Dusko Obradovic is a notable figure in the programming and education spheres in Serbia. He embarked on his programming journey during his secondary education in Sombor, where he was introduced to programming concepts in a mathematical class. Later, he transitioned from Pascal to C++ in 2014, recognizing its advantages, especially for students in competitions.

Since 1991, Obradovic has been working at Sombor Gymnasium, except for a brief period from 1993 to 1997 when he worked as a programmer in a software company. He has a strong focus on competitive algorithmic programming, achieving significant success with his students. Several of his former students now work for renowned companies like Microsoft and Nordeus.

His accolades include leading his school team to victory in the High School Programming League 2012/13 and consistently participating in all 15 Microsoft “Bubble Cup” Finals. Obradovic has been recognized for his outstanding contributions to education, receiving prestigious awards such as the “Svetosavska nagrada” from the Serbian Minister of Education and the “Charter of the City” from Sombor.

Despite his programming achievements, Obradovic also prioritizes outdoor activities. For the past 18 years, he has organized nature expeditions for his students, involving canoeing, mountain climbing, and wilderness camping, covering over 1000 km per season. Additionally, Obradovic participates annually in the international programming competition CodeIT, where he not only guides his students but also competes alongside them, showcasing his dedication to both their development and his own continuous learning.

With a strong commitment to both programming and outdoor education, Obradovic continues to inspire and lead his students, fostering their talents in various domains.

For DevStyleR, the man who learned to code without a computer – Dusko Obradovic shares more about the importance of programming in his life, reveals to us the secret of a successful and beloved leader, and what it feels like to stand next to his students during CodeIT.

What does programming mean to you and how did your love for it develop?

At first, programming was just my job. Fortunately1, my programming career lasted for only 3 years. I had been working in a firm which made programs for accounting, and those challenges faded very quickly. For the following 3 years, I was working in Hungary as an entrepreneur in retail. Since 1998 until today I have been working in Grammar School in Sombor as an IT teacher. Ever since then, for me programming is pure pleasure.

You mentioned that you learned to program without a computer. How is that possible?

I suppose that today it would be very difficult. Almost impossible. Not because today’s children couldn’t do it, but because today’s technology makes the process of learning programming easier. At that time, there was no other way. I wrote my first program on a programmable calculator after 15 months of learning from a notebook and a board. I wrote my first program on a computer after 2,5 years, in 1984 in PASCAL on Honeywell. Soon after that, the first personal computers appeared on my faculty, but we didn’t have access like today – one or two times a week, for a few hours, mostly at night. There was no internet for us, mere mortal students.

The school team you lead in Serbia is the only one in the world that has participated in all 16 finals of the Microsoft “Bubble Cup”. How do you achieve such success?

We could say that at the beginning it was just a lucky set of circumstances, which in time grew into something inevitable. Experiences of older teams and their stories year after year inspire new generations to take part in qualification competitions. In the past 8 years, CodeIT qualifications have had the same priority with us as well.

These two competitions, and especially the marathons assignments, are priceless in the process of my students’ advance. Knowing that they have 20 days to solve the problem makes most of them to learn new algorithms and structures in that period so that they would make their placement better.

The fact that you don’t have to catch the beginning of the competition, that even less efficient solutions are also valued and the lack of time penalties all brought to the fact that longer qualification rounds are more popular in my school than the sprint rounds. Even if we put aside those who are satisfied with even getting a shirt, we can say that the fever of CodeIT and Bubble Cup is always present in our school.

You have received numerous awards in Serbia, including the “Svetosavskа Award” and the “Povelja grada”.

Both awards are not just the product of success in programming. Over a month which I spend in nature with my students has equally contributed, if not even more, to receiving those awards. I divide my year into programming season: from the finals of Bubble Cup at the end of September, over winter and spring, until the end of the finals of CodeIT at the beginning of June; and on the adventurous season: during the summer. This other includes camping, fishing and ecological-rowing expeditions. During those, we compensate nine months of cyberspace with the life in a complete natural environment without any comfort.

What is the secret to building a cohesive community that competes among itself in various competitions?

Today’s way of life, which is considered as a contemporary value, and extreme influence of mass media led to the fact that in Serbia there are no more colleagues ready to do something like that. As far as I know, it is similar in Bulgaria as well.
The other reasons are, that those who have the knowledge to pass on to new generations will rather work somewhere else for 2000+ EUR instead for 750EUR, which is the salary for teachers in Serbia.

I wouldn’t call my way of work a secret.

• – With my students I don’t have a typical teacher – student relationship. We are all pals, and in many programming competitions and on CodeIT in finals we compete against each other. (This does not apply when I have to mark them).
• Experiences of earlier generations from their faculties and jobs in IT companies, through the students themselves, their friends and relatives in one small town are easily spread, so many elementary school pupils are coming to my extra classes even before they enroll Grammar School.
• My extra-curricular classes are open to students from other schools as well.
• There are no divisions on gender, classes, religions… so, except on competitions, you can always count on help of those who are around you.
• Many of those students enjoy the natural beauties of Serbia with me, next to some water during a big part of summer in the adventurous season.
• In the programming season I do about 5 hours of extra-curricular classes a week. On the contrary to other professions in Serbia, doing extra hours in teaching is not paid.

How do you prepare students for Olympiads and competitions, and what is the best advice you give them before each event?

Before competitions in our country there is a list of advice that competitors should acquire. That list was based on hundreds of points that previous students had lost on their competitions, and that led to a difference in points on their expense.
Choice of the adequate type of data structures and their sizes.
Obligatory winning the partial points, if there are some.
Narrowing down of the possible ways of solving the tasks based on given limitations.
And many more…

Nemanja Majski is my only student who has achieved this so far. And for more than a year he has been working alone and going to Belgrade at weekends, where he and a few more students have been prepared for the international competitions. This, of course, makes me proud.

Talent or hard work – which one is the key to success?

It depends on what you consider a success. If success is getting a job in an IT company, it doesn’t matter. If the aim is to work in a better firm with a bigger salary, it is possible to achieve with less talent and much work or vice versa.

If success is reaching a level where you can choose where you want to work, you need both talent and a lot and a lot of work.

Now that you have mentioned this, I have to say that it is a big pity that in our two countries a good system doesn’t exist. It all depends on the individual. There are talented children everywhere. The proof for that are not so big towns like Sombor (SRB) and Shumen (BG). Whether they will be found and start their way in which their talent will be fully used, depends on luck as well. You should be born in a town like this or its surrounding at the time when there live enthusiasts who put long-term strategic aims in front of their own personal material ones.

You have been competing alongside your students at CodeIT for years. What do you feel and think when you stand next to them during a competition?

Since the codes are public after the competition, I cannot hide the ways I approach solving of the marathon tasks. Honestly, that is not my aim at all. But during earlier competitions that was my advantage. Tempo in which I type and test, comparing to my students, is certainly my handicap. Even reading the text of the task takes a considerable amount of my time. I still manage to compensate that by experience, but it is getting more and more difficult. It happens more and more often that one or even more of them beat me on the same competition. The last sprint round on CodeIT was a disaster for me. I didn’t manage to solve not one task in given time. My ages are getting me. Luckily, I have no problem with the fact that my students are beating me.

What advice would you give to future participants in CodeIT?

The first piece of advice is to be persistent and patient. I have recently tickled the CodeIT officials to, besides presentation of the Great Guru, organize one of the little Guru, i.e. me, where I would, at least to younger participants, convey a few very useful pieces of advice when solving marathon tasks. If they get lucky and that really happens, in future their results in marathon tasks will certainly be better.

Besides this, play computer games less. That is a waste of time and you have no use from it, but a current satisfaction. Successfully finished combat with the solving of a programming problem can give you a similar feeling, with the difference that this will definitely help you in your future profession.