Recently, I've had a wish to sit down with great competitive programmers that I find interesting and pick their brains about different topics. For the first iteration, I talked to my good friend Pajaraja, as I'm sure he's unknown to many of you, but he's well known in Serbia as one of the best — both problemsetters and competitive programmers (and especially competitive mathematicians).

Some of his accomplishments:

• 2x Gold medalist at the International Mathematical Olympiad (as well as a Silver medalist)
• Silver medalist at the International Olympiad in Informatics
• 3x ICPC World Finals participant (including a recent 15th place in Luxor)
• IOI Problemsetter (IOI 2021 — Fountain Parks)
• Google HashCode finalist
• many more!

We discuss differences between competitive math and competitive programming, problemsetting, his motivation, pressure and success among other things. Link in case the embed doesn't work.

As a special treat, we decided to prepare a problemset from some of the best tasks Paja set over the years. For most of these, this is the first time they have been translated to english and shared publicly. They have been selected by Paja and me to have a variety of difficulties, from div2C to div1E/F — we believe everyone (from newbies to legendary grandmasters) will find something interesting to do.

We prepared two versions (with same tasks) — one is sorted (according to our thoughts), with subtasks (for individual practice), the other is shuffled, with ICPC scoring — this version is great for people practicing for team competitions. You can find both versions in this group. If enough people do it and like it, we can do a follow up problem analysis :)

Even if you don't have the time to watch our discussion, I highly recommend you check out the problemset!