Not to rain on your parade or anything, but I'm not sure how good that test is, since there seems to be very little information on it, and idk about the algorithm they use to score it / give you the next item. In general, it's best to stay away from community-made or heavily-modified tests on that site. So the best tests there are the:

• $$$AGCT$$$
• $$$GRE$$$
• Maybe the $$$1926$$$ $$$SAT$$$, but I'm not sure about how they redid the norms there.

Basically, any once-real test that was not modified too much is probably your best bet. Like for example the $$$AGCT$$$ is basically the same as it was when it was used in $$$WWII$$$, and the $$$GRE$$$ is just a combination of old $$$GRE$$$ forms when it was still a good measure of general intelligence. And the $$$AGCT$$$'s norms that they use are pretty close to the $$$1940$$$ ones (it appears that the $$$AGCT$$$'s items aren't susceptible to the Flynn effect, which is a sign that they are good items), and the $$$GRE$$$ norms are also very accurate.

It is unclear how good a lot of the other tests are, like almost all of them, since they use their community to make the norms for the tests instead of the general population, which isn't a problem for the above tests (except for the $$$1926$$$ $$$SAT$$$ I think) since they have norms derived from general-population-esque samples. I'm not sure why they don't have a Wonderlic form available since they have many real forms and it would be the best way to find out your $$$IQ$$$ in a very short amount of time.

damn I thought that $$$2027$$$ was $$$2$$$ years from now

This test is one of those tests where the time pressure is a huge part of the score, kind of like the wonderlic (idk if you were ever sent one of those for job applications and whatnot). Also I think it's one of the tests where guessing, on average, shouldn't affect your score since guessing is $$$-\frac{1}{3}$$$ and a correct answer is $$$1$$$ so out of $$$4$$$ items u will average $$$0$$$ points if you guessed. I'm not entirely sure about this one, but I think that this is more or less how it works.

As for rating, there's only been $$$1$$$ study on cf rating vs $$$IQ$$$ and it used a bad $$$IQ$$$ test but it found that a $$$115$$$ $$$IQ$$$ corresponds to a rating of just around $$$1600$$$, but this comes with some caveats:

• this was at a point (or perhaps just after the point) where rating started at $$$1500$$$ so a $$$1600$$$ back then is not equal to a $$$1600$$$ now, especially considering that the avg skill has gone up since then.
• the $$$IQ$$$ test they used was bad. idk why they tried to downplay an $$$r = .45$$$ correlation, especially on such a meh test, like $$$r = .45$$$ is already much higher than the correlation between chess and $$$IQ$$$. imagine if they used a good test.
• The test didn't take into account practice, so we don't know how much more the people in that sample there could've stood to improve.
• the sample seems to be higher-ability than the average cf participant, just by looking at the graphs. who knows what this means.

So, I would say that you could improve to the $$$1400-1600$$$ range if you made it a goal to practice every day and gave it some time.

Also thanks for taking the test, hardly anyone takes the tests I recommend, even tho it is an objectively positive experience to take such a high-quality test.

back at it huh

I am starting to question my cognitive ability

I think that you should take the $$$AGCT$$$ on cognitivemetrics.com and use code $$$FREJARD$$$ at the end to avoid paying any money. The people who revived that test, they aren't the most honest people, but they do know their stuff, so it is an accurate measure of your $$$IQ$$$. Then you won't need to question your cognitive ability anymore.

that horse's name? your mother

https://mirror.codeforces.com/contest/2057/problem/D

I feel like rn those most affected by cheating are those in the rating range of $$$1800-2100$$$ or so since the top of div $$$2$$$ is absolutely littered with cheaters, so if you were to get like $$$100^{th}$$$ place w/o cheaters, it might actually become $$$250^{th}$$$ or so. So I think that it will probably take longer than $$$2$$$ months. But I wish you luck.

there's something about online chess that just brings out the worst in people. one time I was playing against someone and I was losing and they started spamming the chat with kissy face emojis and I had no choice but to break my computer monitor. online chess is just too intense for most people I think.

I think you mean $$$KMP$$$

I think that $$$D$$$ and $$$E$$$ are nice, even tho I couldn't solve either, but they were fun to think about. Good job guys. Also, I think that $$$D$$$ and $$$E$$$ would definitely have like $$$\le 50\%$$$ of their solves if there were no cheaters. And $$$F$$$ having $$$120+$$$ trusted solves is crazy. cf contests would still be relatively clean if all these obvious cheaters were removed, hell probably $$$60-70$$$ people in the trusted top $$$100$$$ would get removed. If a few trusted active people could just ban whomever they wanted to, and they really cared about removing all the cheaters, they'd clean the standings up, no doubt. Also, take someone with $$$\le 1400$$$ rating (including unrated people) in the top $$$100$$$. The probability that they are a cheater is much greater than the probability that they are a legit participant, so people should just ban them and then they can appeal, and when the cheaters appeal, their responses will be chat GPT and obvious, so it'd be a lot less work.

oh, I can tell

it cleared you, dw

Dang I remember when that guy used to do crazy skits on youtube, back then you could pretty much make any video and they wouldn't censor it. I do wonder what happened to that site. Anyway, I'm not saying that you cheated $$$100\%$$$, but it seems a bit odd to me that you'd go from $$$13000^{th}$$$ in a div $$$3$$$ to $$$60^{th}$$$ in a div $$$2$$$ in just $$$2$$$ months.

yes, go to f"https://mirror.codeforces.com/problemset/problem/{number}/{letter}" like https://mirror.codeforces.com/problemset/problem/1000/A

I will take that bet if you're still up for it

how

fun contest, also did anyone else try printing WU for $$$B$$$

oh shit this reminds me of a leetcode problem https://leetcode.com/problems/minimum-number-of-operations-to-make-all-array-elements-equal-to-1/description/

also I think that what you said should basically be it, if there's a $$$1$$$ then you're done, otherwise just find the smallest subarray that gives you a $$$1$$$ (if any)

btw you might be able to have the complexity be like $$$O(n \log n \log A)$$$ or something with a sparse table and sliding window to find the min subarray with a gcd of $$$1$$$. use the sparse table to efficiently calculate the $$$GCDs$$$ of some subarray, and then you can do a sliding window on the array, moving $$$r$$$ as long as the gcd of the current windows is $$$ \gt 1$$$. the problem comes when you have to move the $$$l$$$ forward, how do you recalculate the gcd? well you just use the sparse table in that case.

Would you say AI should not be banned for those contests either?

I think that google searching should be banned to eliminate the gray area. Or, instead of blacklisting $$$AI$$$, they should whitelist certain sites that are known to not have any $$$AI$$$ parts, like usaco guide and cp-algorithms.

It can be fun to use $$$AI$$$ if you are solving problems $$$AI$$$ can't one-shot, and also if the problems are more open-ended, and I believe that the April fools problems are more open-ended. Like if you have ever done ctf challenges, which have more of an open space than cf problems, using $$$AI$$$ there doesn't not require skill, and the $$$LLMs$$$ can't possibly give you the entire answer (or even close to it) cuz it's a much more intricate challenge than cf problems. So it doesn't take the challenge away from it.

But this all assumes that April fools problems have enough potential pathways so that an $$$LLM$$$ won't be able to come close to the answer. Looking at some of the past problems, this seems to be the case for a lot of the problems, but I might be wrong.

I must say I'm a bit taken aback by the seriousness of your reply, but I appreciate it. Anyway, I think that banning $$$AI$$$ like this for this round leaves a lot of gray area, since when you are googling things for these problems, a lot of the results are AI-generated nowadays. Also, as shanyikai pointed out, I guess it should be clarified.

What's the fun in making AI solve the problems?

if $$$AI$$$ cannot one-shot these problems (which I'm assuming it can't since they're weird problems, but maybe I am wrong), it could definitely be fun. But that's just my opinion.

It is, without a doubt, the least enjoyable part of April Fools for us to respond to clarification requests with funny responses.

sorry, but are we allowed to use $$$AI$$$ in this contest? cuz it seems like these contests encourage using outside resources, and if that is allowed, then it already introduces a lot of gray area cuz of google $$$AI$$$ overview and stuff.

overthinker

$$$2026$$$, btw in the future $$$AI$$$ will take over the contests

I guess it depends on the dictatorship

dang giving out money for online contests atp is crazy

yo tell him to turn his computer around

I think that whether or not it did that doesn't matter too much. in a few months it'll be able to $$$AK$$$ div $$$1$$$ s no problem. Also, it seems a bit risky to give $$$AI$$$ models access to the internet like that.

cf div 1 is eventually gonna look like leetcode rankings

if all code submissions are made easily downloadable by everyone we run into a totally different copyright/ model data training issue

how? I don't think anyone actually cares if their code is downloaded.

A few years ago I realized that whenever I was reading a paragraph or two that was talking about one specific thing, that specific thing being written in all caps (like $$$IQ$$$, $$$AI$$$, etc) and I looked at the entire few paragraphs without focusing on any specific word or line, all of the mentions of that specific thing would stand out. like the paragraph would look like

wwwwwwwwwwAIwAIwwwwww

wwwwAIwwwwwwwwwwAIwww

wwwwAIwwwwwwwwwwwwwwwAI

wwwwwwwwwwwwwwAIwwwwww

and I thought it was pretty cool that you could "see" the main idea for these specific blocks of text without actually reading anything so now I try to emphasize words/acronyms that are all caps (and numbers too, but those are math things).

if $$$AI$$$ is so good at assisting cheaters, then maybe it could help with banning cheaters. if you look at most cheaters' graphs, they look something like this: Akshat_Agg. and if $$$AI$$$ can solve $$$3000$$$-rated problems, surely it can differentiate between cheaters and honest users at a somewhat decent level.

understanding it was the challenge imo

If it makes you feel better, no one thinks that India is charming on paper. Also, I feel like cf definitely has pretty annoying wa/tle/mle indicators. The $$$AC$$$ is definitely nice, but the failure messages (and coloring and font) are pretty boring, which I guess is what they should be, but they get annoying after some time. But maybe that is just from associating them with $$$WA$$$, though. Btw this was enjoyable to read, I think these things are nicer when written more like a short story vs just a recount of the events.

yeah I remember their round got mass downvoted just cuz of that, and there were all sorts of claims that they leaked the problems. pretty sad that it is normalized now, I guess div 2s will be like that from here on out, unless something biblical happens

yeah just a few months ago it would be rare to see a <= expert in the top $$$ \lt 200$$$ of a div 1 + 2, but now they are very common, probably making up like 1/8 of the users there or something.

at least for now they are easy to identify since their rating graphs look like this: Akshat_Agg.

yeah but you don't need to be aiming for that to make a lot of comments

huh interesting, I made my cf account almost exactly $$$1000$$$ days ago, which means that I would only have to have made $$$1.7$$$ comments a day to make all those comments. I'm kind of surprised no one else has done more than that in the past $$$4$$$ years.

$$$2$$$ dollars for that would actually not be bad here. I would prefer two actual items instead of one of the pies they give out (which are good but small), but I am assuming that the price there is much lower than it would be here since China is poor. All of their prices have just gone up a crazy amount in the past $$$10$$$ years or so, like outpacing inflation by a lot. I remember when they used to have the dollar menu, but now a cheeseburger will run you like $$$3$$$ dollars. And that's just for the cheeseburgers. Bigger items like the chicken sandwiches are approaching $$$6$$$ dollars. Like it shouldn't be normal to go to McDonalds with a group of people and spend $$$50$$$ dollars. It's really a disgrace what has happened.

I don't know if it's the same one, but the new one here in America is also really disappointing. It's pretty much a normal burger, nothing really new about it, but it costs $$$12$$$ dollars. $$$12$$$ dollars for a burger. I don't know who they think they are selling to.

Hopefully, but I believe that it will only get worse since now they can get rid of their Indian accents with AI. Also, if AI really does end up taking a lot of programming jobs, a lot of Indians will be out of legitimate jobs, and some of them will resort to fraud.

awesome, can you please also ban Coder-Ramesh while you're at it?

congratulations broski

dang this was that guy from the post

I think it's because of two things. The first one is that some people just like to cheat. You can talk to them and try to explain to them why it's not cool to cheat (and how it's not even beneficial to them, usually) but it's in one ear and out the other for them. The second is that, since AI is so good now, the cheaters get concentrated at the top. So even if there are only $$$100$$$ cheaters, you will maybe see like $$$50$$$ of them in the top $$$100$$$.

Luckily, at least for now, cheaters' rating graphs usually look unrealistic, for example like this:

Ginge

damn that thing is ugly

Coder-Ramesh

In my opinion, $$$500$$$ spread over $$$5$$$ years (2 a week, on average) is definitely not very consistent, especially since a lot of those were probably beginner problems, like leetcode easy-medium or so. I don't want to say that this post was unwarranted, cuz struggling with easy problems is not the most fun thing, but I think that you should at least try like $$$3$$$ months of solid practice before thinking this way. Even if you don't improve after a few months, at least you will have your answer.

For $$$IQ$$$ tests, there's this site: https://cognitivemetrics.com/ that is really hit or miss. They have some great tests there, but sometimes they do a bait and switch on the "free" tests, where they try to charge you like $$$20$$$ dollars after you have already taken it. That's pretty much as scummy as you can get without being outright fraudulent. And all of those tests used to be free, too, well except for the ones that they made themselves. The best test you can take there in under and hour is the $$$AGCT$$$, but I'm pretty sure they're gonna try to charge you for that one. And trust me, it's a good test, but it's not worth giving money to those people. Anyway, I'm pretty sure that all of these subtests https://cognitivemetrics.com/test/CORE/take (scroll down) are free still — you just need to have a working email. If you are not a native english speaker, the best ones to take there are probably quantitative knowledge, arithmetic, figure weights, and matrix reasoning. Out of the nonverbal tests, those tend to have the highest correlations with general intelligence. Block counting is fun too, but I'm not sure how good of a subtest it is. Anyway, the $$$IQ$$$ scores you receive are mean $$$10$$$ sd $$$3$$$, and just be aware that the raw score -> $$$IQ$$$ score conversions were created by the people who made the site, so they (the conversions) are probably decent but not great.

Hey! I saw the previous reply and while it's a solid baseline, it actually misses out on some high-level "magic" used in competitive programming and number theory to break that O(n) barrier. If you're looking for 10 9 specifically, you're right on the edge where O(n) might TLE (Time Limit Exceeded), but sub-linear approaches absolutely exist.

Here is the deep dive into how we actually go sub-linear:

1. The O( n

​ logn) Polynomial Approach When the modulus m is a prime p, we don't actually have to multiply every number. We can treat the factorial as a product of values of a polynomial.

Imagine we split n into B blocks, where B≈ n

​ . We define a polynomial:

P(x)=(x+1)(x+2)…(x+B)

Now, if we evaluate this polynomial at x=0,B,2B,…,(B−1)B, we get the product of each block. For example:

P(0)=1⋅2⋅⋯⋅B

P(B)=(B+1)⋅(B+2)⋅⋯⋅2B

By using Fast Multipoint Evaluation (which uses the Fast Fourier Transform or FFT), we can evaluate a degree-B polynomial at B different points in O(Blog 2 B) time. Since B= n

​ , your total complexity becomes roughly O( n

​ log 2 n). For n=10 9 ,
n

​ is only about 31,622, which is well within the limits for a 1-second execution time!

1. When n is close to the Modulus (Wilson's Theorem) If your n is very large but also very close to a prime modulus p (specifically when p−n is small), you can use a "backward" approach. Wilson's Theorem states that:

(p−1)!≡−1(modp)

Since (p−1)!=n!⋅(n+1)⋅(n+2)…(p−1), you can find n! by calculating the product of the small range from (n+1) to (p−1) and then finding its modular inverse. This turns an O(n) problem into an O(p−n) problem.

1. The Prime Power "Sieving" Trick If you only need to find the exponent of a prime p in n! (like asking how many trailing zeros are in 10 9 !), you use Legendre's Formula:

E p ​ (n!)= k=1 ∑ ∞ ​ ⌊ p k

n ​ ⌋

This is O(log p ​ n), which is incredibly fast—practically instantaneous for 10 9 .

Summary Table of Approaches Scenario Complexity Technique General n<10 8 O(n) Standard Iteration Prime m, n≈10 9 O( n

​ logn) FFT + Multipoint Evaluation n close to m O(m−n) Wilson's Theorem + Modular Inverse n≥m O(1) Result is 0(modm) So, while the "naive" approach is linear, the mathematical reality is that we can squeeze a lot of performance out of the structure of factorials. If you're dealing with a prime modulus, that
n

​ jump is your best friend.

Would you like to see a breakdown of how the Chinese Remainder Theorem allows us to apply these tricks even when the modulus isn't prime?

Imo, you have a good attitude, and I think that it takes a lot of humility to admit that you might not have the ability to do something. Especially something like this, cuz most people like to think of themselves as smart compared to other people (whether they like to admit it or not). Most people, like the people on r/leetcode, just blame the problems or the interview process and say they're stupid. That's just a terrible attitude.

But I must say that usually people who write these posts haven't done that much practice. You should just give us an idea of how many cf problems you've solved so far. $$$100$$$? $$$1000$$$? Imo, if it's $$$ \lt 300$$$, especially spread over $$$5$$$ years, you should practice a bit more and then come back after like a decent amount of continuous practice.

I think that div 2 $$$B$$$ is, on average, the most $$$IQ$$$-like problem out of all the problems out there (well, just div 2 problems actually, idk about div 1 problems). At least in my experience, div 2 $$$C-E$$$ are a lot of times recycled ideas, and if you do enough of those, you will start to see that most of them aren't that unique. But div 2 $$$B$$$ is always pretty unique.

Btw, have you ever taken an $$$IQ$$$ test? It might be a good idea cuz then you can know what to expect from continued practice. I can link you a few free ones if you would like.

try $$$m=73,\,s = 132$$$

in binary:

$$$m = \,1001001$$$

$$$s = 10000100$$$

cuz poland is, ofc, the model country

all of the things you mentioned are either not real or demons, so trusting them would be a horrible idea in general

I do think that it'd be effective, and sure, they could have the resources to do it. But imo it's not worth it. There is no way that screencasts are a 'light version of proctoring'. Imo, a light version of proctoring is like what leetcode does, where they log your keystrokes when you're writing your solution on the site. Screencasts are pretty invasive compared to that. And I think that they go against the spirit of online competitions. But I'm not sure, online contests (or at least honest standing/ratings) might be hopeless without things like that.

bro you forgot to take a GPT comment out of one of ur submissions (rank 93, Q2). hopefully leetcode bans you for real this time (and cf too)

silver is past $$$100$$$ now tho. $$$88$$$ to $$$100$$$ in $$$10$$$ days?

damn AI was too retarded to even understand my post

Sure, but imo the difference is that most of the admins (maybe all of them) just aren't too active / don't have the time for all that. The cf community has a lot of people who do have the time for that (and who might enjoy it). If cf could somehow give the community limited permission to ban people, I'm sure the community would set up a sophisticated process to identify and ban users. Idk how exactly the process would work, but I'm sure something decent would be created.

I don't know why Codeforces still doesn't require screencasts, at least for rounds with prizes.

I think that many people really would not prefer this, but even if it were 'the way forward', I don't think that cf has the resources to implement such a thing. In my opinion, that is why the community should play a big part in banning cheaters, cuz no big system like that is ever gonna get implemented by cf.

damn

I agree with the first sentence. The cf admins just don't have the time for that, which is fine. But I think that letting the community have some sort of say in who gets banned would actually help fix any slowness in the current process (if there is slowness), cuz it would add so much more motivation to identify cheaters. Currently, if the community identifies a cheater, they may or may not get banned. And if they do end up getting banned, it might take a while for the admins to get around to it. But if the community had the ability to ban users, any cheater would get banned instantly pretty much (after getting confirmed as a cheater ofc). Think about how many more people would contribute to finding cheaters just cuz there would be guaranteed results.

why not instead of making any 4-6 trusted community members just have the contest setters flag them?

I think that, ideally, these $$$4-6$$$ users (if such a thing were to happen) would not even really be making their own choices — they'd just be banning people based off of some hierarchical system like the current cheater database, where someone submits a report and then it gets reviewed by someone. It could be a very intricate system, but I think that the cf community is capable of creating such a thing. The $$$4-6$$$ people would just be the final decision, but they have to be trusted ofc so they don't just ban anyone.

I think the problem with relying on contest authors to flag users is that 1. there wouldn't be such a system in place, so the decisions wouldn't be as accurate, and 2. I would bet that not all contest authors want to do such a thing.

I really do think that it's a bottleneck. To demonstrate this, I've selected $$$5$$$ random users from macaquedev's cheater database. The current cheater database contains ~$$$3000$$$ users. Here are $$$5$$$ randomly-generated numbers between $$$1$$$ and $$$3000$$$: $$$886$$$ $$$2636$$$ $$$1729$$$ $$$596$$$ $$$2239$$$. On the corresponding lines of this file, these correspond to devyuvraj4873108011, soham_pal2005, mahmudrashik, BinaryPhoenix10, Quinos2003. Have any of them actually faced any consequence for cheating? I don't know, but I know that $$$5/5$$$ of them are not banned.

"jarvis, solve this problem but make all the variables 1-2 characters long"

reddit mod.. I mean Um_nik

nominated by me

System

nominated by me

Nyemot

nominated by me

imo it's not that bad of a username

first.

post nut clarity damn

That definitely seems to be the main factor for rate of improvement. I really think that there are only two big factors that contribute to one's rate of improvement, which are:

• $$$IQ$$$
• How early you started (like how people who are native English speakers pretty much always speak it better than nonnatives, but this effect is probably less pronounced in codeforces skill than it is in speaking any sort of language).

A small one might be the quality of practice, but that doesn't seem to be too important, and I get the impression that very experienced users also don't think it's incredibly important, as long as you're not literally wasting time on $$$800$$$ s.

But I think it is important to point out though that not all mind games (chess, competitive programming, go) correlate so highly with $$$IQ$$$. It seems that the general wisdom is that if you can play chess well, you are smart. But, in reality, chess has a very weak correlation with general intelligence, especially in ranked players (around $$$r = .3$$$ for all players and like $$$r \le.2$$$ for ranked players). Imo, the reason for this weak correlation could be because more specific mental abilities (that aren't necessarily too related to general intelligence) play a larger role in chess skill than some would expect. And the reason why general intelligence plays a smaller role in ranked players than in unranked players is just because of Spearman's law of diminishing returns, and we can assume that something similar is in play for codeforces skill.

But I would be surprised if cf skill had a correlation below $$$r = .45$$$ with general intelligence (in the general cf population), just cuz cf involves a lot of math (and math subtests are some of the most g-loaded subtests out there, usually about as strong as vocab tests). Also, the one study done on cf vs $$$IQ$$$ found a correlation of $$$r \approx .43$$$. And I am almost certain that this underestimates the actual correlation in the general cf population by quite a bit because:

• It used a bad $$$IQ$$$ test, so assuming that general intelligence is the only common factor between the $$$IQ$$$ test and cf rating (which might be roughly true), the correlation would only go up if a better test were used.
• The average rating of those sampled is a bit higher than the average rating of a normal cf user. Because of Spearman's law of diminishing returns, this would also imply that the correlation is an underestimate.

So I would not be surprised if the correlation were as high as $$$r = .6$$$ (which would mean that general intelligence by itself would account for $$$36\%$$$ of the differences in cf skill).

how'd u manage to capture the first element of

l1 = []
l1.append(l1)
print(l1)

but also good job on apologizing.

You are always bringing up chess lol, well maybe not always, but this is at least the second time. But tbh that has happened to me quite a few times, mostly on over-the-board chess. It seems like I play ~$$$500$$$ points below my online board rating when I do real life chess. Also thanks, but btw that was not in today's contest.

I think that it is because a lot of people solved $$$D$$$, which had more points than $$$C$$$ but was easier I guess. Also, you solved $$$B$$$ and $$$C$$$ fairly late, so that puts you at the bottom (more or less) of people who solved either $$$C$$$ or $$$D$$$ (or both). btw you can get this extension if you would like to see ur predicted rating change.

first.

December is the perfect time to wrap up the year

btw it's the only time to wrap up the year

I've seen some studies, and their main advantage is processing speed in general, as we've discussed.

I'm not gonna doubt you that East Asians on average have higher processing speeds than whites, and maybe that is even the $$$WAIS$$$ index where they outperform whites the most. I'm not sure, and I don't think it matters that much.

East Asians have been shown to outperform whites in highly g-loaded tests of nonverbal and mathematical thinking (Raven's progressive matrices (which, okay, isn't that highly g-loaded), older versions of $$$SAT$$$ math). These tests have very lax time limits, so it's hard to make an argument that processing speed plays a significant role in the scores on these tests. I don't even think some versions of the progressive matrices are timed, but East Asians still do better than whites. If you look at the average PISA math scores, you find that East Asians do the best. The evidence points towards East Asians being a good deal better at math than whites, on average.

If you would argue that their higher scores on these tests don't mean they are better, I would like to hear it.

The dominance of Europeans (that persists even today, despite the globalization of academia), in fields like math, physics, and theoretical computer science practically refutes that idea.

I'm not sure how true this is, but anyway something like this would not necessarily be due to Asians' lack of mathematical ability. But I do see your general point here, and I think that that is part of the mystery. I don't think the answer lies in the fact that they are actually lower than whites in mathematical ability, though, since that would go against pretty much all of the relevant $$$IQ$$$ test data out there.

Also, I think that chess is a bad example of something that requires ingenuity, since it is weakly correlated with general intelligence at the high levels, and those who start young have a massive advantage over those who don't. Plus, chess isn't really that big in East Asian countries.

Well it wouldn't always be the case that the highest-$$$IQ$$$ candidate gets the job; the $$$IQ$$$ tests would just replace the leetcode interviews. I think that this would be an improvement for everyone involved.

IQ tests overemphasize processing speed

Some do. The ones that do usually don't have great correlations with general intelligence, though. I wouldn't say that the Wonderlic overemphasizes processing speed, though, to a point where it'd decrease its g-loading. But also, the Wonderlic is not on the level of professional IQ tests, so you can't hold it to the same standard. Still, its g-loading is undoubtedly higher than that of a leetcode test.

several East Asian nations might stand out at the top, but have they been the most innovative in the modern era? No.

That's a good point, and I don't know what the problem with East Asians is (I have thought about it a bit). I think that some of it is due to the fact that their $$$IQ$$$ advantage is almost entirely because of their nonverbal/mathematical advantage. Their verbal scores are around those of whites, if not slightly lower. Verbal ability seems to be more important than mathematical ability in most cases.

But if you look at any major math/computer Olympiad, they dominate. So, regardless of whether you use $$$IQ$$$ tests or leetcode problems to filter candidates, the East Asians will get through, so if you were arguing that they would get through the $$$IQ$$$ barrier but not necessarily the leetcode barrier cuz of their supposed lack of ingenuity, I'd have to disagree.

Definitely not the second one. It wouldn't be as fun without rating. Even leetcode, which isn't nearly as rating-focused, isn't the same ever since AI got good enough to AK every contest. A whole new set of people that just appeared in the past year have taken the top $$$100$$$ (like jojo_007), and now the contests just aren't as enjoyable anymore. I remember a few weeks ago they actually had a problem that the AIs couldn't solve, and the leaderboard looked like it did in $$$2023$$$. None of the new people solved it, and leetcode still didn't ban them.

I think a better solution to the problem would be to get the big tech companies to stop caring about competitive programming. The only reason why there are so many cheaters is because the big tech companies care. All of the cheaters are either children, who get caught easily, or folks doing it for job opportunities. Certainly there are honest people that come from this group, but it is true that most of the dishonest people are in this group.

My solution is this: big tech companies should give $$$IQ$$$ tests to their candidates. This would:

• Save candidates' time. candidates wouldn't have to waste dozens of hours grinding hundreds of leetcode problems to have a shot at big companies.

• Work as a better filter: the only reason why competitive programming problems are alright at filtering candidates is because there is some relationship between competitive programming skill and general intelligence. If you just give the candidates an $$$IQ$$$ test, you would immediately have a better filter cuz you have a better indication of general intelligence.

• Save time and resources for the company: a technical interview usually takes $$$30+$$$ minutes, and you constantly have to replace problems so they don't get leaked online. On the other hand, the Wonderlic, a decent $$$IQ$$$ test, takes $$$12$$$ minutes, and the companies don't have to worry about replacing problems since the Wonderlic company handles that. There are many more options for good $$$IQ$$$ tests.

• Save online competitive programming contests.

Is there even a downside?

In my opinion, cheaters are no excuse to put such restrictions on this site. Can you really imagine codeforces but you have to submit a government ID to get a real rating? That goes against the spirit of the site. Your points are kind of similar to the US government's argument for the "patriot" act and TSA after 9/11: because of the increased terrorist activity (or that was their scapegoat), they felt like they had to put more restrictions on their citizens. And of course, once those restrictions get put into place, they can never be taken away. So you will have to deal with TSA for your whole life, along with other government organizations that get created in the future due to similar arguments. To give you credit, I think that your argument is genuine, unlike the other ones.

Can you give some quick tips

Unfortunately, I don't really have any other than solve hard problems, but you can get that advice from anyone. If I were you, I'd be solving in the range of $$$1900-2100$$$ mainly. When you've done enough problems, a lot of problems at or below your rating just become about combining/altering tricks you've seen before.

ah there's no coming back from that except by actually doing it

the government said similar things before implementing the TSA

guy got downvoted for giving advice beyond the generic "solve more problems"

Don't tell me that in India interviewers ask for your cf rating xddd

I get the impression that they (the companies) do, since all these cheaters are always flexing their ratings on linkedin. Like if there is an Indian cheater exposed post, $$$60\%$$$ of the time the cheater posted their 'achievement' on linkedin.

I think the problem is that competitive programming is popular now mainly due to many companies using leetcode-esque problems in their interview process. So a lot of people who do competitive programming don't do it because it is enjoyable to them — they do it because it might help them in getting a job later. And since their goal is just to get a job (and not to get better at the skill) they are way more likely to cheat than people who just do it for the hell of it, because they actually don't respect the skill or the site at all. It's just a barrier to them. So if we somehow convince the big companies to not care about leetcode problem solving skills, the problem will be solved, and most of the Indian cheaters will go away.

I also think that it's a good thread.

By the way, how does general intelligence affect thinking skills?

Well that's a very hard question, and I don't think anyone knows the answer, at least for codeforces thinking skill. There are surprisingly few studies on $$$IQ$$$ vs competitive math/programming skill.

First of all, most people don't know the definition of general intelligence, so just so we're on the same page, I will say it here. The general intelligence factor (or g factor) is basically a statistical factor (or underlying variable that can't be measured) that explains why some people will, on average, do better than others on pretty much every cognitive test in existence.

Like if you give someone a language test and they do really well on it, you'd expect them to do well on a math test too, even though, on the surface, there really isn't much in common between the language test and the math test. If you give someone a reaction time test and they do well (say, over-average) on it, well you can say that they are more likely than not to do well on pretty much every other mental test out there. You can argue that maybe doing well on tests isn't exactly the same as being 'smart', but the factor that accounts for this is called general intelligence.

Since codeforces can be considered a cognitive test, we can say that, given that two people know how to code but they don't have any competitive programming experience, the more intelligent one is more likely than not to do better than the less intelligent one. Okay, you probably could've figured that out by yourself. But, since general intelligence is so all-encompassing, this also applies to two people with the same amount of experience at any level of experience.

It's also important to note that just because general intelligence plays less of a role in higher-skilled contestants doesn't mean it plays less of a role in contestants with more experience.

I suspect that the skill gap between two people with differing $$$IQ$$$s widens rather than shrinks as the experience level goes up. Imagine someone who is like $$$70\,IQ$$$ — they might really have a tough time learning how to code, if they could learn at all. Their rating is basically gonna plateau very quickly at a really low level. Now imagine someone with $$$150+$$$ $$$IQ$$$ — they might reach $$$LGM$$$ with enough practice, but that would still take a lot of practice. The gap between the $$$70$$$-$$$IQ$$$er and the $$$150$$$-$$$IQ$$$er pretty much only increases, and I don't see why this would change for any pair of $$$IQ$$$ scores.

Also, if one's rating (output) vs time spent (input) could be a function, it would more or less be an increasing function but with a decreasing derivative, maybe like $$$y = IQ \cdot \sqrt{x}$$$. This would mean that, not only is someone with higher $$$IQ$$$ and the same level of experience gonna do better than you, but as you gain more and more experience (and they do too) it will take more and more additional time for you to close the gap, if they were to just stop practicing. So, to answer your question, I would say both. I would be surprised if it weren't both.

Since it's relevant, I'd like to also add this graph (scroll down a little bit to problems solved vs rating as a percentile) https://carnegiemellon.shorthandstories.com/competitive-programming-talent-vs-tenacity/index.html that kind of shows this widening, even with all of the interfering factors.

Btw, you say you're of average intelligence, but why don't you actually find out for yourself? I would really appreciate it if you tried a few subtests from https://cognitivemetrics.com/test/CORE this test (ideally, Quantitative Knowledge, Arithmetic, Figure Weights, Antonyms, Information: all 5 of those would yield a pretty accurate estimate of general intelligence (the items are good, but I'm not so sure about the norms, but they seem alright), but to be fair since I'm assuming English is not your first language, antonyms might be deflated for you).

You don't have to pay, unless the mods there made it so you actually have to pay now. I wouldn't be surprised if they did that, since some of them have done much worse things wrt scamming people. Everyone will eventually face judgement for what they have done. But the test seems alright. It will probably say you will have to pay but the charge will be $$$0.00$$$ and you just put in your email and get your score. Anyway, you don't have to take it but I think you should figure out if you are actually around $$$100\,IQ$$$ since you say it so much.

leetcode really is a cesspool now. they don't even ban obvious cheaters who put things like x = 1; x = x + x; in their code to look 'more real' well to be fair if you don't care about your rank the contests are still nice

Basically, what I was trying to say is that, because of Spearman's law of diminishing returns (higher-skilled persons rely less on their general ability (g) to solve tasks), general intelligence most likely plays less of a role in the skill of higher-rated users than it does in the skill of lower-rated users.

I think that you have a pretty good breakdown of competitive programming skill, and I'm not exactly sure how it is at 2500+ rating, but from what I've seen, "thinking skills" matter more in solving those problems than any sort of knowledge or implementation skills. So I actually agree with you. And it is true that competitive programming "thinking skills" or "problem-solving skills" are not close to the same thing as general intelligence, but they are definitely influenced by general intelligence.

Arpa did use that word, but he talks about improving it by practicing AtCoder and JOI in the very next sentence.

I guess that my problem is that it wasn't exactly clear what he meant by intelligence. Cuz somewhere in the video, he said something along the lines of "if you're intelligent, thank your parents" which would suggest that he was referring to something closer to general intelligence (which is largely heritable and can't really be improved) than codeforces thinking skills, which can definitely be improved to an extent.

I think the only way he could be consistent in his usage of intelligence is if he believes that one's baseline intelligence comes from their parents, but they can (possibly significantly) improve it by solving a lot of codeforces problems.

I think the best course of action is for cf admins to just use the community-made list and ban everyone there. The community members have much more time and incentive to ban cheaters than the cf admins, and if the list is managed correctly, I think that cf could ban most cheaters.

Arpa this one's for you

I feel like people think you're gonna publish it before the contest, which might be why you got downvoted. I clicked on the link and I think that you are actually a fairly good public speaker — I wasn't bored while I listened to the video on the homepage. But I think that you said that you're "not intelligent" too much. If you actually feel that way and you think mentioning it would add to your lecture, I think you should say it at most once.

Anyway, you said that past the rating of $$$2500$$$, the only thing that matters is intelligence. Your reasoning was that everyone at that level is perfect in knowledge and implementation, so intelligence is the only thing that matters then. But the reverse of this is most likely true: intelligence matters more at the lower levels and less at the higher levels. This is because the general intelligence factor is less predictive of skills, abilities, test scores in higher skilled/higher ability populations.

This is known as Spearman's law of diminishing returns, and it applies to $$$IQ$$$ tests themselves, as $$$IQ$$$ tests aren't perfect measures of intelligence (so someone who scored, say, $$$130$$$ on a test is more likely to be further away from their score in terms of "actual intelligence" than someone who scored $$$100$$$). But just because intelligence doesn't play as big of a role at that rating doesn't mean that mutable factors make up for it. So this doesn't necessarily mean that it's easier to change your rating at $$$2500$$$ than at $$$1500$$$, all else being equal.

Is the quote in problem $$$E - Lust$$$ a reference to the story of Daniel and the two elders (Daniel $$$13$$$)?

This seems like it could be a good post. Something that I found interesting is that, in order to solve the knight's tour problem on some rectangular board, you can just move the knight to a square with the least possible number of legal moves. And that works in $$$99\%$$$ of cases or something.

I also enjoyed learning about heavy-light and centroid decomposition, but I haven't seen any contest problem where you use these.

First.

Programming in the programming contest?

First.

broski is larping as System

honestly, these submission times seem just slow enough for this to not be automated. I really do wonder if he spent a week of his life just nonstop submitting code. Can you see if he had like any 8-10 hour breaks between submissions?

first.

By the way, I was sure that there was some sort of pattern in the problem names, but I could not figure it out. Maybe there is, if there is I just don't see it. But I do think that the name of C. Binary Wine does not fit in with the other names.

First of all, all of the names except for Binary Wine and Arctic Acquisition afaik stand for common competitive programming things when said forward or in reverse.

Same Difference = Data Structures

Tab Closing = Time Complexity

Cyclic Merging = Candidate Master

Marble Council = ^

Binary Wine = ???

Path Split = Shortest Path

Rainbow Branch = Regular Bracket (sequence)

Arctic Acquisition = Alcoholics Anonymous..?

So from here it looks like Arctic Acquisition and Binary Wine don't belong. However, we can insert the common beginning vowel in Arctic Acquisition into the middle of the acronyms of the other titles (and possibly reverse the result to get these):

SAD, CAT, CAM, MAC, SAP, BAR

but then for Binary Wine neither BAW or WAB is a word.

$$$A$$$ is like the situation where you and your friend are driving somewhere and you both estimate how long it will take you to get there and whoever gets closer wins, and you say something like $$$30$$$ minutes then your friend always says either $$$29$$$ or $$$31$$$ minutes. Very cool problem.