A few people expressed interest in me answering some questions regarding competitive programming/problemsetting/related stuff. Since I have a bit of free time during these holidays, let's try this. I'll choose a few most interesting questions from comments under this post and try to answer them in a single video.

Ideally a question should not be to broad ("please give us some tips and tricks" is probably too broad) and possible to answer within a few minutes. I probably won't answer a question if it was asked a lot of times here on CF/quora/someplace else. Let's go!

Looking for a training partner. No joke.

I am already qualified for IOI but my country doesn't have any training camp nor good partners, so looking for students planning to qualify and participate at IOI.

I want to add numbers to a set of integers and answer a query how many numbers are there which are less than a given number K. What is an efficient way to implement this other than BIT?

Hello Codeforces! Being the lowest contributor, I might not be the right person to say this, but let's please follow the rules.

Codeforces does not allow creating new accounts to participate in a contest, you can see it here. This is probably because it affects other user's ratings. However, it seems like a lot of Div 1 coders violate this rule to get their names seen on the Div 2 contest's official standings. Lets' take a look at recent Div 2 contests; Codeforces Round #460, Codeforces Round #459, Codeforces Round #457... Actually most of the Div 2 contests have unrated contestants on the top 10.

Now let's see how does MikeMirzayanov see this situation. Well it seems like "It's ugly, unethical, disrespectful to him and the community."

The most recent obvious and shameless "cheating" I have seen is this. Even right now UoA_Akane is participating in the current Div 2 round. Although I don't have a solid evidence, doesn't it look like the real user behind all those account is qingczha?

How can we stop this, Mr.MikeMirzayanov? Codeforces could improve their verification system. Maybe verifying an account through a phone number? Since those people's goal is to get ranked top on the leaderboard, Codeforces could stop displaying unrated users on the leaderboard? Unrated users will still get their rating changed so it won't affect the real unrated users.

However, this problem could be easily solved if those Div 1 participants just start participating unofficially. So I kindly ask you guys to stop doing this unethical thing, as it affects other Div 2 users.

MikeMirzayanov someone is threatening to kill me! Please help me!

Where can I report bad people? Emiway This person just harassed me.

Codeforces Rounds 451 and 452 were based on municipal stage All-Russian Olympiad of Informatics 2017/2018 year in city Saratov. Can someone please explain what is that olympiad and what grade students are participating? Also, are official problems same as the problems of Rounds 451 and 452?

Why is chatting during contest not allowed for new members? Maybe to avoid someone asking for a solution.But I am currently participating in a team contest with a teammate from CodeForces and now I can't chat with my teammate. You ruined my contest.

Admins!!! Please make my last round unrated for me. My stomach hurt really bad during the round so please subtract 15 minutes from my problems or make it unrated. I had to poo for 15 minutes.