmers.

Each year the Training Camp has gathered about 80 undergrad students from the main universities of Chile in a 10-day school of algorithms, data structures and strategies for programming competitions. Since the first Training Camp in 2015, the level of our country increased substantially compared with previous years. Additionally, almost every year since, a Chilean team has classified to the ICPC World Finals with their performance steadily increasing.

The format of the Training Camp is as follows. Each day consists of lectures and problem discussions (morning), and programming contests (afternoon). The lectures are given by invited professors from different local universities or former World Finalists. The training camps are free of charge, and we offer travel grants for students who need it. We use all the sponsorship to finance travel grants and various expenses (mostly coffee breaks).

The first Training Camp (2015) was held in Universidad Técnica Federico Santa María (UTFSM), in Valparaíso, July 13-22, 2015. About 80 people attended from 13 universities and 2 high schools (students training for the International Olympiad in Informatics). Students attended from Universidad de Chile (UCHILE), Pontificia Universidad Católica (PUC), Universidad de Concepción (UdeC), Universidad Técnica Federico Santa María, Universidad Diego Portales (UDP), Universidad de Santiago (USACH), among others. The professors were Diego Arroyuelo (UTFSM), Francisco Claude (UDP), and Jorge Pérez (UCHILE), plus former competitors and World Finalists: Nico Lehmann and Rodrigo Alonso (currently working in a U.S. startup IntroLogic). The sponsors of that year were Microsoft, Google, Facebook and NIC Chile, while Facebook and Google sent engineers to talk about internship and full-time opportunities.

http://campamento2015.progcomp.cl/

The second Training Camp (2016) was held in Universidad de La Serena, in La Serena, July 18-27, 2016. About 65 people attended, from 10 universities and a few different high schools. Professors were Jorge Pérez (UCHILE), Diego Seco (UdeC), Nico Lehmann (IntroLogic), and Rodrigo Alonso (IntroLogic). Sponsors were Facebook, U-Planner (Latin American company, sent an engineer to talk about job opportunities), and NIC Chile.

http://campamento2016.progcomp.cl/

The third Training Camp (2017) was held in Universidad de Concepción, in Concepción, July 17-26, 2017. 89 students attended from 11 universities, including a student from Mexico, and a few different high schools. Professors were Juan Pablo Paulsen (UCHILE, former World Finalist), Felipe Contreras (UCHILE, currently working in Synopsys Chile, former World Finalist), Javier Marinkovic (UCHILE, former World Finalist), and Jorge Pérez (UCHILE). Sponsors were Facebook, NIC Chile, Synopsys Chile, and progcompCL (our organization).

http://campamento2017.progcomp.cl/

The fourth version (2018) was held in Universidad Diego Portales in Santiago, July 17-27, 2018. More than one hundred students registered, including students from Bolivia and Colombia. Sponsors included Adessa Falabella, Microsoft, Synpsys, NIC Chile, and Botlab. Professors were Javier Marinkovic (UCHILE, World Finalist), Bernardo Subercaseaux (UCHILE), Pablo Messina (PUC, professor of Competitive Programming course), and Jorge Pérez (UCHILE, professor).

https://campamento2018.progcomp.cl/

We are a team of former competitors (Engineers, PhD students, professors) from Universidad de Chile and Universidad de Concepción, under the name of progcompCL (”Programación Competitiva en Chile”), who have been organizing the Training Camps and also the local Olympiad in Informatics for school students (the Olimpiada Chilena de Informática, or OCI). Some of us also helped organize the first Hour of Code event in Chile, in 2015.

Links:

Promotional posters: https://progcomp.cl/private/171569955344/tumblr_p553r955S11tz1zcd

Main site: https://progcomp.cl

Photos https://www.flickr.com/photos/progcompcl

Social media (twitter/fb): progcompCL

YouTube w/lectures: https://www.youtube.com/channel/UCmVg7YyMS8H-65WCmkVHB9g

#training camp #competitive programming #acm-icpc #icpc #acmicpc #chile #icpccl #programacion competitiva

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progcompcl · 7 years

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#QuestStgo

Las quests han vuelto, y no en forma de fichas.

Así es, señoras y señores. Porque ustedes, 5 personas, lo quisieron, ¡las quests han vuelto!

¿Quests? ¿Quést eso?

Las quests son pequeños desafíos que se deben cumplir y mostrar al mundo que se cumplieron por Twitter (sí, Twitter). Por ejemplo:

#QuestYoVoy: Tuitea al mundo que irás a la #ICPCStgo este fin de semana

#QuestUniversidad: Publica una foto tuya frente a tu universidad. ¡Puntos extra si es con tu equipo!

#QuestDespacito: Publica un video tuyo cantando un verso de esta canción

En la cena de premiación de la ICPC daremos un reconocimiento y uno que otro engañito (un premio) a los primeros lugares. Cada quest te dará puntos, y quienes obtengan la mayor cantidad de puntos serán los ganadores.

Quien obtenga más puntos será coronado Rey/Reina de las Quests 2017

¿Y cómo participo?

Fácil. Si eres parte de un equipo que irá a la ICPC este 10 y 11 de noviembre (ya seas competidor/a o coach), asegúrate de incluir tu cuenta de Twitter en el sistema de Baylor (cuando registras tus datos para la competencia: icpc.baylor.edu/private/profile/myicpc ) y ya puedes participar.

Para cada quest tienes que incluir el hashtag #ICPCStgo y el de la quest correspondiente, por ejemplo:

Yo voy a la ICPC a ganar! 💪 #ICPCStgo #QuestYoVoy

¿Dónde veo quién va ganando y las quests disponibles?

Acá: http://myicpc.icpcnews.com/southamerica-south-2017

O en corto: http://bit.do/QuestStgo

¡Iremos agregando quests durante todos estos días!

Eso es todo. Nos vemos este fin de semana!

Abrazos,

Wax Cathy Pato (former Quest King)

Reglas

Cada participante debe inscribir una cuenta única y personal, con la cual se le identificará para sumar el puntaje.

Los puntajes se asignan individualmente. Cada tuit suma puntaje a una sola persona, aún si es una fotografía en la que aparece más de un participante.

El puntaje correspondiente a un desafío se asignará una sola vez (múltiples tuits relacionados a la misma quest solo cuentan como uno), a menos que el desafío diga explícitamente lo contrario.

Un mismo tuit puede servir para completar más de un desafío siempre y cuando cumpla con lo descrito en cada desafío involucrado e incluya todos los hashtags correspondientes.

Los desafíos tienen un periodo de duración. Fuera de este plazo, no se asignarán puntos.

Para ganar NO es requisito haber completado todos los desafíos.

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progcompcl · 7 years

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Soon... Se viene la final nacional! 💪

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progcompcl · 7 years

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¡Atención estudiantes de enseñanza media de Santiago! La USM campus San Joaquín realizará el taller "Yo C más" para aprender a programar a contar de junio. Las clases serán jueves y viernes de 15.30 a 17:30 hrs. Este taller te preparará para participar de la Olimpiada Chilena de Informática ;) Inscríbete en www.admision.usm.cl/yocmas

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progcompcl · 7 years

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¡Buscamos a alumnas y alumnos de 1° a 4° medio que quieran aprender a programar en Java!

Este taller de preparación para las Olimpiadas Chilenas de Informática tiene como objetivo enseñar el razonamiento que se utiliza para resolver problemas de programación competitiva. Va dirigido a alumnas y alumnos de media para incentivar la computación en jóvenes, por lo que no es necesario que sepan programar desde un principio. La iniciativa está impulsada por alumnos de computación de la Pontificia Universidad Católica de Chile. Las clases se realizarán todos los sábados en el campus San Joaquín a partir del 17 de junio hasta el 30 de septiembre y no tienen cobro alguno. Para más información este es el link al programa del curso, donde se encuentran los contenidos, calendario y metodología:

https://drive.google.com/file/d/0BxLTZEeju4rySlBaOGRBbjNkRzQ/view?usp=sharing

El único requisito para las alumnas y los alumnos es que vengan con la motivación y ganas de aprender!

Inscríbete en: https://goo.gl/forms/AEgmJF4RBDNm8VpQ2

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progcompcl · 7 years

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ACM-ICPC World Finals 2017

Durante las 5 horas, el equipo compuesto por Robinson Castro, Juan Pablo Paulsen y Javier Marinkovic, resolvió 4 problemas. Este es un record para nosotros en una competencia mundial. En tiempo de competencia, los chicos fueron el primer equipo de latam en resolver su tercer problema y el segundo de latam en resolver su cuarto problema después de menos de dos horas de competencia, lo que los tuvo por gran parte de la competencia liderando el ranking de los latinoamericanos. Por las reglas del torneo los problemas que no se resuelven al primer intento llevan una penalización en tiempo. Esto dejó finalmente a nuestro equipo detrás de dos equipos de Brasil y dos de Argentina que también resolvieron cuatro problemas pero sin penalización. A pesar de que los chicos tuvieron más de dos horas para tratar de resolver su quinto problema, lo que los habría dejado top 1 en latam, no lo lograron. Obvio que 5 minutos después de terminada la competencia se dieron cuenta de los errores en dos de los problemas que estaban tratando de resolver ;-) pero así es la competencia. El equipo cubano de la Universidad de La Habana, sí logró resolver un quinto problema, lo que los dejó como campeones de latam en esta competencia. Nosotros quedamos finalmente 6to de latam, superados por el equipo de La Habana, seguido por Univ. Nacional de Córdoba, UBA, y dos brasileras que no recuerdo. Cabe destacar que nuestro equipo superó a los 12 restantes de latam que incluyen a 4 equipos de Brasil, 3 equipos de México, y equipos de Argentina, Bolivia, Colombia, Perú y Venezuela. Nuestra siguiente meta como grupo de programación competitiva es pelear el primer lugar de latam en una final mundial! Para que se hagan una idea del nivel de esta competencia, nuestro equipo superó a equipos de universidades como Princeton y Oxford! La mejor Universidad de Norte América es Waterloo, y en los primeros lugares no figuran ni MIT ni Berkeley ni Cornell que son las otras top de USA que clasificaron (Cornell virtualmente empató con nosotros). La competencia general está desde hace varios años liderada por rusos y asiáticos que son capaces de resolver 10 problemas en 5 horas, realmente impresionante! Este logro es realmente meritorio y es 100% por el esfuerzo de nuestros brillantes alumnos. El dejar por un tiempo de lado algunas responsabilidades académicas para prepararse y competir les ha enseñado mucho y abierto bastantes puertas. Juan Pablo estuvo hasta inicios de mayo en una práctica en Google y seguramente le ofrecerán otra pues fue "top-performer". Robinson estará todo el segundo semestre en una práctica en una empresa de Software en Brasil y tiene ofertas para el verano de Microsoft y Facebook. Javier seguramente recibirá ofertas pronto de algunas empresas de high tech. Ojalá se quedaran en Chile trabajando, pero será redifícil retenerlos :'-( ¡Felicitaciones otra vez a los chicos!

#ACM-ICPC #Rapid City #World Finals #Chile #2017

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progcompcl · 7 years

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¡El evento más esperado del año ha vuelto! 😁

El Campamento es una instancia para aprender técnicas de algoritmos y estructuras de datos aplicados a Programación Competitiva y poder llevarlos a la práctica resolviendo desafiantes competencias de programación. Consiste en tres tipos de actividades: clases expositivas de temas avanzados, talleres de programación simulando competencias reales, y sesiones de discusión.

El Campamento se llevará a cabo en la Universidad de Concepción entre el 17 y el 26 de julio de 2017.

http://campamento2017.progcomp.cl

El primer llamado a inscripciones cierra el 31 de mayo de 2017, a las 23:59:59 horas (más o menos).

#programacion #competitiva #informatica #computacion #concepcion #chile #escuela #invierno #acm-icpc #ioi #oci #campamento

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progcompcl · 7 years

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El primer lugar en la Hackathon Solar obtuvo un equipo del DCC integrado por el académico Jorge Pérez y los alumnos de postgrado Mauricio Quezada y Nicolás Lehmann, y de pregrado, Juan Pablo Paulsen y Robinson Castro, quienes participaron en la categoría Start-Up como grupo de Programación Competitiva en Chile (@progcompCL).

#hackaton #hackathon #data science #energia solar #solar energy #corfo #fcfm #dcc #uchile #cdec #cne #bid #comite solar #energia abierta

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progcompcl · 8 years

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[acm-icpc-latam] Answer to the "Open complaint letter to ICPC Latam"

Please distribute. This is an answer to the “Open complaint letter to ICPC Latam”, published at http://progcomp.cl/post/153200885939/open-complaint-letter-to-icpc-latam.

Campinas, 16 November, 2016 To: Signatories of the “Open complaint letter to ICPC Latam” (at http://progcomp.cl/post/153200885939/open-complaint-letter-to-icpc-latam) From: Prof. Ricardo Dahab IC-UNICAMP Director of Contests, ICPC Latin America

In this letter I would like to address a few concerns and statements put forward in your letter, a few of which convey a wrong impression to the general public on the workings and motivations of the Latin American ICPC Contest direction. Before that, I would like to mention a fact that by now is common knowledge, namely that an appeal has been addressed to me and to the head of judging of the Latin American ICPC, Prof. RIcardo Anido, by coach Jorge Pérez. The appeal asks for reconsideration of the decision to disqualify de U of Chile team “El equipo de Paulsen” from the 2016 Regional Contest. I quote from the answer to the appeal:

The ICPC Latin American Steering Committee has reached a decision regarding your appeal. Considering all the attenuating facts surrounding our decision to disqualify the UChile team, taken in a state of near emergency in the morning of contest day, we have decided to revoke the disqualification and consider the team’s solutions stored in the BOCA system as official. Had the team not been disqualified, it would have earned one of the 18 slots already assigned to Latin American teams. Fortunately, recognizing the extreme circumstances of this case, Bill Poucher, Executive Director of the ICPC, has allocated one extra finals slot to the Latin America Region, which will be used to promote UChile’s team to the 2017 ICPC Finals in Rapid City, USA. We hope that you recognize that our decision to disqualify the team was not taken lightly, neither with intention of harming the UChile team or Nico Lehmann. As we said in our statement that day, we acted “without risking any assumptions regarding the integrity of those involved in these issues”. We saw some real conflicts of interests that ought to have been put forward by Nico Lehmann regarding problem E, but were overzealous regarding the other problems. By trying to preserve the contest’s integrity and reputation, we have failed to prevent an injustice that we now correct.

I now proceed with my comments regarding your open letter:

But the committee decided to disqualify the team giving the message to the team that they have been disqualified because they cheated. Although the committee did not use those words, there is nothing else that a team could understand in a situation like this.

Comment 1: This was not at all what we meant. We never said or hinted that the team had cheated. Actually, in the letter we wrote in the morning of the contest, in which the disqualification was announced, we made it very clear that we were not making any assumptions regarding the team’s integrity. We may have been overly cautious, but we were also very much upset by the fact that Nico Lehmann never said a word about all the connections of which he was part, namely proposing the problem to the ICPC and later presenting a solution to that problem at the IOI conference having as coauthors members of the UChile team. In a context where trust is a paramount requirement, we could not take chances, at the risk of losing all credibility we have worked so hard to earn over the past twenty years, with the invaluable help of our Chilean friends as well, let me add. So, if we were cautious, we had reason to be, and acted on it by expunging the problem from the set. If we were then overly cautious by disqualifying the team and the result was an injustice, that was corrected by revoking the disqualification. However, even hot headed as we were by all that was going on the contest morning, we have never falsely suspected of any wrongdoing by the team. By recognizing that we may have committed an injustice, we are reaffirming our trust in the people we work with and the faith in the students. Trust is a two-way street, though. The community must also trust that we act in its best interest, even if an injustice here or there is committed.

Comment 2: I vehemently protest that statement. I do not think we are giving that message at all. We do encourage sharing, and that is evident in the way the problem committee works, in a very openly manner, with open calls to contributions, naming the problems’ authors and so on. However, it is a model that works under the assumption of total trust. When that trust in tainted the way it was, by Nico Lehmann’s silence, we can’t be expected to react in any other way but with indignation. Sharing, learning and competing together is at the very base of what we do from day one, this is how the contest is built.

We expect that future decisions of the committee will be made considering the points we exposed, in order to preserve the spirit of the ICPC.

Comment 3: We also *hope* that we can proceed as we always have, preserving the spirit of the ICPC we have ourselves worked so hard to build. Involuntary mistakes are part of the human experience and we have made our share of such mistakes over the years; however, it is how we react to them that counts.

Several coaches and ICPC problem setters attended the presentation of the paper, including some Latin American members of our community. Also notice that the venue was the International Olympiad in Informatics, and Ricardo Anido (ICPC Latam, Director of Judging and Problem Committee) is a member of the International Committee of the IOI

Comment 4: Prof. Anido was, indeed, present at the IOI where Nico presented his paper. However, he was attending other IOI meetings and not the conference. I fail to see the importance of this statement to your argument; it may even give grounds to suspicion. I believe it should clarified since he is a central piece in all that happened during the last weekend. I would like to end this letter by showing my appreciation to the participating students and all the volunteers who contributed to the Regional Contest this year. Special thanks go to:

The problem committee that, aside from producing another flawless set, had to see it ruined by the removal of a very interesting problem. Working on a set takes an enormous effort from volunteers. It is equally very frustrating to see it wasted for the wrong reasons;

the RCDs and friends who helped me think through the subtleties and pitfalls of this exceptional situation;

Bill Poucher, Executive Director of the ICPC, for offering his help yet again;

Federico Meza, Chile Site Director, who had the unfortunate mission of conveying to the UChile team the decision to disqualify it. He did with the usual care.

Ricardo Dahab

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progcompcl · 8 years

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Open complaint letter to ICPC Latam (UPDATED)

UPDATE 1 (2016-11-17): After a formal appeal by the coach of the involved team and some members of Universidad de Chile, the ICPC Latin American Steering Committee decided to revoke the disqualification of the team. The formal response, which is completely transcribed at the end of this letter, is summarized in the following sentence by the ICPC Director of Contests, Latin America

“By trying to preserve the contest’s integrity and reputation, we have failed to prevent an injustice that we now correct.”

We sincerely thank the ICPC Latam Steering Committee for considering all the facts and point of views in this new decision.

UPDATE 2 (2016-11-17): The answer to this letter from Ricardo Dahab is available in http://progcomp.cl/post/153324698674/acm-icpc-latam-answer-to-the-open-complaint

Dear Directors of ICPC Latam,

We hereby wish to present a formal complaint from the Chilean ICPC community, with regard to the disqualification of the Chile-14 team, “El Equipo de Paulsen”, which represented Universidad de Chile in the South America/South regional contest held on Saturday, November 12th 2016.

The facts:

A paper titled “Wavelet Trees for Competitive Programming” was published at the IOI conference 2016, with Robinson Castro, Nico Lehmann, Jorge Pérez and Bernardo Subercaseaux as authors. The paper showed several applications of the Wavelet Tree data structure for ICPC-like problems.

Jorge Pérez is the coach of the Chile-14 team, and Robinson Castro is one of the team members.

Nico Lehmann proposed a problem for ICPC Latam 2016 which could be solved with Wavelet Trees. This problem was accepted to be included in the 2016 contest as problem E, called “Emission Spectrum.”

The night before the contest, the Latin American committee raised the alarm on the existence of the aforementioned paper claiming a possible conflict of interest, thus decided to remove problem E from the 2016 contest.

Ultimately, the committee asked the team Chile-14 to voluntarily resign to compete thirty minutes before the start of the contest. The Chile-14 team did not resign, hence the committee decided to disqualify the team.

This has been both an unexpected and unfortunate situation for us. We would like to stress very clearly that we do believe that by no means the Chile-14 team and Nico Lehmann sought to profit from the situation described above, or to behave in ways against the integrity and reputation of the ICPC contest. Nico Lehmann disseminated his work on Wavelet Trees well beyond Universidad de Chile, and therefore we consider that his sole mistake in this situation is that he should have strived to disseminate the paper presented at the IOI conference even further than he did before the ICPC contest took place.

Our point of view

First of all we want to state the following:

We trust that before the contest, the Chile-14 team was completely unaware about the ideas, contents and format of Problem E that was going to be included, or any other problem in the contest in that regard.

We trust that the intention of Nico Lehmann was not to propose a problem to give an unfair advantage to some teams over others, but only to propose a challenging problem for all the teams in Latam, and he had no intention to hide possible conflicts of interest.

The above statements cannot be formally proven. We just want to make as clear as possible that none of us believe that there is anything beside an error and a misunderstanding and that we do trust that the mentioned members of our ICPC Chilean community acted honestly and honourably. We provide additional background and facts to support our claims in the next section of this letter.

We do believe that the Latin American committee made a bad and unfortunate decision on disqualifying the team in the way they did, and these are our main reasons to assert this:

Putting the integrity and reputation of the contest over the people involved. This is possibly the most important aspect. The official note by the committee stated that their decision was “in the interest of preserving the contest’s integrity and reputation”. In preserving that integrity they forgot that this contest is, over all the other things, an event for people, an event whose spirit is not to only state who is better than the other, but to friendly cooperate and learn together. In preserving the integrity and reputation of the contest they forgot that there is hope, dreams, and love for Computer Science in all the participants. When one puts the “reputation of an event” over the good and fair treatment of any of the members of a community, the ethics and values of a human competition are evidently hindered. In this case, the disqualified team was informed of the decision without even being listened to, considering only one side of the story. You may not understand how hopeless the participants felt in that moment, a feeling that is going to last for a long time, especially for one of the members for whom this was his last eligibility year to compete.

The timing of the communication. The team disqualification decision was informed to the affected contestants only a couple of minutes before the start of the competition. We acknowledge that the committee had a short time to decide its course of action, nevertheless, we consider that the severe decision taken was hurried, and communicated to the affected parties in a way that we deem improper. Given the time frame, a cautious way to proceed would have been to postpone any decision or communication regarding the involved team to be taken after the contest and after having conducted a thorough investigation. This is how these problems are usually resolved in other similar competitions.

The reason to put forward both, deletion of the problem and disqualification. It is indeed acceptable that the committee decides to remove a problem from the set if they think it would bring an unfair bias to the contest. This is in the contestants’ best interests. In that respect one may agree with the committee decision of deleting problem E given the known facts, and their belief that this would give an unfair advantage to some of the teams. Allowing the disqualified team in the competition would have not introduced any unfair bias to any of the other competing teams, besides potentially seeing more balloons in the scoreboard that would have been deleted if the team was disqualified later (but we know that this bias currently exists given that not all sites can see the scoreboard of other sites). But the committee decided to disqualify the team giving the message to the team that they have been disqualified because they cheated. Although the committee did not use those words, there is nothing else that a team could understand in a situation like this.

We think that the way in which the committee acted is giving several wrong and misleading messages to the ICPC community. In particular, the damage produced is not only to the mentioned team, but also to the whole community. From our point of view, the decision is against the very notion of sharing material, learning together, and developing new skills as a group. At least in Chile we have this spirit regarding ICPC, which can be witnessed very clearly by the letter that the team from Universidad de Talca wrote after the competition.

We expect that future decisions of the committee will be made considering the points we exposed, in order to preserve the spirit of the ICPC.

Background facts and information

We believe that there are important facts that were not considered by the committee at the time when the decision was taken. We acknowledge that they had very little time to decide but we would like to point out some of them.

About the Wavelet Tree

The Wavelet Tree is a data structure that is more than 13 years old (Grossi et al. 2003). In fact, “Wavelet Tree” is a new name for a data structure that has been used by the Computational Geometry community since the 80’s (B. Chazelle, 1998), and the paper by Grossi et al. (2003) only showed some new applications and a succinct implementation. Moreover, it is a standard data structure nowadays having an entry in the Encyclopedia of Algorithms (Grossi 2014), an extensive survey by Gonzalo Navarro (2012), several application papers, a wikipedia page, several blog posts, and has been already used by Asian contestants for some time. Several of the main functionalities of the Wavelet Tree, such as k-quantile and median queries, can be achieved with data structures like Persistent Segment Trees or Merge Sort Trees, techniques that are very well known by the more experienced programmers in our region, but still not widely used in countries with less experienced ICPC contestants.

Thus, the paper was not proposing anything new, not introducing an unknown topic but only making more accessible some techniques for less experienced contestants and increasing the possibilities for problem setters and judges.

Publication of the paper

Please notice that the paper “Wavelet Trees for Competitive Programming” was openly published (with all authors’ names and affiliations), there is public code available, the presentation of the paper was also public, and the venue was a typical venue to present applications of known data structures to ICPC-IOI problems. Other typical structures and algorithms, like the Hashing method for string processing, Fenwick Trees adaptation for Dynamic Range Minimum Queries, etc. have been presented in a familiar way for programmers in the same conference.

To test the problems for the Wavelet Tree in the mentioned paper, the authors contacted Brazilian and Mexican contestants to produce alternative solutions.

These facts show that had Nico Lehmann wanted to hide his connection to the paper, he made a terrible choice of a strategy. Actually, it seems to be exactly the opposite; the evidence shows that Nico’s intention was to disseminate the knowledge that he and his coauthors had generated with utmost enthusiasm.

People of the Chilean ICPC community endorsing this letter:

Claudio Álvarez Former coach, Universidad de los Andes, Chile

Diego Arroyuelo Coach, Universidad Técnica Federico Santa María, Chile

Ricardo Baeza-Yates Former coach, Universidad de Chile Former member of the Latin American ICPC Steering Committee

Jorge Baier Former coach, Pontificia Universidad Católica de Chile Former contestant and judge

Sebastián Barbieri Former contestant, ICPC World Finalist

Ricardo Barrientos Coach, Universidad Católica del Maule, Chile

Patricio Beckmann Coach, Universidad Diego Portales, Chile Former contestant

Miguel Campusano Former coach, Universidad de Chile Former contestant

Ruben Carvajal-Schiaffino Coach, Universidad de Santiago de Chile

Francisco Claude Coach, Universidad Diego Portales, Chile Former contestant, ICPC World Finalist

Felipe Contreras Former contestant, ICPC World Finalist

Dietrich Daroch Coach, Pontificia Universidad Católica de Chile Former contestant

Catherine Espinoza Chilean deputy leader IOI Former contestant

Camilo Garrido Coach, Universidad de Chile Former contestant

Andrés Letelier Coach, Pontificia Universidad Católica de Chile Former contestant

Francisco López Coach, Universidad de Santiago de Chile - Ingeniería, Chile Former contestant

Gonzalo Navarro Professor, Universidad de Chile Editor in Chief, ACM Journal of Experimental Algorithmics

Jorge Pérez Coach, Universidad de Chile

Mauricio Quezada Coach, Universidad de Chile Former contestant

Erik Regla Coach, Universidad de Talca, Chile Former contestant

Rodrigo Salas Coach, Universidad de Valparaíso, Chile

Nicolás Sanhueza Former contestant, ICPC World Finalist

Diego Seco Coach, Universidad de Concepción, Chile

Romina Torres Coach, Universidad Andrés Bello Former contestant

Oscar Valdivia Verdugo Coach, Universidad Diego Portales, Chile Former contestant

Victor Vasquez Coach, Universidad Católica de La Santísima Concepción, Chile

References

R. Castro, N. Lehmann, J. Pérez, B. Subercaseaux (2016) Wavelet Trees for Competitive Programming, IOI Conference

B. Chazelle (1988) A functional approach to data structures and its use in multidimensional searching, SIAM J. Comp. 17 (3) (1988) 427-462.

R. Grossi (2014) Wavelet Trees, Encyclopedia of Algorithms, Springer Science+Business Media New York 2014

R. Grossi, A. Gupta, J.S. Vitter (2003) High-order entropy-compressed text indexes, In Proceedings of SODA 2003 pp 841–850

G. Navarro (2012) Wavelet Trees for All, In proceedings of CPM 2012: 2-26

Response from the ICPC Latam Steering Committee:

Dear Jorge, Éric, Ricardo and Gonzalo,

We hope that you recognize that our decision to disqualify the team was not taken lightly, neither with intention of harming the UChile team or Nico Lehmann. As we said in our statement that day, we acted “without risking any assumptions regarding the integrity of those involved in these issues”. We saw some real conflicts of interests that ought to have been put forward by Nico Lehmann regarding problem E, but were overzealous regarding the other problems. By trying to preserve the contest’s integrity and reputation, we have failed to prevent an injustice that we now correct.

Sincerely,

Ricardo Dahab ICPC Director of Contests, Latin America

#acm-icpc #icpc2016 #competitive programming #ioi #oci #maratona #tap #argentina #brasil #brazil #peru #bolivia #colombia

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