Analyzing how good O1-Mini actually is I would like to thank [user:redpanda,2024-09-13] and [user:qmk,2024-09-13] for their great help in writing and reviewing this blog. They are also the users who queried O1-mini for all the following problems. We tried O1-mini on several problems, from a variety of sources. Let's list the results first. **Note** : - Some of the WA verdicts here actually means that the AI just "stopped thinking" which means the AI thought for a long enough time without any useable results so it ran into an error. - All ratings mentioned are Codeforces ratings, the Atcoder ratings have been converted to codeforces rating. To measure the approximate codeforces rating of the atcoder problems mentioned here, you can use https://kenkoooo.com/atcoder/#/table/ + https://silverfoxxxy.github.io/rating-converter. <h4> D2ABs </h4> - [problem:1762B] [<a class="rated-user user-gray" title="Gray">1100</a>] <a class="rated-user user-green" title="Green AC">AC</a> - [problem:1998B] [<a class="rated-...

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Codeforces Round #616 Editorial Hello everyone, this is the editorial for [contest:1290] and [contest:1291]! Along with the solution to each problem, we will have the theme and easter egg solution as well! I hope you all enjoyed our problems ( ´ ▽ ` )b [problem:1291A] Author: [user:265918,2020-02-02] <spoiler summary="Tutorial"> [tutorial:1291A] </spoiler> <spoiler summary="Implementation"> ~~~~~ #include <bits/stdc++.h> using namespace std; int main() { ios::sync_with_stdio(false); cin.tie(nullptr); int t; cin >> t; while (t--) { int n; cin >> n; string s; cin >> s; int odd = 0; for (char c : s) if ((c - '0') & 1) odd++; if (odd <= 1) { cout << "-1\n"; continue; } int cnt = 0; for (char c : s) { if ((c - '0') & 1) { cout << c; cnt++; } if (cnt == 2) break; } cout << '\n'; } return 0; } ~~~~~ </spoiler> [problem:1291B] Author: [user:hugopm,2020-02-02...

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On designing a Codeforces shirt I heard about the Codeforces shirt design the day before the deadline, and I looked at the designs and they were almost all memes. I thought of making a serious design, since I am not good at memes. (I am also not good at comp prog.) Most programming shirts that I liked have nice abstract patterns based on algorithms, like the [Yandex.Algorithm 2015 shirt](http://mirror.codeforces.com/blog/entry/44549?#comment-293712). So I wanted to add a bunch of cool diagrams of algorithms. And I decided to use black, because, well, black is nice. I came up with the design of overlaying algorithms in the Codeforces logo, but I could not draw enough different diagrams, so I used three components. You can see the whole design here: #### Overall  I was inspired by the typography of [Material Design](https://material.io/), as well as the [old Google Design](https://web.archive.org/web/20160207175056/https://design.google.com/). So I used [Roboto Mono](https://fo...

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On Atcoder Beginner Contest 272F -- Two Strings Please note that this blog is a review of [this problem](https://atcoder.jp/contests/abc272/tasks/abc272_f). It is not novel enough to be an editorial. This problem may not be difficult for those people who are beyond purple, but very difficult for me. To be more self-contained, I copy the problem here: Problem Statement: You are given strings $S$ and $T$ of length $n$ each, consisting of lowercase English letters. For a string $X$ and an integer $i$, let $f(X,i)$ be the string obtained by performing on $X$ the following operation $i$ times: Remove the first character of $X$ and append the same character to the end of $X$. Find the number of integer pairs $(i,j)$ satisfying $0≤i,j≤n−1$ such that $f(S,i) \leq f(T,j)$ lexicographically. For example, when $n=3$, $S=$"adb", $T=$"cab", there are 4 pairs: (1)$i=j=0$, "adb" $\leq$ "cab"; (2)$i=2, j=0$, "bad" $\leq$ "cab"; (3)$i=0, j=2$, "adb" $\leq$ "bca"; (4)$i=j=2$, "bad" $\leq$ "bca". You can find more test cases here:...

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Need An improvement for my solution [H. Asterism Stream, Berlekamp-Massey] I was using the [Berlekamp-Massey (BM)](https://en.wikipedia.org/wiki/Berlekamp%E2%80%93Massey_algorithm) algo for [yesterday's H](https://mirror.codeforces.com/contest/1864/problem/H), but my sol worked too slow. Here is my idea: (1) Divide $[1, n]$ into scales. Let $S(scale)$ be the scale $scale$, which is $S(scale)$ is $\\{x | x \times scale \geq n, x \times scale/2 < n\\}$. For example, if $n=7$, scale $1$ is $[7, 7]$, scale $2$ is $[4, 6]$, scale $4$ is $[2, 3]$, scale $8$ is $[1, 1]$. It is guaranteed that $scale$ is a power of $2$ in my sol. (2)Fetch $O(log scale)$ consecutive items for each scale using the matrix fast power algorithm. The matrix is constructed in step (3) from the last scale. (3)Using the BM algorithm to build a recurrence of length $O(log\,scale)$ and a recurrence matrix $M \in \mathbb{Z}/p\mathbb{Z}^{O(log\,scale) \times O(log\,scale)}$. I mean for each scale we fetch some items $I$, get a recurrence using the BM algorithm, and construct a recurrence m...

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Standings Converter Всем нравятся тренировки без мониторов? А даже если и с мониторами, то с кривыми логами сабмитов, автоматически сгенерированными Codeforces? Я наконец-то выложил давно написанную утилитку для конвертации лога сабмитов. Называется она [Standings Converter](https://github.com/alexeydergunov/standings-converter). На данный момент поддерживается только чтение из Ejudge-формата и запись в Testsys-формат, потому что это то направление конвертации, что нам приходится использовать каждые полгода, чтобы добавить очередной самарский контест в тренировки Codeforces. Но вы можете добавлять свои Parser-ы и Outputter-ы :) **Q:** Я сгенерировал лог Testsys с помощью этой утилиты, как теперь его добавить в тренировку? **A:** Назвать этот файл contest.dat, зайти по FTP в папку нужной тренировки, скопировать contest.dat в папку sandbox, а потом нажать в интерфейсе тренировки кнопку Обновить соревнование. **Q:** У меня не установлен Maven и я не использую Java!!!11111 **A:** Пиши свой парс...

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A2SV G5 — Fun Contest Editorial [Here](https://mirror.codeforces.com/contestInvitation/2039807e90cc28883ce38a29be36443281b1a5cd) is the link to the contest. #### [A. Photo Shoot](https://mirror.codeforces.com/gym/563686/problem/A) <spoiler summary = "Hint"> What do we all say together when Dagim is about to take our picture? </spoiler> <spoiler summary = "Solution"> A2SV </spoiler> <spoiler summary="Code"> ```python3 print("A2SV") ``` </spoiler> #### [B. Is It Special?](https://mirror.codeforces.com/gym/563686/problem/B) <spoiler summary = "Hint"> What day is special for the Contest Squad? </spoiler> <spoiler summary = "Solution"> Saturday </spoiler> <spoiler summary="Code"> ```python3 T = int(input()) for _ in range(T): day = input() if day == "Sat": print("Yes") else: print("No") ``` </spoiler> #### [C. The Graph of G5](https://mirror.codeforces.com/gym/563686/problem/C) <spoiler summary = "Hint"> In every node input add 'G5' as a prefix. </spoiler> <spoiler ...

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Web service for defrost standings of competition — S4RiS StanD Good afternoon. Today I want to share with the public my little project (which was part of my thesis), service on the "defrost" the results of the competition format ACM ICPC &mdash; "System for Right Solutions Standings Dancing" (S4RiS StanD). Hosted on [github](https://github.com/OStrekalovsky/S4RiS-StanD). #### Introduction In 2011, my team is still held in the semifinals, where at the close I saw the live operation of such a system ITMO. The feeling was strong. But after analyzing the work and reviewing captured my video, I realized that it is possible to improve this implementation, make it open to and more modest, local competitions, the participants were able to watch in awe tabulation of results. It was chosen as part of my thesis was used already in one competition and received a logical extension. <p> [cut] </p> #### About the service and its features Service is just a web page with a core written in JS and requires no "server" scripts. Therefore, this service ...

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Let's face it, Polygon is horrible  Polygon is not world's greatest evil. Polygon doesn't even have a particular defect that makes it horrible. You can't say what's exactly wrong with Polygon. Polygon seems to work, it seems like every feature is supported, but if you touch it here it will fall apart, and if you touch it there a problem (pun not intended) will appear. Or not, depending on your luck. Polygon is like PHP. For those who haven't read the famous rant, I'll cite it for you: > I can't even say what's wrong with PHP, because-- okay. Imagine you have uh, a toolbox. A set of tools. Looks okay, standard stuff in there. > > You pull out a screwdriver, and you see it's one of those weird tri-headed things. Okay, well, that's not very useful to you, but you guess it comes in handy sometimes. > > You pull out the hammer, but to your dismay, it has the claw part on both sides. Still serviceable though, I mean, you can hit nails with the middle of the head holding it...

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Codeforces <-> AtCoder rating correlation plots and convertation — get your expected rank on the site you are new with! Hello, Codeforces! I'm new on AtCoder and was interested, what rating would I normally get there after participating in CodeForces rounds, and how does rating on these two sites correlate. Of course, there is a correlation ;) Link to some plots and dependencies: [Rating correlation plots](https://silverfoxxxy.github.io/rating-correlation) preview:  And now you can get a prediction for the site you are new to. Here is CodeForces <-> AtCoder rating converter: [Rating converter](https://silverfoxxxy.github.io/rating-converter) preview:  You can send any suggestions to this e-mail: ivan-belkov2@ya.ru

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Timezone in emails I am grateful the contest announcements have a link to the "timeanddate.com" converter. But it would be truly convenient to see my local time in the email itself instead of UTC. It would be based on a timezone setting in the user's codeforces profile. I would love to see **Attention! The round starts on _MyOwnTime_** Please consider this request. The email is inserting my username, so it is pulling one variable from the profile already. So hopefully, inserting a second one is not too hard. Thanks!

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The real problem nobody talks about As I'm sure you know, recently [user:sus,2021-09-08] managed to reach top contributors board. Some people may be excited &mdash; finally, a grey in top contributors. However, I think this is incredibly disappointing, since [user:sus,2021-09-08] has not actually contributed, at all, to the community. Let's take a look at his most recent blogs: September 7th, AFTERMATH --> This was completely upvote farming. He literally wrote a post congratulating himself on getting top contributor. At the end, he put some memes. If it's not clear, it's just a scheme to get more upvotes. September 6th, FINAL: TOP ANIME PROTAGONISTS OF CODEFORCES --> He basically just animed the profile photos of random highly rated programmers. He probably didn't do the anime himself and juts used some online anime converter. Not impressive, very lame. September 5th, HOW TO WRITE A GOOD BLOG --> Erm, also upvote farming on how to write a good blog. Useless, not even funny. September 2nd, WHERE ARE MY PANTS -...

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Huawei Labs Rus: Marathon match 1. Spatial Image Alignment If you are 14+ and want your ideas to be implemented in new technologies and products, which being used by 1/3 of global population, participate in our Marathon started recently https://it-edu.mipt.ru/en/huawei-codecraft-marathon Task can be downloaded after registration, see links below: John has a digital camera. He usually takes two photos, first photo is bad quality and blurred, second has good quality, but his hands shaked, and the second photo has moved compared to the first one. Help John to restore first(blurred) photo position, considering that the movement was in the same plane. Solution: We highly encourage participants to use neural network based approaches for solving this task. You can download 30 samples from checker in txt format. Data generation for neural network training is one of the main point in our task. Converter from/to graphic format is also part of this task. Registration can be done by captain. The team can consist from 1 to 3 team members: https:...

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Need a programmer Hi! I'd like to have a converter that is able to work with many file formats. I am willing to pay for it. What do I need? You must make one converter with many features, it somehow combine. I'm not a programmer, I do not know how to do it. Therefore, I appeal to you. This converter should be able to work as such these: - http://converton.net/pdf-to-doc/ - http://converton.net/djvu-to-doc/ - http://converton.net/epub-to-txt/ - http://converton.net/fb2-to-txt/ - http://converton.net/ogg-to-mp3/ - and other I hope I explained the problem clear. Thanks.

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