Code For Athoy — Contest for Saving a Life  ### Code For Athoy — Contest for Saving a Life Hi everyone, I hope you find this post in good health. A 17 years old brother(Athoy) of ours is **fighting with blood cancer** and his family is going through a stage where they can't bear the expense of his treatment anymore after managing 9 out of 12 chemotherapy. We are arranging an online programming contest nationwide for collecting funds for the treatment to continue. His family needs around 250,000tk(about 3,000$) for the next Chemotherapy and more in upcoming days. Currently, they're not being able to manage any reasonable help from other sources during this COVID-19 pandemic and selling out their last of the assets and belongings. We've been informed that Athoy needs three more chemotherapy till next year and completed the first installment for the next chemotherapy planned on 7-8th of June 2020. So, **for now we are plan...

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Contest Based on SUST Intra University Programming Contest 2019 Greetings good people of Codeforces. I hope you're having a great week. We are hosting a [contest](https://toph.co/c/sust-intra-2019-r) based on the problems of SUST Intra University Programming Contest 2019. The contest platform is [Toph](https://toph.co/). It was originally hosted on SUST's online judge [SourceCode](https://www.sustcseoj.com/). The contest will be held on [Friday, December 20, 2019 at 15:00 UTC+06](https://www.timeanddate.com/worldclock/fixedtime.html?msg=Contest+Based+on+SUST+Intra+University+Programming+Contest+2019&iso=20191220T09&ah=5). You will be given 12 problems in total and 5 hours to solve them. The contest will follow standard ICPC rules. The problem setters of the contest are [user:ovis96,2019-12-19], [user:YouKn0wWho,2019-12-19], [user:foyaz05,2019-12-19], [user:avivilla,2019-12-19], [user:shourov.sust,2019-12-19], [user:mk_shahriar,2019-12-19] and [user:Jubair_2147483647,2019-12-19]. To participate all you have to do is to create an accou...

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Invitation to Toph Criterion 2022 Round 17 Hello good people, I am delighted to invite you all to the [Toph Criterion 2022 Round 17](https://toph.co/c/criterion-2022-round-17)! To participate you have be registered on [Toph](https://toph.co/). Toph is a leading competitive programming platform in Bangladesh hosting various programming contests. The author of the contest are [user:upobir,2022-06-23], [user:shefin.cse16,2022-06-23], [user:rifatrraazz,2022-06-23], [user:adnan_toky,2022-06-23], [user:thisIsMorningstar,2022-06-23], [user:Short_Bit,2022-06-23], [user:Black_Be4rD,2022-06-23] and [user:TarifEzaz,2022-06-23]. Special thanks to [user:TarifEzaz,2022-06-23] for coordinating this contest and [user:hjr265,2022-06-23] for the **Toph** platform. You will be given **6-7** problems. The contest will follow **standard ICPC rules**. We've tried to create very engaging problems and robust datasets for this contest. We hope you will enjoy the problem set. Also, there will be an editorial shortly after the contes...

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Invitation to Tough Duo, April 2022 Hello, Codeforces community! We are thrilled to invite you to participate in the first-ever rated team contest of **Toph.co**: [Tough Duo, April 2022](https://toph.co/c/tough-duo-april-2022) on April 14, [02:00 PM BST](https://www.timeanddate.com/worldclock/fixedtime.html?msg=Tough+Duo%2C+April+2022&iso=20220414T14&p1=73&ah=3). To participate you will have to form a team of 2 members and be registered on [Toph](https://toph.co). You can create an account [here](https://toph.co/register). The contest is rated for all participants. There are also prizes for the students of Bangladeshi academic institutions: - 1st place: Toph goodies and 250 GB Portable SSD - 2nd and 3rd place: Toph goodies The authors of the contest are [user:upobir,2022-04-09], [user:shefin.cse16,2022-04-09], [user:adnan_toky,2022-04-09], [user:thisIsMorningstar,2022-04-09], [user:rifatrraazz,2022-04-09], [user:Black_Be4rD,2022-04-09], [user:Short_Bit,2022-04-09] , [user:TarifEzaz,2022-04-09] and [user:Joty...

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Invitation to the Replay of Bangladesh National High School Programming Contest 2021 Hi! We are thrilled to invite you to participate in the [Replay of National High School Programming Contest 2021](https://toph.co/c/replay-national-high-school-2021), **tomorrow**, **June $14$**, at [07:30 pm BST](https://www.timeanddate.com/worldclock/fixedtime.html?msg=Replay+of+National+High+School+Programming+Contest+2021&iso=20210614T1930&p1=73&ah=4). To participate all you have to do is to create an account on [Toph](https://toph.co/). You can register [here](https://toph.co/register). The authors of the contest are [user:upobir,2021-06-13], [user:_Ash__,2021-06-13], [user:YouKn0wWho,2021-06-13], [user:fsshakkhor,2021-06-13], [user:rebornplusplus,2021-06-13], [user:shefin.cse16,2021-06-13], [user:Hasinur_,2021-06-13], [user:jAckAL_1586,2021-06-13], [user:mainstring,2021-06-13], [user:Moshiur_,2021-06-13], [user:ishtupeed,2021-06-13], [user:Peregrine_Falcon,2021-06-13], [user:TarifEzaz,2021-06-13], [ihumaunkabir](https://toph.co/u/ihumaunkabir) and [shajia](https://toph.co/u...

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Criterion 2022 Round 19 Invitation Hello Codeforces! We are glad to invite everyone to participate in [Criterion 2022 Round 19](https://toph.co/c/criterion-2022-round-19), which will be held on [Friday, September 09, 2022 at 20:00(UTC+06:00)](https://www.timeanddate.com/worldclock/fixedtime.html?msg=Criterion+2022+Round+19&iso=20220909T20&p1=73&ah=2&am=30). You will be given **5 to 6 problems** and 2 hours and 30 minutes to solve them. The difficulty is expected to be similar to **Codeforces Div. 2 rounds**. The problems were invented and reviewed by [user:rebornplusplus,2022-09-04], [user:ishtupeed,2022-09-04], [user:curly_braces,2022-09-04], [user:Atondro_Wahid,2022-09-04] and [user:gola,2022-09-04]. Thanks to [user:TarifEzaz,2022-09-04] for his unconditional support and [user:hjr265,2022-09-04] for the best contest programming platform in Bangladesh. The contest will take place at [Toph](https://toph.co/). It will be [rated](https://help.toph.co/toph/rating-system/) for all the participants. This conte...

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Number of Solutions to a Linear Algebraic Equation ### **The Basic Problem** Suppose, we have a Linear Algebraic Equation, $X$$_1 + X_2 + X_3 = 5$. Here the values of $X_1, X_2$ and $X_3$ can be non-negative integers. We want to know in how many ways we can assign values to $X_1, X_2$ and $X_3$ so that the summation is 5. We can consider this problem as dividing 5 objects among 3 persons. And below are some possible ways to do it &mdash; <a href="https://imgbb.com/"><img src="https://image.ibb.co/e9FV2Q/Capture.jpg" alt="Capture" border="0"></a> Here by O the objects are being represented and | represents partition. As the objects are divided among 3 persons we need 2 partitions which is pretty clear from the partitioning instances above. We can finalize this problem as simple combinatorial problem of number of ways of arranging 7 objects where 5 are of first kind and the other 2 are of second kind. And the answer is $\dfrac{7!}{5! 2!}.$ So if we have n objects in total and we wan...

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Criterion 2020 Round 7 announcement Hello Codeforces! Tomorrow, on [September 11, 2020 at 15:00 BDT](https://www.timeanddate.com/worldclock/fixedtime.html?msg=Criterion+2020+Round+7&iso=20200911T15&p1=73&ah=2&am) we will be hosting [Criterion 2020 Round 7](https://toph.co/c/criterion-2020-round-7) on [Toph](https://toph.co). [Toph](https://toph.co) is a Bangladeshi contest programming platform. The contest will have 5 or 6 problems and will run for 2 hours 30 minutes. This contest is rated for all participants. You can register for the contest [here..](https://toph.co/c/criterion-2020-round-7) The problems were authored and reviewed by [user:De.Wilde,2020-09-10], [user:fire_tornado,2020-09-10], [user:Hasinur_,2020-09-10], [user:Atondro_Wahid,2020-09-10], [user:pranonraian,2020-09-10], [user:gola,2020-09-10] and me. Thanks to [user:TarifEzaz,2020-09-10] for his unconditional support and [user:hjr265,2020-09-10] for the best contest programming platform in Bangladesh. We're inviting you all to participate ...

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StopTheWar Programming Contest Hello Codeforces! Tomorrow, on [March 29th, 2018 at 13:00 UTC](https://www.timeanddate.com/worldclock/fixedtime.html?msg=%23StopTheWar+Programming+Contest&iso=20180329T19&p1=73&ah=5) we will host [#StopTheWar Programming Contest](https://toph.co/c/stop-the-war-programming-contest) in [Toph](https://toph.co/). Toph is a Bangladeshi contest platform. The theme of the contest is to protest against all the war of the world. There will be **13 problems** and you will have **5 hours** to solve them. The contest will be held on ACM ICPC rules. <b>Contest Link is [here](https://toph.co/c/stop-the-war-programming-contest).</b> The authors and testers of the problems are [user:-Morass-,2018-03-28], [user:mihassan,2018-03-28], [user:mk_Shahriar,2018-03-28], [user:whoisshihab,2018-03-28], [user:I_love_ProParThinkNot,2018-03-28], [user:Hasinur_,2018-03-28], [user:Mr_Emrul,2018-03-28], [user:shahidul_brur,2018-03-28], [user:ssavi,2018-03-28], [user:AhsanRomeo,2018-03-28] and [user...

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Online Mirror of NSTU ICE Fest Regional Programming Contest 2020 Hello Codeforces! Tomorrow, on [January 24th, 2020 at 03:00 UTC](https://www.timeanddate.com/worldclock/fixedtime.html?msg=Online+Mirror+of+NSTU+ICE+Fest+Regional+Programming+Contest+2020&iso=20200124T03&p1=%3A&ah=4) we will host [Online Mirror of NSTU ICE Fest Regional Programming Contest 2020](https://toph.co/c/mirror-nstu-ice-fest-regional-2020) in [Toph](https://toph.co/). Toph is a Bangladeshi contest platform. The onsite contest will also happen in the same time. There will be **10 problems** and you will have **4 hours** to solve them. The contest will be held on ACM ICPC rules. <b>Contest Link is [here](https://toph.co/c/mirror-nstu-ice-fest-regional-2020).</b> The authors and testers of the problems are [user:imAnik,2020-01-23], [user:halfblindprince,2020-01-23], [user:mainstring,2020-01-23], [user:I_love_ProParThinkNot,2020-01-23], [user:mazedrupok,2020-01-23], [user:baker_vai,2020-01-23], [user:pranto84,2020-01-23] and me [user:Mr_Emrul,2020-01-23]. We're ...

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Criterion 2020 Round 6 (Rated) Hello Community, We would like to invite you to the [Criterion 2020 Round 6](https://toph.co/c/criterion-2020-round-6). It is a rated round of Toph hosted once in a week. **Time:** [10th April 2020, 15:00(Bangladeshi Time)](https://www.timeanddate.com/worldclock/fixedtime.html?msg=Criterion+2020+Round+6+&iso=20200410T15&p1=73&ah=2&am=30) **Duration:** 2 hours 30 min **Contest Format:** [ACM ICPC Format](https://icpc.baylor.edu/regionals/rules) **Number of Problems:** 5-6 The problems are prepared by: [user:Hasnaine_,2020-04-09], [user:Dhruba10414,2020-04-09], [user:shefin.cse16,2020-04-09], [user:tanus_era,2020-04-09],[user:A_Modern_Desperado,2020-04-09], [user:Hasinur_,2020-04-09]. We would also like to thank [user:TarifEzaz,2020-04-09] and [user:hjr265,2020-04-09] for the beautiful platform and the opportunity. _**Happy Coding, see you in the scoreboard!**_ **UPD:** [Editorial](https://mirror.codeforces.com/blog/entry/75836) is here. ![ ](https://up...

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Tough Cubs' Contest, 8 Oct 2016, 1500 UTC We are pleased to announce that **[Toph](https://toph.ws)**, a Bangladeshi contest platform, is starting a bimonthly online programming contest for school and high school students, and anyone who is interested in getting started with sport programming! You can expect some relatively easy problems in this contest. The first contest of this series will take place on **[8 October, 2016 at 1500 UTC](http://www.timeanddate.com/worldclock/fixedtime.html?msg=Tough+Cubs%27+Contest%2C+October+2016&iso=20161008T15&p1=1440&ah=1&am=30)**. There will be four problems and 90 minutes to solve them. Scoring follows ACM-ICPC rules. Here's the registration link: **[Register](https://toph.ws/c/tough-cubs-contest-oct-2016)** **Prizes** :The top 5 contestants ( currently studying in Bangladeshi schools and high schools ) will be awarded exclusive Toph goodies. The tasks were prepared by: [user:hasib,2016-09-26] (Hasib Al Muhaimin), [user:Sherlock221b,2016-09-26] (Imran Hasan) and me, [user:Labib6...

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A Tribute to Dennis Ritchie Contest Hello, Everyone. Today is 9th of September. On this very day in 1941, a great computer scientist was born who popularized computer programming all over the world. His name is Dennis Ritchie, creator of C programming language and legendary UNIX operating system. His contribution in the field of Computer Programming is inexpressible. We, the members of the largest [Programming Community of Bangladesh on Facebook](https://goo.gl/69W29z), remember him and his contribution with reverence. In memory of this great Scientist, we are going to arrange a Programming Contest titled **A Tribute to Dennis Ritchie Contest** at the Bangladeshi contest hosting platform [Toph](https://toph.co/). We would like to welcome you to join this contest on [14th of September at 20:00 PM (BST)](https://goo.gl/MYao6J). The contest will be similar to ACM-ICPC style contest and the duration will be about 4 – 5 hours. The difficulty of the problem-set will be mostly equivalent to CodeForces Div2 standard....

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uDebug Tool Hello everyone, I have created a [web-based application](https://udebugtool.com) using the [uDebug API](https://www.udebug.com/API/) and [Judge0 API](https://www.judge0.com/) that allows users to test their code for correctness. The application allows users to enter the code of their solution in several programming languages:  They are then able to search for any competitive programming problem of one of the following online judges: - ACM-ICPC Live Archive - CATS Online Judge - Dev Skill - URI Online Judge - Facebook Hacker Cup - Google Code Jam - Light Online Judge - Toph - UVa Online Judge Input can be provided either by using input from the input table that contains inputs provided by uDebug users, or by inserting a custom input. The calculated outputs of the provided user code and the correct code of uDebug are then compared to one another, allowing users to spot any differences: ![ ](https://i.imgur.com/sUeK3Gt.png...

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Invitation to Participate in Replay of Intra AUST Programming Contest Fall 2020 Hello Good People! We are glad to invite you to participate in the [Replay of Intra AUST Programming Contest Fall 2020](https://toph.co/c/intra-aust-fall-2020-r) which will be held on **Friday, 27 August** at [03:00 pm BST](https://www.timeanddate.com/worldclock/fixedtime.html?msg=Replay+of+Intra+AUST+Programming+Contest+Fall+2020&iso=20210827T15&p1=73&ah=12). The authors of the contest are [user:math10,2021-08-23], [user:Taran106,2021-08-23], [user:robin_aust,2021-08-23], [user:5-head,2021-08-23], [user:tashfiq_ahm,2021-08-23], [user:alamkhan,2021-08-23], [user:Kirin_29,2021-08-23], [user:edge555,2021-08-23], [user:pinanzo,2021-08-23], [user:Professor_,2021-08-23], [user:firebird98,2021-08-23] and [user:S_Rifat,2021-08-23]. Thanks to [user:zeXon,2021-08-23] for coordinating the round and [user:shakil_AUST,2021-08-23] for giving valuable feedback. Recently, we have organized the main round [Intra AUST Programming Contest Fall 2020](https://toph.co/c/intra-aust-fall-2020). T...

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Invitation for participate Replay of DIU Code Trap Programming Contest, Fall 2024 I am really excited to announce the **Replay Contest of the DIU Code Trap Programming Contest, Fall 2024! Organized by DIU Software Engineering Club, Daffodil International University.** If you missed the original contest or want to test your skills under the same conditions, this is your chance to participate! **Date: April 11, 2025 (Friday), Bangladesh Timeline** **Start Time: 8:35 PM (GMT+6)** **Duration: 3 hours** **Platform: [Toph](http://toph.co)** **Contest Link: [Contest](https://toph.co/c/diu-code-trap-fall-2024-r)** The contest features the same problem set from the official DIU Code Trap Programming Contest, Fall 2024. This is a great opportunity to: *Compete virtually with other programmers across the world *Practice real contest-level problems *Prepare for upcoming regional and national contests Open for all competitive programmers — **suitable for first and second semester students at university or college level**. Me,as a problem setter, in...

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A Competitive Programming Assistant using ChatGPT A Competitive Programming assistant using ChatGPT. To use you just have to be logging into https://chat.openai.com on some tab. It uses GPT3.5 by default(ie whatever is served via web), if you have API key for GPT4 you can try that too. For Chrome: - Using ChatGPT: https://chrome.google.com/webstore/detail/cpgpt/cedjhhjppifnfkfkgoflfeddidedofcg/related?hl=en&authuser=0 - Using Bard: https://chrome.google.com/webstore/detail/cpbard-competitive-progra/aciafadgnhadalcioikjioaicelndbeh?hl=en&authuser=0 For Edge: - Using ChatGPT: https://microsoftedge.microsoft.com/addons/detail/cpgpt-competitive-progr/midojdcnbiikoggpniefgimnmbmmkigd ChatGPT is not that great at competitive coding yet. The intension of the extension is not to solve it entirely on your behalf but to generate tips and references which might help you to learn those topics quicker and then focus your time on those stuff which AI can't. Disclaimer: This was built for educational purpose. Please do not use...

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Invitation to Participate in Replay of Cefalo Intra AUST Programming Contest Fall 2022 Hello Good People! We are glad to invite you to participate in the [Replay of Cefalo Intra AUST Programming Contest Fall 2022](https://toph.co/c/cefalo-intra-aust-fall-2022-r) which will be held on **Saturday, 19th August** 2023 at [7 pm BST](https://www.timeanddate.com/worldclock/fixedtime.html?msg=Replay+of+Cefalo+Intra+AUST+Programming+Contest+Fall+2022&iso=20230819T19&p1=73&ah=4). The authors of the contest are [user:alamkhan,2023-08-07], [user:edge555,2023-08-07], [user:_pudinapata_,2023-08-07], [user:S_Rifat,2023-08-07], [user:sahaun,2023-08-08], [user:rithyK,2023-08-08], [user:rahat_chy,2023-08-08], [user:hasib_hossain,2023-08-08], [user:nirjoy_139,2023-08-08], [user:pz1971,2023-08-08] and [user:Remon60,2023-08-08]. Thanks to [user:sahaun,2023-08-08] for coordinating the round and [user:nirjoy_139,2023-08-07], [user:29logN,2023-08-08] and [user:Paul72,2023-08-08] for giving valuable feedback. Recently, we have organized the main round Cefalo Intra AUST Programming Conte...

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Invitation to The Tough Winter Spar 2019 Hello, Codeforces community. It is winter in Bangladesh and in Toph, a traditional long contest named [Tough Winter Spar](https://toph.co/c/tough-winter-spar-2019) is currently ongoing. There are 10 problems in this contest to be solved in 10 days, and the difficulty was intended pretty hard. Although the contest already started before, the last 2 problems were unlocked an hour ago, and I believe you might enjoy solving the problems of this contest, thus this post. The problems of the contest were authored and reviewed by [user:mainstring,2019-12-28]. [user:fsshakkhor,2019-12-28], [user:farhanhasin,2019-12-28], [user:halfblindprince,2020-01-04], [user:souravvv,2019-12-28], [user:Mohaimin66,2019-12-28], [user:Hasinur_,2019-12-28], [user:ishtupeed,2019-12-28], [user:Muhimin_Osim,2019-12-28], [user:upobir,2019-12-28], [user:TarifEzaz,2019-12-28], [user:hjr265,2019-12-28] and myself. We look forward to your participation and hope that you find them useful for practice, best of ...

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[Solved]Need help in coloring a planar graph [Toph -Chor Tintin Tikri] Problem Link: [Chor Tintin Tikri](https://toph.co/p/chor-tintin-tikri) <spoiler summary="Statement"> A new land, what we call “chor”, has emerged. Local people have already given it a name “Chor Tintin Tikri” and taken hold of some part of the land. You are among one of the powerful people so you got a big portion of land for yourself. Now you decided to divide the land into parts and let the local farmers cultivate it. You are a big fan of Pizza Ghat, and pizza is your favorite food. You even dream about pizza. So you have made a decision to divide your newly acquired land in triangular shapes. You have already told your people to start dividing the land. They have started to make each part in triangular shape and put a pole on three corners of each part. But to do this they require a lot of time. After hearing your decision, the farmers have demanded that their land should have different color of poles on each corner. Now after you told the workers who are dividing the lan...

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Invitation to Replay of BUET Inter University Programming Contest 2022 Hello Codeforces, We are glad to invite you to the online [Replay of BUET Inter University Programming Contest 2022](https://toph.co/c/buet-inter-university-2022-r), which will be hosted on [2 August 15:00 BST (UTC+6)](https://www.timeanddate.com/worldclock/fixedtime.html?msg=Replay+of+BUET+Inter+University+Programming+Contest+2022&iso=20220802T15&p1=73&ah=5). Duration of the contest is 5 hours. The main contest took place onsite this Friday organized by BUET. This is an ICPC style contest comprising of 10 problems of varying difficulties. The problemset can be thought as a 4-star gym set. - Authors of this contest are [user:_Ash__,2022-08-01], [user:Anachor,2022-08-01], [user:Arg_007,2022-08-01], [user:imAnik,2022-08-01], [user:irri,2022-08-01], [user:MYNAMEISSHARIFUL,2022-08-01], [user:_no0B,2022-08-01], [user:rebornplusplus,2022-08-01], [user:upobir,2022-08-01] and me. It was additionally tested by [user:mahdi.hasnat,2022-08-01], [user:moidda,2022-08-01], [user:ramisa.alam,20...

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EWU End Of Summer Programming Contest Hello everyone. We are glad to inform you that we are going to host an online individual programming contest on Toph , a Bangladeshi contest platform. The contest will contain 6 problems.It will start at [August 28, at 8:00 PM BST](http://www.timeanddate.com/worldclock/fixedtime.html?msg=EWU+End+Of+Summer+Programming+Contest&iso=20160828T20&p1=73&ah=3)and run for 3 hours. Here's the link [register](https://toph.ws/c/ewu-eos-2016). Problem setters: [user:mosharrafoshy,2016-08-26] [user:_WhiteBeard_,2016-08-26] [user:_BlackBeard_,2016-08-26] and [user:darkprinx,2016-08-26] We would like to thank [user:hjr265,2016-08-26] and his team for the awesome platform. I wish everyone will find the problems interesting and enjoy the contest. Best of luck. **UPD:** The contest is end.Here is the winners- 1. [user:b524,2016-08-28] 2. [user:sgtlaugh,2016-08-28] 3. [user:oneshadab,2016-08-28] 4. [user:Vax,2016-08-28] 5. [user:Sayem,2016-08-28] Congratulation to the...

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Need help for a Disjoint Set Data Structure problem in Toph [Unbelievable Array] [Solved] Problem Link: https://toph.co/p/unbelievable-array My solution: https://ideone.com/USMnVT Verdict: Wrong Answer My approach: For all the same numbers I am trying to group them using disjoint set data structure. I am referring the value of the numbers in each of the index of the array **A** as **color**. So, each of the distinct colors will have a distinct parent. I am mapping the color to the parent using **color** array. Also, I am mapping the parent to the color using **par** array. So, for queries which need replacing one color by other there are two cases where I need to change the value in the **color** and **par** array, one is when both the colors are present and another, the color to be replaced by is not present but the color which will get replaced is present in the array. And for the query which asks for the color value in the index **idx** I am finding it's parent and then displaying the result from the parent to color mapping array (**par**). Can anyo...

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Competitive Companion — Parse problems from the browser Hi! After releasing [CHelper Companion](http://mirror.codeforces.com/blog/entry/56275) as an alternative to the original CHelper extension six months ago, development has been ongoing and CHelper Companion has "evolved" into [Competitive Companion](https://github.com/jmerle/competitive-companion). Competitive Companion is a browser extension for [Chrome](https://chrome.google.com/webstore/detail/chelper-companion/cjnmckjndlpiamhfimnnjmnckgghkjbl) and [Firefox](https://addons.mozilla.org/en-US/firefox/addon/competitive-companion/) that can parse problems and contests and extract the useful data. This includes things like time/memory constraints and sample test cases. While CHelper Companion was only capable of sending this data to CHelper, Competitive Companion works with pretty much all popular tools. Next to that, Competitive Companion is also capable of sending the data to your private tools, without requiring a complex setup. Using it is very simple. Just install the extension, make ...

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BACS Regional Programming Camps 2017 Selection Contest Hello everyone!  We are glad to announce to you that tomorrow [**BACS Regional Programming Camps 2017 Selection Contest**](https://toph.co/c/bacs-camp-2017-s) will be held on toph. Contest will start 3 pm bangladesh time. There will be a online mirror contest also running parallelly with the contest and everyone is welcome to come and participate along with official contestants. Link to online mirror will be available on the site and also posted here tomorrow. There will be six problems to solve in five hours and all of them have subtasks in them and the contest will be held in ioi style. This will be really helpful to ioi contestants we can say. Lastly we say good luck to everyone. Official contestants reminding you again that cheating will get you permanent ban. And remember Judges’ decisions will be final, so dont cheat but be honest and play fair. Contest will be added to codeforces gym after contest ends. **Contest has en...

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Cybernauts'16 National Programming Contest (Replay) The replay of the NSU Inter-University contest is going to start on December 3, 2016 at 1200 UTC and will run for 5 hours. The contest will take place on [Toph](https://toph.co/c/cybernauts16-r). The setters for this contest are: [user:ridowan007,2016-12-02], [user:sn23581,2016-12-02], [user:TarifEzaz,2016-12-02], [user:nfssdq,2016-12-02], [user:Shafaet,2016-12-02], [user:faiyaz26,2016-12-02], [user:d1xlord,2016-12-02], [Zobayer Hasan](http://www.spoj.com/users/zobayer/) and [Abdullah Al Raqibul Islam](http://uhunt.felix-halim.net/id/38946). Good luck and have fun!

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Criterion 2020 Round 1 on Toph Dear Codeforces, I am very excited to invite you to our first round of Criterion 2020 Round. The round will start from 0900 UTC on 31 January 2020. Criterion rounds will be held once every two weeks and will have 5-6 problems over the duration of 2.5 hours. You can register for the contest [here.](https://toph.co/c/criterion-2020-round-1) The authors of the today's contest are: [user:Dhruba10414,2020-01-31], [user:Hasinur_,2020-01-31], [user:A_Modern_Desperado,2020-01-31], [user:shefin.cse16,2020-01-31], [user:I_love_ProParThinkNot,2020-01-31], [user:Hasnaine_,2020-01-31] and [user:tanus_era,2020-01-31]. See you in the arena!

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BUET CSE Day 2016 Programming Contest Replay The replay of the BUET Inter-University contest is going to start from 1200 UTC today and will continue for five hours. The contest will take place on [Toph](https://toph.co/c/buet-cse-day-2016-r). The setters for this contest are: [user:Shafaet,2016-11-14], [user:nfssdq,2016-11-14], [user:moinul.shaon,2016-11-14], [user:jehad131,2016-11-14], [user:kzr.buet08,2016-11-14], [user:ridowan007,2016-11-14], [user:Farsid,2016-11-14], [user:VUAcoder,2016-11-14], [user:Jhamra,2016-11-14] and [user:shohag,2016-11-14]. Good luck and have fun! UPD 1: The final ranklist is [here](https://toph.co/c/buet-cse-day-2016-r/standings). Tutorials can be found [here](https://docs.google.com/document/d/1tW2Zg4U34b9mIhp95otdP3Sjs2VziJZiLIwph6QkwiY/edit?usp=sharing). UPD 2: Problems are also available for upsolving [here](https://toph.co/problems/search?q&contest=5827382504469e1d54aac2c8).

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Practice Contest for the 2019 ICPC Asia Regional Dhaka Site Preliminary Hello world! We would like to invite you to the Practice Contest for the 2019 ICPC Asia Regional Dhaka Site Preliminary. The contest will start from 0900 UTC on 20 September 2019 and will run for 5 hours. The contest will take place on Toph. You can register for the contest [here](https://toph.co/c/practice-icpc-2019-dhaka). The problem authors of this contest are: [user:I_See_You,2019-09-20], [user:BishalG,2019-09-20], [user:jackal_1586,2019-09-20], [user:hjr265,2019-09-20], [user:codename27,2019-09-20], [user:J-C,2019-09-20], [user:kfoozminus,2019-09-20], Fahim Ferdous Neerjhor, [user:mainstring,2019-09-20], [user:Evade_RAbid,2019-09-20], [user:Joty,2019-09-20] and [user:TarifEzaz,2019-09-20] See you in the contest arena.

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The Tough Summer Spar 2016 22 July 2016 1200 UTC We are pleased to announce you that we are going to host a long contest on Toph, a Bangladeshi contest platform. The contest will have 12 problems. It will start at 1200 UTC and will continue for 10 days. Scoring follows ACM-ICPC rules. Here's the registration link: [register](https://toph.ws/c/tough-summer-spar-2016) The setters are: [user:TarifEzaz,2016-07-22], [user:Labib666,2016-07-22], [user:flash_7,2016-07-22], [user:_Kryptonyte_,2016-07-22] and [user:jackal_1586,2016-07-22]. We would like to thank [user:hjr265,2016-07-22] and his team for this awesome platform. We hope everyone will find the problems very interesting to solve. Good luck and have fun. UPD: [Winners and Editorial](http://mirror.codeforces.com/blog/entry/46409)

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Replay Contest of SUST IUPC 2019 on 1 May at 1000 UTC Hello everyone, We would like to invite you for the replay contest of Shahjalal University of Science and Technlogy Inter-University Programming Contest 2019. The contest will start from 1000 UTC on 1 May 2019 and will run for 5 hours. The contest will take place on Toph. You can register for the contest [here](https://toph.co/c/sust-iupc-2019-r). The authors of problems of this contest include: [user:I_See_You,2019-04-30], [user:knight_of_thirteen,2019-04-30], [user:triploblastic,2019-04-30], [user:codename27,2019-04-30], [user:rumman_sust,2019-04-30], [user:J-C,2019-04-30], [user:nodim,2019-04-30], [user:TarifEzaz,2019-04-30], [user:olee12,2019-04-30], [user:FORHAD-SUST-BD,2019-04-30], [user:mk_Shahriar,2019-04-30], [user:jackal_1586,2019-04-30], Abdullah Al Maruf and Md. Saiful Islam Khan. See you in the contest arena.

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The "Tough Winter Spar" on 20 December 2018 1200 UTC It's winter in Bangladesh and Toph is back with "Tough Winter Spar 2018" contest. The contest will start at 1200 UTC on 20 December 2018 and will run for 10 days. You can register for the contest anytime before or during the contest. The registration link is [here](https://toph.co/c/tough-winter-spar-2018). The setters for this contest are: [user:Introverted,2018-12-19], [user:jackal_1586,2018-12-19], [user:fsshakkhor,2018-12-19], [user:I_See_You,2018-12-19], [user:Tanmoy_Datta,2018-12-19], [user:shahed_ahmed,2018-12-19], [user:sadman.rizwan,2018-12-19], [user:TarifEzaz,2018-12-19], [user:Evade_Rabid,2018-12-20] and [user:Kitorp,2018-12-19]. We would like to thank [user:hjr265,2018-12-19] for the amazing platform. See you at the contest arena!

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The "Tough Winter Spar" on 20 January 2017 1200 UTC We are pleased to announce you that we are going to host our second long contest on Toph, a Bangladeshi contest platform. The contest will have 10 problems. It will start at 1200 UTC on 20 January 2017 and will continue for 10 days. Scoring follows ACM-ICPC rules. The contest is named "Tough Winter Spar 2016" because it was originally scheduled for December 2016. Here's the registration link: [register](https://toph.co/c/tough-winter-spar-2016) The setters are: [user:prophet_ov_darkness,2017-01-20], [user:TarifEzaz,2017-01-20], [user:Labib666,2017-01-20], [user:flash_7,2017-01-20], [user:_Kryptonyte_,2017-01-20], [user:Tanmoy_Datta,2017-01-20] and [user:jackal_1586,2017-01-20]. We would like to thank [user:hjr265,2017-01-20] and his team for this awesome platform. We hope everyone will find the problems very interesting to solve. Good luck and have fun.

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Criterion 2020 Round 2 on Valentine's Day We would like to invite you to the second edition of Criterion 2020 Round. The round will start from 0900 UTC on 14 February 2020. Criterion rounds will be held once every two weeks and will have 6 problems over the duration of 2.5 hours. The contest will be hosted on Toph. You can register for the contest [here](https://toph.co/c/criterion-2020-round-2). The authors of the contest are: [user:Anachor,2020-02-03], [user:mainstring,2020-02-03], [user:0pangktey0,2020-02-03], [user:fsshakkhor,2020-02-03], [user:Joty,2020-02-03], [user:TarifEzaz,2020-02-03], [user:jackal_1586,2020-02-03], [user:I_love_ProParThinkNot,2020-02-03] and [user:ishtupeed,2020-02-03]. See you in the arena on Valentine's Day!

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Criterion 2020 Round 3 on 28 February We would like to invite you to the third edition of Criterion 2020 Round. The round will start from 0900 UTC on 28 February 2020. Criterion rounds are being held once every two weeks and will have 5-6 problems over the duration of 2.5 hours. The contest will be hosted on Toph. You can register for the contest [here](https://toph.co/c/criterion-2020-round-3). The authors of the contest are: [user:fsshakkhor,2020-02-26], [user:0pangktey0,2020-02-26], [user:jAckAL_1586,2020-02-26], [user:Joty,2020-02-03], [user:TarifEzaz,2020-02-03], [user:I_love_ProParThinkNot,2020-02-03] and [user:ishtupeed,2020-02-03]. See you in the arena!

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NSU Code Master 2016 (Replay) 16 June 2016 0600 UTC We are pleased to announce you that we are going to host our contest on Toph, a Bangladeshi contest platform. This contest is an online mirror for the "NSU Code Masters 2016" that has taken place earlier this month. The contest will start at 0600 UTC and will continue for four hours. Here's the registration link: https://toph.ws/c/nsu-code-masters-2016-r The setters are: [user:forthright48,2016-06-15], [user:TarifEzaz,2016-06-15], [user:ridowan007,2016-06-15], [user:Labib666,2016-06-15], [user:hasib,2016-06-15], [user:_Kryptonyte_,2016-06-15] and [user:jackal_1586,2016-06-15]. We hope everyone will enjoy the problems. Good luck and have fun.

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Need help to solve "Toph — Very Dirty String" Need some help to solve [Very Dirty String](https://toph.co/p/very-dirty-string) problem. Short Description: Given three strings A, B and C. Find the longest common sub-sequence of A and B, which have C at-least once as a substring in it. Input: There will be T test cases. For each test there will be three lines describing string A, B, and C. Constraints: 1 ≤ T ≤ 100 1 ≤ |A|, |B|, |C| ≤ 100 My approach: I tried it using normal recursive LCS with extra another state pointing the index of string C i'm trying to match. [here](https://ideone.com/5bo1nl) is my code. Sorry for my bad English.

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Help Needed in TOPH Problem. How Can I solve this problem!https://toph.co/p/crypto-number Will be grateful if anyone can help. Thank You. TLE-O(q*sqrt(k)) time.

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Toph - Keep Moving (Game Theory + Graph + DP) Problem Link: https://toph.co/p/keep-moving Solution Link: http://ideone.com/L7pxbT My solve() method where I'm trying to implement dp is wrong. Any help to correctly implement the dp portion will be really appreciated.

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Help! LIDS | Toph I have recently started learning digit dp and was stuck in a problem [Longest Increasing Digit Subsequence](https://toph.co/p/lids). After trying for a very long time I was unable to solve it. Help me with the concept and approach to solve the problem.

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