Winter perhaps is the most beautiful time of the year. It makes the environs alluring, and us, lazy. Thus, the delay in putting up the blog posts for our recent contests. Our November Lunchtime was set up in a mildly chilly Sunday morning, and despite the falling temperature, there was no drop in the warmth of the contest.
The young minds from different part of the globe were up and ready to feast upon the problem set of Sergey Kulik, who was the editorialist and Russian translator for the contest. And a fantastic one in all three departments. His problem set were tested by Roman Rubanenko, who has been a part of 5 Lunchtimes out of the 6 that we had till now, making him a well-liked name in the programming community. Accompanying them on the panel was Minako Kojima, with her Mandarin translation of the problem statements. With everything in place, we were all set for an engaging contest, on a beautiful Sunday morning.
The November Lunchtime had a rather calm opening, with the first submission coming in the 15th minute of the contest. However, that can also be because the initial technical glitch which forced us to go offline for some time. Although we came back quickly, we are still sorry for it. To make up for the initial hiccup we extended the contest to give everyone a fair shot at the problems. As soon as we came back, the submissions came pouring in and kept coming all through the contest. Our winner zeulb, announced his arrival in the 15th minute by cracking NUMBERS in his first submission. It was soon followed by another successful submission on LMA1. With two in two, zeulb made his intentions very clear. However, yutaka1999 seemed unperturbed, with that and made it tough for him to get away with the contest. While zeulb made 6 submission to emerge as a winner, yutaka1999 took the first runner up spot in 4. All that indicates the development of a healthy competition in coming Lunchtime contests and we shall keep a close watch on it.
As the battle at the top of the table, the fight among the other participants also kept on growing, keeping everybody interested in the contest until the very end. To see who ranked where, let us meet and greet our top ten winners from the rank table. These are names of some of the brightest budding programmers among us, and we will be seeing a lot of them in coming time.
All budding programmers along with many others who took part in our Lunchtime contest have already announced their arrival on the big stage and are set to take on the big guns soon. So, let us put our hands together and congratulate all these talented individuals.
The total stats for the November Lunchtime 2013 were as below:
With that, we would wrap up the tale of the November Lunchtime, which despite the few hiccups, turned out to be a fun contest for everyone associated with it. We hope you are enjoying the dropping temperatures as much as we are, and on yet another fine chilly Sunday morning we will see you all with our December Lunchtime 213. It will be the final contest of the year, so in anticipation of ending the year on a high, we invite you all to take part in it.
For all the love, you can always reach us at firstname.lastname@example.org. We love receiving both from you all.
Till next Lunchtime, adios from everyone here at CodeChef.
For a lot of us, the November Cook-Off 2013 was yet another reason to celebrate. While the problems added to the flavors of the month, the competition among the participants dropped the mercury for everyone taking part in the contest. The numbers, in comparison to some other high-participation-cook-offs, were not soaring high, but despite that, the contest was convivial.
The responsibility to make November Cook-Off fun for us all was well handled by our problem-setting panel. While, the flavors of the contest in the problems came from Vineet Paliwal, to test them of taste we had Roman Rubanenko, who also added a pinch of Russian flavor with the translations. The Mandarin translation came from Minako Kojima. Completing the joy of the contest, the editorials came from Shang Jingbo. The participants liked what they saw and as soon as the problems were unveiled, they starting munching on them.
While everybody enjoyed the contest, the race to the top of the rank table was heating up with every passing minute into the contest. mikhailOK was the first one to make the mark on the contest with his accepted submission on AMIFIB inside the first two minutes into the contest. However, it was uwi, who sealed the contest with a score of perfect 5, with 0 penalties. The only other participant to have a score of 5 with 0 penalties was gerald, who stood 4th in the rank tables. Amid all that, we found a sight of sheer pleasure in anudeep2011’s 5th position. To have an Indian among the top 10 in a Cook-Off is a rare sight, but we would want you all to change that, just like Anudeep. Big congratulations to all the winners and participants.
Now, let us move towards the rank tables.
Now the Indian top 5:
The final stats for the contest were as follows:
Congratulations to all the participants and winners for taking part in November Cook-Off 2013 and making it fun.
Now, we move towards the December Challenge 2013, which is the final long challenge of 2013 and a great chance to strengthen your ACM ICPC preparations. So, mark your schedulers and do not forget to be there.
We hope you had a good time through our contests, however, if you have something to say, shoot it straightway at email@example.com. We love hearing from you people.
That is all from everybody here at CodeChef. Until next contest, adios people.
Like a big festival, the build up for the November Challenge 2013, had us all eagerly waiting for it. The contest was starting a day before the ACM-ICPC Asia-Kharagpur Site First Round Online Contest 2013, and two days before Diwali, so, the sparks in the air were perceptible. And, we enjoyed them all through the contest.
Starting on the festive backdrop, the November Challenge 2013 had the same warmth all through its course, which was much needed as the winters had just started peeking through the windows. The delicacies for the contest came from Bruno Oliveira, Divyanshu, Ivan Zdomsky, Sergey Nagin, Sokol Kostya, Tuan Anh, and Utkarsh Lath, and to test them we had Tom Chen and Mahbubul Hasan. The editorials came from Shaleen Sharma, however, not all of them. We tried to get them all, but we could not. You can read all about it here and can take up the responsibility.
Like the festive fireworks, the contest lit up from the very first day, and continued to be so, all through the ten days. The names kept changing in the rank tables, and while there were some familiar names in the rank tables, we saw some new ones too. So, let us introduce you to the final names on the rank tables, as our winners.
Firstly, the Global Winners:
Now the Indian winners:
It’s time for our little geniuses from Schools. First, the Global Top Five School Students:
Now, the Indian Top Five School Students:
Let us move on to our special achiever category, featuring top three Global and Indian users having highest scores for the challenge problem, other than the users.
The Global Top Three (other than winners):
The Indian Top Three (other than winners):
Now, let us have a look at the final stats for the contest:
We love seeing them numbers go up with every contest. And, while they are stunning to look at, they are just telling a part of the story, which here is much more than those numbers. Therefore, let us we all come together and beautify that picture. We have always cherished hearing from you guys, so keep sending your good wishes, feedback, and suggestions at firstname.lastname@example.org.
We hope you are all ready for chills of the impending December Challenge 2013. Hope to see you all there.
Till next time, adios from CodeChef
Before we proceed any further with this post, it is only fair to apologize for the prolonged delay in putting it up (and for some other posts following this one). So, a big Sorry to you all. There are several factors accountable for the delay, but we will not be discussing them. Instead, will come straight to our fifth edition of the Lunchtime, the October Lunchtime 2013. With every passing Lunchtime, we are getting one-step closer to our ultimate goal of having school students take up programming in their early age. That is one of many things that had us look up to the contest on every last Sunday of the month.
Seeing the young programmers from across the globe battle it out against each other, is a sheer sight of pleasure. With October Lunchtime a familiar name from our long challenges, Vineet Paliwal, made his debut as the problem setter and editorialist for CodeChef. Welcome aboard Vineet. Accompanying Vineet on the problem-setting bench was Roman Rubanenko, again a familiar face. And adding extra flavor to the contest was Sergey Kulik, with the Russian translations for the problems. With all that, the only thing missing from our October Lunchtime was the pinch of action, and that was added as soon as the contest started.
The participants started munching on the problems right from the initial stage of the contest. And as we went on with it, the young programmers seemed in a bit of hurry in their quest to the top. With some familiar names atop the rank list, and few others crawling towards the top, we felt warm and contented. As it was the initial signs of a new crop of programmers who will go on to become the pros of tomorrow. We will be alongside you all to see you blossom as great programmers and will provide all necessary guidance and support needed to make that happen.
With that, it is time to introduce you to the next big things through our October Lunchtime 2013 rank list.
If we have to go by the contest stats, the stay atop the rank tables is not going to be a cozy one. You do not believe us; have a look at the contest stats:
A big round of applause for all the participants, who are going to make life tough for them.
A heating up contest is a bright sign of a great outcome, and that is what we are expectant of from our Lunchtime. Therefore, we express our gratification towards each and everyone who contributed for making it a successful contest. We hope to get your constant love, and support for all our future contests.
If you have feedback, suggestions, or anything you want to say do write in to us at email@example.com.
We will be back with more contests, but for now, it is Good-bye from us all.
17/10, morning assembly time at City Montessori School (CMS), Lucknow, Gomti Nagar branch: A group of five hundred students from grade XI and XII gathered in the main auditorium. I go up on stage to explain all these budding students the concept of competitive programming. “Hello juniors” “Well, any guesses as to why I called you all as juniors?”… “Hmmm… as many of you might have guessed it, yes, I gave my ISC board examinations in this very same auditorium this year only”. “Now coming to a formal introduction, I am Karan Saxena, a First year Computer Science student at Sir MVIT, Bangalore. I am the Technology Head at Google Students Club and a freelancer at JAR (Just Android Resources) – India’s first all Android magazine.”
I then go on to ask them the next question- “What is a code?” I am expecting some enthusiastic answers but my hopes are soon dashed to the ground as only two hands go up. Nevertheless, I call one of them up on stage to answer. “Code is a small part of a program” “Correct. But don’t you think that’s a very dull kind of a description?” I then give them an intuitive definition of ‘code’- “Code is Logic. It means understanding the process and making it simpler. It is converting simple day to day tasks into mathematical terms and symbols”, I explain. I then show them the video created by CodeChef. Next, the obvious question is ‘Why should I code?’ or ‘What kind of people should learn coding?’ For the answer, I show them the 5min version of Code.org video.
After these two videos, I go for an example of ‘Binary search’. Over the next few minutes, I explain them ‘Binary Search’ from grass-root level with the help of a presentation. Then I announce that I have a twitter sticker and whosoever will give the correct complexity of binary search will get it. In the intermediate time, I explain them the definition of complexity. A student comes up and gives a correct answer as O(log N). I see a puzzled expression on the faces of students. I then intuitively explain them how log N came and that log is with base 2 and not 10 or ‘e’. Over the next few minutes, I go on to explain them that how India is technologically progressing but it is nowhere when it comes to competitive coding. I tell them that the only solution of this problem is to start early, and the way to start early is to practice and participate as much as possible. I then explain them what is ZIO/ZCO, IOI and ICPC. I tell them that nobody has ever achieved a gold medal in IOI. I explain them about ‘CodeChef Go for Gold’ initiative and ‘CodeChef Lunchtime’ programming series and that they should start participating in it as early as possible.
Watch the video of the assembly here: Karan Saxena, introduces CodeChef to students from City Montessori School, Lucknow, India
Wrapping up the session, I invite the interested students to the computer lab where they can have a hands-on session and ask their doubts. About 30 students turn up in the computer lab and have conversation with me over the next one hour. It was nice to see the enthusiasm with which they put forward their queries. All of them left with a sense of satisfaction and eagerness to participate in the upcoming ZIO/ZCO.
Overall, I felt very satisfied with the session. It was small yet effective step towards promoting programming culture. I’ve done my class XI and XII from CMS only. It’s an outstanding academic institution and is counted among premier institutions in the country, but the thing I noticed during my time is that there is very less focus on programming, specifically competitive programming. Students are extremely brilliant here but only focus on science subjects and study computers only with point of view of examinations. I wanted to change this and hence approached the principal, Ms. Manjit Batra, who, gave me permission to conduct this session for the betterment of the students. She also allowed me to act as a mentor to the students and help them with their doubts and also to keep them updated with the contests happening. I’ve created a group on facebook where all the class XI and XII students can discuss their programming problems and solutions with other students from the same institution. All of them have my number and are welcome to call me anytime they feel necessary. I’m constantly in touch with all of them via the group. Many of them are participating in this year’s ZIO/ZCO and I’m hoping to get a good result from these students.
Lastly, I would like to thank the whole of CodeChef team for taking up this one of its kind initiative which will prove to be very useful for budding young programmers. I wish them a grand success in this endeavor.
As the time nears the declaration of the selected list of teams for the onsite, we think we must own up the mistake and issue an apology. We understand that there were some problems with the online round for ACM ICPC 2013 IIT KGP regionals. For those who missed it:
For the first issue, we investigated and found out that it was caused due to an un-optimised query that fetches you all the submissions of a particular problem in the practice section! We are in the process of fixing it, but we thought we should at least tell you what the reason is while the fix happens. To make up for it, we had extended the contest by another 10 minutes. We also eliminated all penalties for those who were affected by the slowness and ended up submitting the same solution multiple times.
The second issue impacted users much more. And we realised that we had goofed up, only after the contest. At this stage, we sat down and evaluated all the options to salvage the situation. We knew that we could not be fair to everyone from that point. No matter what we did from there, there would be one section who would be affected by this mistake of ours. Considering every possible scenario (including a re-contest), here’s what we decided to do:
Change the test data such that the solutions which solved the problem without sorting the output list also passes. This essentially also meant that the problem no longer required a DP solution to pass and became easier than what it was intended to be. We rejudged all the solutions which had not passed during the contest for this problem with the new test data, leaving aside those that had passed. This resulted in more teams now solving the problem.
Some of you are bound to feel (especially those who wasted a lot of time on this problem) that this isn’t fair. We know it, but there is not much that we can do about it. We screwed up, and we’re really sorry. Here are the other options and an explanation of why we took this approach:
While we acknowledge that we have goofed up and we regret it beyond what we can put across, we also think, that not being stuck on a problem, you are unable to solve, is among the many things that can propel your team to be a good ICPC team. A team of three wasting all their time on a single problem can cause a lot of frustration, but then that should not warrant wasting the time of so many other teams that have done well and also learnt to deal with such situations and got more efficient.
Some people will undoubtably feel like we should’ve taken one of the other approaches listed above. We’re sorry, we cannot do that. Don’t hate us. We know we have goofed up. And we did try our best to be as fair as we possibly can in the given circumstances. We wanted a good fair contest as much as you all did. We did receive some positive feedback on the problems being good as well. We have also published the editorials for the problems. We did try to do as much as we can.
For those who will not be able to make it to the onsites due to this mistake of ours, we sincerely apologise. We know, nothing can make up for it. But there is only so much we can do. Please do not get demotivated and do not give up. Please practice hard for next year. We will be around to help you all in your preparations. We assure you, that we will be extra careful next time around. We are sorry.
Nothing give jitters to the programmers as much as a big programming carnival. And if you are a programming enthusiast in India, that time for you is now. With ACM ICPC India regionals fast approaching, everybody is busy with giving final touch to their preparation, and perhaps packing bags, by now, for the regionals. And we wanted to help our young friends break out of their nerves and put all their preparation to test, with our October Cook-Off 2013.
While our Mega Cook-Off was set to test the preparations of the ICPC aspirants, it also brought the opportunity for the top 75 Indian Students, as opposed to 50 last year, to have their ACM-ICPC expenses reimbursed. Yay! The details about it can be read here. With all that we were all set for the contest, which promised some tough competition and a lot of fun.
The contest began with first accepted submission on Polo the Penguin and the XOR inside the first ten minutes of the contest. The quick first few accepted submission, indicated a free flowing contest, which was a pleasing sign as it meant that the preparations were good. However, there were instances when the contestants found themselves tangled in problems, especially the ones who tried to find some luck in Polo the Penguin and the Lucky String. It was only after an hour that EgorK cracked it. However, by then three other problems were already seeing accepted submissions, frequently. The problem set was nicely balanced to let the users have fun and test them without causing any turmoil. And it was acknowledged by the contestants and our fellows on the problem setting panel alike.
As the contest progressed, the number for participants and submissions started soaring, indicating a good night for us all. The fight among the contestants (from India), was not only to be among the top, but also to finish up among the top 75 students from India to have their ACM ICPC travel expense reimbursed. And if the numbers are to be believed, they all fought belligerently.
Here are all the numbers to let you decide.
Let’s say hello to the the top performers, Indian as well as Global:
Firstly, the Global:
And, now Indian top five:
The October Mega Cook-Off 2013 was deemed as a warmup for the impending ACM ICPC India regionals. However, we wanted you all to chill, and just participate with all your heart and soul. And we hope you all did. There is still sometime before the onsite regionals and you shall be even better prepared for the onsite event, so All The Very Best from all of us.
Now, before we sign off, let us thank the people responsible for the nicely balanced problem set, which came from Vitaliy Herasimiv, the testing for that, which Tasnim Imran Sunny did splendidly, and the delectable editorials to celebrate the contest from Tuan Anh. The additional colors for the contest in the form of Mandarin and Russian translation came from Minako Kojima and Sergey Kulik.
And a big thanks to all you wonderful people for making it such a wonderful contest. We have always cherished your feedback and suggestions, so keep sending them at firstname.lastname@example.org.
Till next time, it’s adios.
See you at the contest.
We all have a preconceived notion about any competition where the big guns are going up against each others. It becomes easy for everyone to predict the outcome of the contest and more often than not, those prediction comes close to the actual result, if not all true. However, as soon as even a single big name goes missing from the participant table, the slot atop the rank table opens up for almost every participant. That is what happened with our October Challenge 2013. As soon as it was revealed that ACRush, djdolls, and mugurelionut will be on the problem setting bench, there was a sense of relief among the participants. And they all were set to give a shot at the top slot. However, the brawny kgcstar, was still there along with other seasoned campaigners including anton_lunyov, kevinsogo, stzgd, and others to ensure a stiff competitiveness in the air. And with that began our October Challenge 2013.
The October Challenge 2013 had a special flavor added to it in the form of Mandarin translations for all the problem statement. This made it the first multilingual contest of CodeChef, and for our native Mandarin speaking friends, made it easy to understand the problem statements. The Mandarin translation came from Minako Kojima, so a big thanks to her. The contest opened to an action packed weekend, with Lira getting help from all quarters. While Helping Lira made life easy for the participants, Three-Degree-Bounded Maximum Cost Subtree, Fibonacci Number, and Kamehameha were putting the participants to a tough-yet-exciting test. And it’s good to see that they all came out with flying colors.
But who came on top? let’s see the rank tables and find out.
First, the global winners.
And the Indian winners:
Now, let’s move on to our special winners.
Firstly, the young brigade from schools:
And now, the top three Global and Indian users having highest scores other than the winners.
The very first weekend of the contest made it apparent that everyone is going all out to sharpen their programming skills ahead of the impending ACM ICPC regionals, and by the end of the contest we had the numbers reflecting that. Here are those figures for you.
With ACM ICPC just around the corner, it was great to see the number of participants go up in the final stages of the contest. But the real spice was added in the beginning of the contest in the form if the challenge problem scoring changes, which meant that even after the contest is over, there will be not a clear winner until the submissions of the Challenge Problem are being re-judged. This kept a lot of people on the edge of their seats even after the contest was over, including us. Though, the rank table did not changed drastically after the re-judging, but we did saw some shuffle of positions atop. Did you observed any change in your position in the rank chart? Do share it with us. Also let us know what you think of the changes that were brought into effect from October Challenge.
With problem setting panel featuring Tom Chen, Bruno Oliveira, Ivan Zdomsky, Kaushik Iska, Mugurel Ionut Andreica, Sergey Nagin, TianCheng Lou and Vitaliy Herasymiv the problem setters bench for the October Challenge had some real masters of the craft penning down the problems for the contest. The testing of all those problems was done by ShangJingbo, who ensured that the problem set is balanced enough to test the participants and to let them enjoy the contest the fullest. The elaborate editorials came from Ajay Kumar Verma, who has all the expertise required to draft well understandable editorials. In the end all their efforts were appreciated and accepted with lots of love from participants all over the globe.
That sums up the tale of the October Challenge 2013, which saw some twists in rules, some new names in the rank tables, and most importantly gave everyone fun and exciting competition. We will be back with the tale of October Mega-Cook-Off 2013. But till then, why don’t you tell us what you thought of the October Challenge?
So, send us any feedback, suggestion, or query you might have in the back of your mind at email@example.com.
Also, coming your way is the ACM ICPC Asia-Kharagpur Site First Round Online Contest 2013, we hope you are ready for it.
But till the next big blast, it’s adios from everyone here at CodeChef.
Following your discussions on our forum under “Changes from October Contest” and “Separate final test cases for Challenge Question,” starting from October Challenge 2013, after a lot of deliberation with our problem setting panel, we will be making a few changes in the way the scores for the challenge problem are being calculated:
This will be applicable for long challenges starting from October Challenge 2013. However, these are only provisional and we may change them based on the feedback that we receive from you guys.
How do these changes affect me?
In two simple ways:
Whatever you think of the above mentioned changes, do share with us.
Gear up for the October Challenge 2013 with a pinch of new rules to spice it up.
All the best.
The September iteration of our Lunch Time programming series did not see the same notable participation, as our August Lunch Time did. And it makes us a bit sad, as we want more school students to take part in it. Now, there can be various factors behind the comparatively low participation. But if you have any specific reason which is stopping you to take part in our contests, like tough problem set or the timing of the contest, feel free to let us know. We will try and make sure that it is addressed.
We are sure that all those who did not participate this time will show up in the next contest. Also, if any of you did not participate because you did not do well in the last contest then it is our sincere request to leave it behind and move on. It is only when you keep on participating, you will master the art of programming. We believe, success just happens – really. No one can prepare you or teach you to be successful. It is something that you will have to learn on your own, and master on your own, pretty much like programming. The more you practice and participate in such contests, the more you will learn about it.
So, get up, brush yourself up, for the next October Challenge 2013, which is just around the corner. Put the fret of the past contest to rest and start afresh. We are sure all you young geniuses have incredible potential and that we will see you in our next round of contests, let alone the Lunch Time. By the way, the October Lunch Time 2013 will be held on October 27th, 2013 at 11:00 am.
Now, let’s congratulate our friends in the rank tables of September LunchTime 2013.
And now, the total stats for the contest:
A big congratulations to all the participants for their splendid performance in the contest. You all are awesome.
The numbers, this time around, definitely were a bit on the lower side, but that, together we all can change. And that we should change. The bigger the contest, the healthier will be the competition, and the more fun we will have. You see its a win-win situation for all of us. So, do not hold yourself back, get up and join the league of extraordinary programmers from across the world.
We hope to see all you brilliant young minds, in all our contests. So, starting from the impending October Challenge 2013 we hope to see more and more of our school force taking up the challenges and paving their way up the programming ladder.
If there is something that you want to share with us, your feedback, suggestions, or your tiffin box, we would love to have them. So, keep them coming at firstname.lastname@example.org.
Till next time, TA-TA.