As far as I noted, Codeforces has had a guide for interactive problem since 2016.
I started Codeforces from middle 2017, and met my first interactive problem on August of that same year (843B - Interactive LowerBound). Honestly, it was a fun experience, though the solution was a bit out of expected convention for interactives.
Ever since, interactive to me has growth in its own way, even appearing in some more local contests as well. Yet, it seems to me that there were still a considerable portion of people having problems with those things even from their mind.
Ever from my first round in early 2019, someone already asked this.
first congrats on your first round second why interactive?
Umm...
Yep, along with that is a major lengthy discussion/prediction on the interactive problem (let's not talk about what happened after that).
Still, at those days, I simply gave them the benefits of a doubt. After all, the problem type is still novel, and there are a quadzillion ways to make an interactive problem function (other than the classic binsearch-simulation).
But that should be a thing back in 2019, right?
Well...
Then I saw this just a few days ago on announcement of Codeforces Round 988 (Div. 3).
...Really?
Okay, okay, but let's just put down my own personal hate on that comment and discuss seriously. If it's just a "new kind of fun", isn't it the same analogy towards the more advanced topics in lower rated participants' eyes? (i.e. flow, 2-SAT; though I honestly won't encourage raw implementations of such in a div3, of course). What is the problem with interactives that give many people an immediate frown even before seeing the problem itself?
The year is 2024 (no it's almost 2025 even what the heck) already, and why are interactives still uniquely discriminated?
(insert some funny propagating hashtags for interactive rights here, I'm a lame guy I can't make up one on the spot XD)
(the discussion I want to raise is still serious though)
People seem to not like problems that are different, and interactive problems typically have a different way than normally expected to solve. It requires a different mindset.
I think interactive problems are kind of fun. They can be frustrating, but they are unique.
People should just create habits for interactive problems, and continue with it as a normal problem. For me in C++, I just make sure to have cout << flush; and to comment out my fast IO. I don't know if that is even necessary, but I make that a habit for interactive problems and I never need to worry about the interactive part of the problem.
Thank you for reading this. I believe that if you struggle with what to do on the interactive portion of the problem, try a few interactive problems out. Try different ways of flushing the output, using the different types of input/output, etc. If you are comfortable with it outside of the contest, you can be comfortable with it inside the contest.
Same here. I (almost) always define all query syntaxes into functions accordingly, then forget about them and do the problems proper.
I think people have different opinions in interactive problems.
In my opinion,I like these problems because it's really interesting and it can widen my sight.
Some of these problem really helped me a lot to learn some algorithm that i have never seen.
Although sometimes it makes my rating dropped,I still enjoy it by its interesting,its unique glamour.
PS:I'm bad in English,but I try my best. :p
TLDR: My own experience on interactive problems, the pattern of thinking is... far different from my solved problem. So it might very frustrating for 1-3 first times encounter, the later is kinda normal.
After a few failed attempts on doing interactive problem on live contest, I read the editorial and learned a few things about it. My lesson is drafting out a more sample cases and queries and make observation on them, actually a LOT of queries...
Then I actually solved the first interactive problem on live contest (Div. 3 988) and have the same idea as the editorial. Very worthy and fun experience tbh.
They are not so much discriminated. Most people are fine with them. Complaints are from those who care much about their rating and is especially bad in interactives.
Yeah, it's indeed on the few. Yet it still amazed me that of all the scapegoats naggers tend to use for excuses, interactive always had a considerable portion.
It's just about preference and about how much people are used to interactive problems. It's still not common to see many interactive problems outside of Codeforces. Even in CF, interactive problems are still taking only a small portion of the problemsets and they are avoided in D2B and easier problems due to the complexity of the problem format, lengthy description of the interaction process, and difficulty for testing. It's not something that's fundamentally hard (unlike the "advanced topics" you mentioned), but is something that you need to learn and spend some time to get used to.
It's no wonder why some people think it's a thing only for high-rated participants, because even if they very occasionally see interactive problems in their range, they can just skip those and it's usually not a huge matter even to reach Experts, and those are indeed the majority of people. For this reason, I'm actually welcome to introduce more interactive problems in somewhere mid-early in Div. 3 with only basic thought process required, so that people can easily get used to them and be prepared to confront them in Div. 2 legitimately.