Sundays are fun days. You get a day off from the routine and indulge yourself into some fun and exciting stuff. And if you are school kid, it’s all about you. You get your choice of food, movie, and you can do whatever you want to. So, who are we to deviate from the established? We too have the last Sunday of the month reserved for you with our LunchTimes. And we hope you have been enjoying them.
The February LunchTime 2015 was yet another fun Sunday at CodeChef. The contest was set and translated into Russian by Sergey Kulik, which ensured the perfect seasoning of fun and learning during its course. And it was testified by Roman Furko. The editorials for the problem set came from the BalajiGanapathi Senthilnathan and the Mandarin flavors for the problem set came from Minako Kojima. All that took place under the moderation of our contest admin Praveen Dhinwa. Our problem setter made sure that the problems have the perfect balance between a testing and an exciting problem set. And with the looming shadow of exam season in the March, the February LunchTime was a great opportunity for our young friends in school to break out and rejoice in the exhilarating 3 hour of the contest. And they did exactly that as the contest started.
We have seen some quick submissions in our contests, but not many of them have been an AC in the first minute of the contest. And the February LunchTime became one of the rarities in that department. The first one to crack the LUCKFOUR was fataleagle from Don Mills Collegiate Institute. It is worth mentioning that the final submission for the contest also came from fataleagle. Now, that is a job well done. But it was that very first submission from him that set the pleasing Sunday LunchTime rolling. And for the next 3 hour the number of submissions on LUCKFOUR just kept on growing. However, the submissions were not as high as some we have seen in the past. But it was enough to make the competition exciting till the very end.
The second problem to receive large number of submissions was WPROB, which received its first accepted submission in the 16th minute from azukun. Now, while the submissions on the problems were not growing briskly, but within an hour we had all the four problems from the contest solved. And to introduce you to the young programmers who solved them, let us present you our rank list.
First the non-Indian top 10:
And now the Indian top 10:
A big round of applause to for all our wonderful participants and winners, without whom the contest would not have been possible!
The names that adorned both the rank tables comprise of names that have been there before and names that were making their first appearance there, and that gives us immense pleasure. However, the star there is meteora, who by now has become a force to be reckoned. She not only has made a mark on the LunchTimes, but also is fast becoming a frequent visitor on our Cook-Offs and Long Challenge rank tables. And it gives us huge pleasure. We want more and more geniuses from schools to come up and make their senior counterparts work harder to save their places on the rank tables. So, if you think you can do it, pull up your socks and get on to it. And to help you with your preparations we have our editorials to help you understand the best approach towards solving these problems.
So, enjoy these delicious editorials and strengthen your preparation.
With that, it’s now time to move towards the next blog post, which will be served soon after a little garnishing. We hope you have been enjoying the updates from CodeChef’s blog and if you have any feedback, good, bad, or a little banter do send them all at: email@example.com
We now enter the exam season with March. So, All the best! Break A Leg.
Till next time, Sayonara.
We are delighted that we turned Senary this March. All this would not have been possible without the problem setting panel in our kitchen. We are truly thankful to everyone in our kitchen for all those delicious problems, mouth watering editorials and awesome contests. We truly appreciate the efforts that our chefs put behind making this possible.
We are happy to announce that we have revamped the problem setting guidelines. You can read more about it here:
Some highlight of the newly released guidelines:
If you would like to join our kitchen as problem setter or tester or editorialist, you can apply here.
With Love and Regards,
Cook-Offs have always fascinated us. They are short, they are filled with action, and they tend to bring out the best in everyone in their two and half hour. Now, while that’s all the fun part, our Cook-Offs also presents us a stern test for our servers and if we mildly put that, our servers have not enjoyed them as much as we have. The recent being the January Cook-Off 2015. And we all know how that went. Coming on the heels of the disastrous COOK54, the February Cook-off 2015 had a lot riding on it. The joy and excitement that normally isthe prologue for our Cook-Offs was overridden by the appalling memories from the past Cook-off. But, this time around we were ready. We have made the necessary fixes and were hopeful of having a smooth contest. And as the clock hit 9:30 pm on the Sunday night, our haunting memories were taken over by the sheer elation of the smooth start of February Cook-Off 2015. And it’s safe to say now, that we had a wonderful contest and that the days of server crashes are behind us now. However, we are still keeping our fingers crossed.
For February Cook-Off 2015 we had an all Indian problem setting panel featuring Devendra Agarwal, Anudeep Nekkanti, & Amit Pandey as problem setter, tester, editorialist respectively. And, the Mandarin & Russian translations came from Gedi Zheng & Sergey Kulik correspondingly. The proceedings of the contest were ardently administered by our contest admin Praveen Dhinwa. The young problem setters poured all their experience and added a touch of freshness to make sure that the problems of the contest are good enough to not only keep the participants engaged for two and half hour of the contest duration, but also makes them pull their hairs. And that’s exactly what happened in the contest.
The February Cook-Off 2015 started off to a galore of accepted submissions on TRISQ as we saw the 48 out of 50 first submissions in the contest on it. And out of those 48, 47 were accepted. So, let’s just say fitting squares in triangle is not as hard as it sounds. As we moved into the contest the submissions kept pouring in and with accuracy percent of 81.73, TRISQ was the most solved problem. However, the rate of submissions on the remaining problems was not pretty much the same. Making strategy for the World Cup is never easy, and our participants found it just before the world cup. However, there were some smart strategists who managed to find the perfect strategy and cracked the problem. The remaining three problems namely SUBARRAY, FOMBRO, and SPSHORT too proved to be tough nuts to crack. However, none of them remained unsolved. Overall, the problem set was nicely balanced with problems for the learners and pros alike.
While the problem set kept testing the participants, it also made the rank table change frequently and the best thing here was that all the names on the rank tables have been here before and hence it was tough for us to write anyone off till the very end. From fhlasek to uwi the fight was on right from the very first submission to the very last. The fight between lyrically, karolis_kusas and fhlasek turned out to be the fiercest of them all, with fhlasek eventually triumphing them both. Now, to meet the final names on the rank tables, let us take you through them.
First, the non-Indian top 10:
And now, the Indian top 5:
A big round of applause for all the winners, and congratulations to all the participants for a wonderful contest!
Now, let us give you the final stats for the February Cook-Off 2015:
While those numbers brought huge smiles on our face, we are excited to see them go further up and have even bigger & smoother contests.
Now, before we move towards our February LunchTime 2015 blog post, we would like to bring your attention at no 5 of the Indian rank table. We have meteora sitting comfortably at number 5 on a Cook-Off rank table. If that’s to be taken as a sign, the college students will certainly face tough challenge from the young participants in the schools. And we are quite excited about it. We are sure you too are. So, if you are in college, it’s time for you to pull up your socks and if you are in school it’s time to announce your arrival on the big stage in style. So get ready.
To help you prepare for the coming contests, it’s very important to clear every single doubt or query that you might have had in the past. And we know a brilliant way of doing that. It’s our editorials. So, let us serve them for you.
It’s now time to put pen down on this lovely tale of February Cook-Off 2015 and move towards the February LunchTime, which saw the young brilliant minds from schools gearing up to announce their arrival at the global programming platform.
We hope you had a wonderful February Cook-Off and love filled month of February. For any query or love greetings you can always reach us at: firstname.lastname@example.org
Or can give us a call at: (022) – 30797709
That is all for now from CodeChef.
Till next time, adios.
See you all at the contest.
If you have never made one, you will never understand how herculean the task of deciding a team name is. We want our team names to reflect our attitude, to communicate, and at times to leave a legend. Whether it’s the serious doers or the dabblers, no one takes their team names lightly. This is why when you have to register a new one every time you enter a competition, it takes the fire out of it.
So, we have decided to let you use the same team name that you once registered with grave intensity. We are sure you must have started digging deep into the backyard of your memory in search of that one team name that you wish you could reuse or could register. And to find all the teams that you have made till now, all you need to do it go to your profile and click on the list given against “Team List”. So, while you are at it, there are a couple of things more that we want you to make note of.
So, what are you waiting for? Put your team names to work.
Competing in teams is a great way for preparing for the ACM ICPC. Once you form a team, you can keep taking part in many team contests that are hosted on CodeChef by institutions and organisations. You can also host your own team contests for your group of friends or school or college or organisation. It provides a great opportunity for you to elevate the programming culture in your institute. To know more about hosting a contest with CodeChef visit here.
We started the new year with the hope of making the first Cook-Off of this year as the most memorable one. And we did ensure that we get the maximum crowd in for the celebrations. Anudeep Nekkanti was handed over the responsibility of creating the problem set. Who else could have done the job justice? Lalit Kundu, Minako Kojima and Sergey Kulik completed the team.
Not for the reasons that we wanted, the story of January Cook-Off 2015 will still be remembered. For the load that the server could not handle and crashed, many times! This will be the first ever unrated Cook-Off at CodeChef.
The problems of Anudeep Nekannti were much appreciated. To add to that, the problem statements were named after the members of our team at CodeChef. We take this opportunity to express our gratitude to Anudeep for this gesture and an awesome problem set. We feel humbled and sad to have let this problem set down.
When a contest goes wrong, it is you, the users, who suffer. We as organisers share the complete responsibility for this to have happened and apologise to all of you who took part in the contest. We goofed up once again. The biggest sufferers are the problem author and the panel who spend a huge amount of time and effort to bring the problem set to you. We apologise to Anudeep and the entire problem setting panel, including Lalit, Minako, and Sergey for not giving them the steady two and half hours that they needed to have for this deserving problem set. We are sorry.
To be fair to all the participants who put in all their heart and soul trying to access the problems, we are making this Cook-Off unrated. Yes, you will not be rated for the contest and there will not be any winners. And we leave it there.
Now, let us explain on what went down in those seemingly never-ending two and half hours and what have we done to ensure that nothing like that ever crosses our way again.
What was the “Cause”?
We had just launched a new feature to show the accuracy and the count of solutions to “subtask” type problems on the contest page separately. This made us fire some expensive queries, which shot up the load on MySQL. Some indexes were missing and MySQL was hogging more CPU. We did not do any profiling after the launch of this feature. The dogpile effect that occurs at the start if any contest and something that we fought hard to reduce game back in a big way and never let the MySQL server recover. It ensued the site crashed. And the rest you know.
What we did to address it then?
It took us a while to identify this. As soon as we did that, we took down the feature, which although made the site run normally, took a lot more time than we would have wanted. And way more time for the contest to be fair to anyone. We also fix the expensive queries in the mean time. However, it was only a temporary fix and we went straight to the drawing board to find a permanent fix to the problem.
Do you have a permanent fix now?
Well, we have found a fix, now whether it is permanent or not, we will find that out in the upcoming Cook-Offs and other high octane contests in 2015. By the time of writing this blog, we have run many contests including the February Cook-Off, and things seem to be under control. However, to be frank, we have not yet received as much load as we did in the January Cook-Off.
What is the fix?
To start with, we have profiled and fixed all the misbehaving queries to make sure that they do not cause any such trouble. While investigating the cause, we also found that our rate limiter was put off, which contributed significantly to increase the load. We have enabled it again. Also, we took this opportunity to dig hard and identify what can be better fixes to reduce the dog pile effect at the start of our contests and improved the way we were creating our cache as well as locking the cache. So far this has worked and we believe the issue has been fixed.
We know, this is not the first time we have “goofed up” in a Cook-Off and we have tried hard to get things fixed. So, do not get dismayed and keep the problem cracking going. Also, keep sending your love for the chefs at CodeChef. We do need that.
That will be all for our unrated January Cook-Off 2015. We hope it answers your queries regarding the issue during the contest, the ratings or the winnings of the contest. However, if any of you still have it, feel free to write to us at: email@example.com
Till next time, TA-TA
See you at the contests.
Chocolates, Roses, Cute & Cuddly soft toys, romantic dinner reservations, and many things pink. This is the list that almost everyone makes as soon as February starts. Even though it falls in the midway, the preps for Valentines’ Day start way in advance. But if you are on planet CodeChef, the first thing that baffles you with the arrival of February is, the Cook-Off will fall during the Long challenge, so what should we do? Now, call us dead heart, but that actually is what struck us this February as well. And after the disastrous January Cook-Off 2015, it was of paramount importance that our February Cook-Off goes smoothly. So, we got down to work straight away. And as you all it was all worth it. After all, had anything gone wrong with our contests, your Valentines too would not have been all that glamorous. Would it?
First in line was the February Challenge 2015. Set by our romantic at heart problem setters Dmytro Berezin, Vasia Antoniuk, Sunny Agarwal, Praveen Dhinwa, Ilya Malinovsk, Kevin Charles Atienza, Alexey Zayakin, Chao Chandan Boruah, and Abhra Dasgupta, the February Challenge had the problem set that demanded a lot of love and caressing. And to make sure that that they get it, we had them tested by Jingbo Shang and Pushkar Mishra. The red rosy editorials came from Florin Elfus, while the Russian and Mandarin flavors for the problem set were provided by Fedor Korobeinikov and Gedi Zheng. With that the quixotic set up for your affair with the problem set was ready.
On the beautiful Friday afternoon, the contest began with all 10 problems shining on the problem page. It was love at first sight for many of the early party goers. It all began with CHEFCH, which saw the first submission inside the first five minutes of the contest. And the flow of submissions never slowed down, all through the contest. Although the problems on the receiving end kept on changing and the so did the names on the rank tables. While CHEFCH accepted everyone’s love, there were few who got lucky with DEVLOCK, XRMTRX, and the same was the case with participants who were after CUSTPRIM.
While the season of love was seeing few heart breaks and more smiles, we encountered a small technical problem with our challenge problem CHEFCSC. The problem setters tried to fix the issue; however, after identifying it as beyond repair, they took a conscious decision to add a new challenge problem. With still close to half way remaining into the contest, the new challenge problem CHPUZZLE was received with the equal love and fervor. But there can only be one name atop the rank table and to know who it was this time, let us take you through the rank tables.
We start with the non-Indian top 10:
And the Indian top 20:
Let’s now move towards the special achievers category with the top 3 scorer for challenge problem CHPUZZLE:
First the non-Indian top three:
And the Indian top three:
Now, we move towards our young achievers from school:
First the non-Indian top 5:
And now the Indian top 5:
All those names came from a huge pool of participants who made the February Challenge 2015, such a huge success. And here are the final stats for the contest.
A big round of applause for all you wonderful people!
Even before the February Challenge 2015 concluded we found ourselves gearing up for the February Cook-Off 2015, which we had to make sure that goes smoothly. How did it go? You all know the answer, but still we will cover it in a separate blog. But before that, let us conclude this post by taking you through the luscious editorials for the contest.
That is all that we have for us from February Challenge 2015. We hope you enjoyed thoroughly enjoyed the love filled February Challenge 2015 and are enjoying the ongoing March Challenge 2015.
Do share your love and feedback with us on the contests with us at: firstname.lastname@example.org. We love hearing from you guys.
We now move towards our post on February Cook-Off 2015 and will serve it soon.
Till next time adios.
See you at the contests.
Women’s struggle for equality has been there since the beginning of mankind. It holds true even in the world of programming. Despite their huge contributions to the computing world, names like Adele Goldberg, Grace Hopper, Ada Lovelace, and many others still do not get as much mention as they should. And even though we have come a long way, the stark reality has not changed much.
Still when asked about the great women programmers in current times, sarcasm takes over the names like Joanna Rutkowska, Anna Patterson, Caitlin Colgrove. And we think it’s about time we change that. The theme of this years International Women’s Day is “Make It Happen”. So, let’s come together and be a part of the change.
We have already seen some awe-inspiring women programmers on CodeChef in meteora, xiaodao, rosyish in our past contests and we are sure there are many more. In honor of the wonderful women all around the world, we will be dedicating special prizes to the women programmer in our March Challenge 2015, as a small gesture to celebrate their achievements.
For our March Challenge 2015, we will be honored to present the top women programmers around the world:
And CodeChef goodies to rest of the names in the list of top ten women.
So, let us bring out all the amazing women programmer we know and celebrate their magic. And if you are a woman, let us give the men a run for their money in the March Challenge 2015, making them work twice as hard as they do. We know you can “Make It Happen”.
We will be honest, the road to January LunchTime 2015 was not the most glamorous one. We had just experienced, what perhaps was the worst Cook-Off in the history of CodeChef, and once again we were confronted by a short contest. Yes, the participation in our LunchTime has not been much in comparison to the Cook-Offs. But we have started getting numbers in the higher range. And it was imperative that we run this contest smoothly, as the targeted participants here are the school kids and you do not want to put up a bad show for them. So, this time around we were a tad better equipped. We had brought in some fixes and were hoping for a smoother contest this time around. And that’s exactly what we got. We were even happier to see that even in terms sheer numbers, the January LunchTime 2015 was among the biggest LunchTime contests we have had.
Now, after the prologue to January LunchTime 2015, let’s take you through the course of the competition and how it faired. The contest problems came from Pavel Sheftelevich, who also translated the problem statements in Russian. The testing of the problems was handled by Roman Rubanenko, who has been behind so many of our successful LunchTime contests. The Mandarin flavor for the problem set came from Gedi Zheng. And finally the cherry on top in the form of the elaborate and delectable editorials came from Paweł Kacprzak. With INOI 2014-2015 just at a week away, the January LunchTime came as a great opportunity for the aspirants to test the waters and they did enjoy it.
The January LunchTime 2015 started at its scheduled time, with no glitch at all, and that brightened up our Sunday. It was now up to the participants to come and sprinkle their magic all over. And the first one to make a correct submission was evanlimanto, it was also the first submission of the contest. And it was followed by several other accepted submissions well within the first hour of the contest. We saw plenty of familiar and big names surfacing on the rank tables in uwi, yutaka1999, kaizero, and many others. To have those names pop up in the early stage of the contest means good things will follow as the contest proceeds. And that’s what exactly happened.
After the first hour of the contest we had zxqfl of University of Toronto Schools holding the top spot on the non-Indian rank table, while the Indian table was graced by meteora, a force to reckon with in our LunchTime contests. But closely tailing the rank leaders were some names including animesh_f, fataleagle, bhagatdivesh12 and many more, to look forward to in the coming contests. The race to the top started heating up as we moved into the contest; however the names at the top of the table did not change much. And as the end approached the winners for the contest became more and more apparent. So, let’s meet them all.
We start with the non-Indian top ten performers from schools:
And now we move towards the Indian top 10:
A big round of applause for all our little wizards from schools across the globe!
Now, let us give you the final stats of January LunchTime 2015:
We hope you all enjoyed the contest and to see you all in the impending contests as well. If you enjoyed the contest, we are sure you are going to love the editorials for it. They will help you overcome any small doubt that you might have in your mind. So, head over to the discussion forum and enjoy them.
Now, before we close down this blog post, let us take you through our blog where we have put up some new and exciting posts about what we have been up to. So, do enjoy them, share them, and send your feedback on them to us. We love hearing from you guys.
With that, it’s now time to wrap up this blog post and start working on the February ones. If you have any queries or quarrels for us, feel free to shoot them to: email@example.com
You can also reach us at: (022 – 30797709)
Till next time, TA-TA
See you at the contests.
In our attempt to build a closely knit community of computer programmers from all over the world, we had introduced a silent “group feature” for our discussion forum sometime back. Currently not available for everyone, the objective behind the feature was to let you carry on a conversation, which is pertinent to a specific set of people cutting down the noise. If you wish to create a group of your school or college or campus chapter, you need to get in touch with us and we will do the needful. We already have some groups running like the:
These groups follow the same question answer format along with the features like tagging, searching, commenting and voting the posts. They can be public or semi private to discuss any programming related topic, event, or can prepare for an upcoming contest with other aspirants. While all this sounds awesome, there was a slight shortcoming with the said feature in the form that, unlike our discussion forum, the members did not receive any notifications for their subscription when there was an activity on the group.
So, in order to keep the members of the group updated on the happenings, we have brought in a “subscription” feature. With this we have taken the primary subscription setting from forum to the group, allowing you to receive notifications for all or any activity that you choose to subscribe to in the group. So, the days of missing on updates from the group are gone behind. Go and subscribe to all the alerts from the groups you are part of, and if you are not part of any, but want to start one for your institute or organisation or your programming club, do get in touch with us.
Now, while that small change caters to a limited set of users, here’s something big for all of you. It gives us immense pleasure to introduce the addition of “LaTeX mathematical typesetting” to our discussion forum. With LaTeX the painful exercise of uploading images for every mathematical formula you want to insert in your question or answer, is a fossil now. This was a much wanted feature specially for writing good fun editorials. LaTex allows us to write mathematical expressions in a markup style, which is somewhat akin to HTML. To know more about LaTex read below:
We hope that these new features will make your stay in the discussion forum seamless. However, if you face any trouble or have any queries, do write in to us at: firstname.lastname@example.org. Also, if there is any feature that you think that can enhance the overall experience on discuss or on CodeChef do write into us. For now, play around with these new offerings from our Chefs.
With January Challenge 2015, we not only started a New Year, but also barged into a new era. It is an era where procrastinating typing a code or abstaining from coding due to the dearth of a compiler are all things of past. You, now have more security for your code and less excuses to stay away from coding. The era of CodeChef’s “Code, Compile, & Run” environment has started, so put all your excuses of not coding to rest and just press “Ctrl” + “;”, type IDE and get started.
Marking the beginning of this new era with us was one of the largest participation in any of long challenges. On the backdrop of all that, we think we all had a pretty great start to our New Year. And what followed that epic start complemented it equally well, making January Challenge 2015 one of the biggest long challenges we’ve had here on CodeChef.
Before we go any further let us thank the real architects of this bravura first contest of the year 2015. The problem setting bench was graced by Dmytro Berezin, Fedor Korobeinikov, Gaoyuan Chen, Lalit Kundu, Praveen Dhinwa, Sergey Nagin, Snigdha Chandan, and Sunny Agarwal, while the responsibility of testing all those problems went to Shiplu Hawlader. The editorialist penning down the editorials for all those problems was Lalit Kundu, while the Russian and Mandarin flavors of the problem statement came from Sergey Kulik and Gedi Zheng. If numbers are anything to go by, we are pretty sure that you all enjoyed the work of the aforementioned gentlemen to the very last moment. If you think we are wrong, do send us your opinions, we’d love to hear your side of the tale.
With a new playground to play, enticing problem set, and plethora of cool features to play with, it was finally the turn of the participants to come and make their presence felt at the first CodeChef party of the year. And boy, did they come. The contest opened to the flurry of accepted submissions on GCDQ, SEAND2, and CHEFSTON, with the latter one getting the majority of them. The flow of submissions steadied as we reached the half way stage of the contests, but with the end still far from sight, no one was ready to go easy on that paddle. But the path from here onwards was not all that undemanding.
By now, the easy problems like CHEFSTON, have had seen their fair share of submissions and now the focus of the table leaders shifted onto the likes of XRQRS, RANKA, SEALCM, and QSET. Each of them made life tough atop the rank table. But after spending most of the time on top of the rank table, the likes of mugurelionut, protocolocon, argos and some more knew exactly how to crack those few problems standing between them and the glory in the first long challenge of year 2015. And while they were busy finding their way to the top, in came the terrific trio of msm1993, kutengine, and rns4 and before anyone could understand what happened, they had their names cemented atop the rank table. Though they entered pretty late into the contest, but they hardly took anytime in reaching on the top of the table. And like a thrilling end to an exciting superhero movie, the January Challenge 2014 concluded with a mix of familiar and new names shining atop the rank table.
Now, let us meet the winners of the first Long Challenge of the year 2015.
As always we start with the non-Indian top 10:
The Indian top 20:
Let’s now meet the special achievers, in participants with highest scores for the challenge problem SEAND2.
The non-Indian top three:
The Indian top three:
And now it’s school time. Let’s meet our top five global as well as Indian school students from the January Challenge 2015:
We start with the non-Indian top 5:
And now, the Indian top 5:
Give a big round of applause to all the winners of years’ first long challenge and to everyone for making it such a big one.
Now, to tell you exactly how big the contest was, here are the final stats of the contest.
With those numbers to kick start our year, we are sure it will be a good one. And with you all by our side, we certainly can make it a memorable one.
Now, before we part ways and move towards the January Cook-Off 2015, let us take you to the editorials for the contest, which we are sure you would have tasted by now. However, if you haven’t already you can go it now.
And with that, we will enfold this January Challenge 2015. We hope you had a great start to the year with the contest as we had. If you have any concerns or queries, regarding the contest feel free to drop them at: email@example.com
You can also give us a call at: (022) – 30797709
That will be all for now. Till next time, adios.
See you all at the contests.