Slow_But_Determined's blog

By Slow_But_Determined, history, 5 years ago, In English

Greetings Codeforces community!

CodeChef’s May Lunchtime sponsored by ShareChat is just around the corner and you are all invited to participate. This is not only an opportunity to get some practice and improve your coding skills, but also a chance to improve your rating!

Team CodeChef is also seeking problem ideas for our upcoming contests! If you think you have an idea that will make for an exciting contest problem, then send it to us using this form: https://www.codechef.com/problemsetting/new-ideas. Come and take your first step towards becoming a CodeChef problem setter!

ShareChat — India’s fastest growing social network is inviting participants of the Lunchtime to come apply for exciting work opportunities. Job opportunities are open to programmers across the world and internship opportunities are exclusively aimed at final year B.Tech students who have already been placed and looking forward to gaining startup experience. Visit the contest page for more details.

I hope you will join your fellow programmers and enjoy the contest problems. Joining me on the problem setting panel are:

Contest Details:

  • Start Date & Time: 25th May 2019 (1930 hrs) to 25th May 2019 (2230 hrs). (Indian Standard Time — +5:30 GMT) — Check your timezone
  • Contest link: https://www.codechef.com/LTIME72
  • Registration: You just need to have a CodeChef handle to participate. For all those, who are interested and do not have a CodeChef handle, are requested to register in order to participate.
  • Prizes: Top 10 Indian and top 10 Global school students from ranklist will receive certificates and CodeChef laddus, with which the winners can claim cool CodeChef goodies. Know more here: https://discuss.codechef.com/t/how-do-i-win-a-codechef-goodie/7344. (For those who have not yet got their previous winning, please send an email to winners@codechef.com)

Good Luck!

Hope to see you participating!!

Happy Programming!!

UPD: Unfortunately the contest is going to be unrated due to server issues.

UPD2: Congratulations to the top 3!!

DIV 1

  1. isaf27
  2. uwi
  3. amnesiac_dusk

DIV 2

  1. Geothermal
  2. Sugar_fan
  3. CSHwang

UPD3: The editorials of first 4 problems are ready and will be posted soon. The editorials of other 3 problems will be posted tomorrow. Meanwhile, you can go through the Author's notes for those problems here.

UPD4: All editorials have been posted.

| Write comment?
»
5 years ago, # |
  Vote: I like it +20 Vote: I do not like it

is it rated ? still

»
5 years ago, # |
Rev. 2   Vote: I like it +36 Vote: I do not like it

I am not able to open any submission page or even main page for that matter. Is it just me or everybody is facing issues?

»
5 years ago, # |
Rev. 2   Vote: I like it 0 Vote: I do not like it

its rekt now. pages are not opening for me :")

PS: its working okay now, so maybe keep it rated.

»
5 years ago, # |
  Vote: I like it +46 Vote: I do not like it

I am sorry, but it doesn't make sense to make this round rated with these testing issues

»
5 years ago, # |
  Vote: I like it +12 Vote: I do not like it

The contest is unrated if anyone has missed the announcement!

»
5 years ago, # |
  Vote: I like it +3 Vote: I do not like it

So, how to solve 'Intervals and Intersections' in complexity better than M^2?

  • »
    »
    5 years ago, # ^ |
      Vote: I like it +5 Vote: I do not like it

    You can go through the Author's notes for last 3 problems here.

  • »
    »
    5 years ago, # ^ |
      Vote: I like it +5 Vote: I do not like it

    try to formulate DP by breaking up the formula into pieces and taking prefix sums. See if u can find a common optimisation pattern there.

»
5 years ago, # |
  Vote: I like it 0 Vote: I do not like it

Auto comment: topic has been updated by Slow_But_Determined (previous revision, new revision, compare).

»
5 years ago, # |
  Vote: I like it +4 Vote: I do not like it

Please move the problems to practice.

»
5 years ago, # |
Rev. 2   Vote: I like it +44 Vote: I do not like it

You are Indian superstar coder (meaning 3 stars on Codechef)

@

Decide to write Lunchtime

@

Nobody is able to submit tasks, but you didn't notice it as you haven't tried to yet

@

Round is announced unrated, almost everybody leaves the contest

@

You continue to the end of the contest and as all strong contestants left you luckily end up in top N, where N is your Codechef rating, which is your best performance

@

"Why is it unrated? It's my best performance!!!"

  • »
    »
    5 years ago, # ^ |
      Vote: I like it +27 Vote: I do not like it

    antontrygubO_o, you are absolutely correct from your point of view. I mean from the point of view of someone outside India studying in one of the most top-notch institutions in the world.
    But unfortunately, your sense of humour is not appreciated.

    You are Indian superstar coder (meaning 3 stars on Codechef)
    


    We Indians, have an education system which DOES NOT ALLOW any scope of creativity, talent expression, or anything other than rote learning (except homeschooling). (I won't deny that the situation is getting better with time, but the progress is too slow.) Moreover, the focus on coding in Indian schools (at least where I stay) is very weak, and as a result, many school students in India don't even know what cometitive programming is. So if you are a division 1 coder as an Indian school student, you are really good, at least compared to your peers. For colleges, if you are not in one of the IITs or some other tier-1 colleges, life as a competitive programmer is hell for you as you simply DO NOT have any coding environment or someone to look up to as a coder. So unless you are super-intelligent or extremely hardworking, competitive programming is just a dream for you. So just mocking people who are not even one — tenth as good as you are may seem to be fun, but being on the receiving side isn't.

    You continue to the end of the contest and as all strong contestants left you luckily end up in top N, where N is your Codechef rating, which is your best performance
    


    The contest was absolutely fine for most people in the latter half, so if someone didn't notice the announcement, it dosen't come as a huge surprise. Thus, making the contest unrated instead of extending it may seem to be controversial.


    PS: Codechef has been making sincere efforts to improve the competitive coding scenario in India since the last decade and has been appreciably successful in its endeavours till date.

    PPS: A newbie answering a red coder dosen't seem very good as I don't think I am qualified enough to reply to you. But I just made you aware about the actual scenario of cp in India and why your sense of humour is not appreciable.

    PPS: Many people may find this comment controversial. So you are free to downvote it if you want. :)

    Peace :)

    • »
      »
      »
      5 years ago, # ^ |
        Vote: I like it +1 Vote: I do not like it

      I don't know of the Codechef situation as I don't participate there but I disagree with almost all the points you mentioned in second paragraph.

      Who is stopping you to take part in Olympiads, JEE is certainly not a rote learning. It does require creativity.

      Coding environment is very over-rated thing and many people(especially Indians) use it as a excuse if they are not good at it. You have every resource you need to be good at these regular online contest.

      • »
        »
        »
        »
        5 years ago, # ^ |
          Vote: I like it +11 Vote: I do not like it

        I never mentioned JEE. But since you mentioned it, JEE is based only on PCM and does not require an iota of knowledge of coding. Except CMI and IITH, I don't know any other Indian college which offers admission based on your CP skills. Even those two colleges offer admission only if you clear INOI in class 12, which is a very very limited number of students. Thus most students think CP to be just a waste of time as it won't help them anywhere in the near future.
        As to coding environment, I think either you are from the IITs or you don't know the situation of tier-4 or tier-3 colleges in India. You don't do CP if you don't know WHAT is CP.

        • »
          »
          »
          »
          »
          5 years ago, # ^ |
            Vote: I like it +3 Vote: I do not like it

          I was answering your statement about Indian education system does not require creativity. JEE does not directly relate with CP but performing good in JEE is a good indicator how well one can do CP, That's why Indians who are good at it have done well in JEE.

          No, I am not from IIT, I am in 11'th class and I'm preparing for JEE and many maths concept I learned have helped here in CP. Preparing for any high quality competitions increases your brain capabilities.

          Why you want everyone to do algo contest?

          Sorry, I don't think CF is a platform to discuss these things. We can now stop it and think what one wants to.

          • »
            »
            »
            »
            »
            »
            5 years ago, # ^ |
              Vote: I like it -16 Vote: I do not like it

            'Performing good in JEE is a good indicator how well one can do CP'. Please don't say this. I am coming last in my jee coaching.

            'Many maths concept I learned have helped here in CP'. I'm guessing this is just a little of combinatorics which in jee only requires PnC. If 0.0000001% of jee stuff helps in cp, u can't just say jee is helpful for cp.

            • »
              »
              »
              »
              »
              »
              »
              5 years ago, # ^ |
                Vote: I like it 0 Vote: I do not like it

              'Performing good in JEE is a good indicator how well one can do CP'. Please don't say this. I am coming last in my jee coaching. Performing good in CP is not a good indicator how well one can do in JEE.

              I believe solving JEE problems increases abstract thinking which is helpful in CP especially for problems which I get in contest for my rating range.

              • »
                »
                »
                »
                »
                »
                »
                »
                5 years ago, # ^ |
                Rev. 6   Vote: I like it -7 Vote: I do not like it

                NO. I am a top 100 JEE ranker and have done pretty well in olympiads too, so I can guarantee you that JEE and Competitive coding have little common in them.JEE is much more rote learning based and doesn't need/help build the creativity needed for CP. Even olympiads are mostly based on manipulating formulae and require an extremely different kind of intuition compared to CP. So your logic is incorrect IMO. And yeah he is right about coding culture in India. In most schools except for certain metropolitan cities computer science means just memorising a language and its basic syntaxes like pointers/arrays/classes etc. I used to hate programming in school because of the way it was taught there. And no-one in my town never even mentioned CodeChef/Codeforces etc. It is not a excuse but the truth.

    • »
      »
      »
      5 years ago, # ^ |
        Vote: I like it +11 Vote: I do not like it

      silent_sky, thanks for providing your view of the situation! To begin with, I sincerely believe that your color should not matter when responding to someone's comment.

      I get that my comment might be seen as simply being negatively aimed at the Indian cp-community. I might have added some exaggerations to make it funnier (doubt that worked well though). However, I didn't mean it that way. With no doubt, India is one of the top CP-countries and the Codechef platform has shown amazing efforts and progress in making CP more accessible and enjoyable not only for people in India but all around the globe.

      My comment was mostly about people who judge whether contest should be declared rated or not from some personal arguments (as "I scored high for the first time, and it's not rated? It's demotivational!"), not from objective reasons. The first few sentences were merely to describe why the results of the round weren't objective: One my friend gave up the contest as he wasn't able to load even a single task's statement; I gave it up after unsuccessful attempts to submit the problem, even before it was announced unrated (though probably giving up contests in such a manner isn't a good thing to do). I am pretty sure that many more contestants left the contest after, not even because it was announced unrated and they only care about the rating, but because they were just annoyed by the impossibility to view and submit tasks. Yes, I can't judge how many contestants left, but I am pretty sure that the average performance of participants who continued got higher than it would be if no issues took place.

      I completely understand how one might have missed the announcement, it was also possible not to notice any issues with the contest at all during it. The thing I sincerely don't understand is why people write comments "Why unrated?" when the announcement was done in the first hour and the technical issues by no doubt took place. We should stay objective after all

      • »
        »
        »
        »
        5 years ago, # ^ |
        Rev. 3   Vote: I like it +10 Vote: I do not like it

        antontrygubO_o, thank you for understanding that although you didn't mean it, your comment was framed in a way that it can be misinterpreted. Also, I do understand that even after making the contest unrated in the first hour itself, there were people who demanded it to be rated again (Even I was upset after learning that the contest was unrated as I did not notice the announcement and continued with it till the end :p). That being said, IMHO, declaring the contest unrated was the best and the most fair way out.
        Have a nice day ahead. :)

    • »
      »
      »
      5 years ago, # ^ |
      Rev. 2   Vote: I like it +4 Vote: I do not like it

      We Indians, have an education system which DOES NOT ALLOW any scope of creativity, talent expression, or anything other than rote learning (except homeschooling).

      Every somewhat-functional mass education system tends towards that (all you can say is that India tends more to the extreme), it's the cost of having to fit all kids into one system. The modern education systems that don't do that are also completely disregarding rote learning (going to the other extreme), teaching kids to be special snowflakes and giving out participation awards. The only way encouraging talent expression works are custom approaches to a small number of kids — homeschooling fits here.

      An education system can be broad, not boring or good at teaching lessons that stick. You can't pick all three, only move on a scale. When you want everyone to learn by having fun, you lose any semblance of discipline. The GRIND MUTHAFUCKA GRIND approach is boring and insufferable. When you give top quality education, you find out that you can only reach few kids.

  • »
    »
    5 years ago, # ^ |
    Rev. 2   Vote: I like it -54 Vote: I do not like it

    Chutiye,maadarchodh,ijjat me reh,jab tujko Indian logokaa condition nhi pata toh kuch bhi mat bol. Apna rating apne gaand mai daal aur nikal le. Tere jaise bachpan se humlog coding nhi karr rahe. Humaare log ek saal coding karke red bante hai, tumlogoko je jaise 5-saal nhi lete maadarchodh,behenchodh.

    Fyi, there were 3000+ participants, which is more than usual, which means many people didn't leave the contest including topcoders, so do your homework first and check the ranklist first. The top rankers are all 6-7 starers. And if even if many of them leave, you don't have a perfect estimate of how many of them left so better keep your mouth shut before dragging 'India' unnecessarily to this topic. Or else you'll face hard time from us.

    • »
      »
      »
      5 years ago, # ^ |
        Vote: I like it +26 Vote: I do not like it

      I really feel ashamed after seing such kind of behaviour of Indians online.

»
5 years ago, # |
  Vote: I like it +5 Vote: I do not like it

Editorials for all problems have been posted at discuss.codechef.com. Refer editorial for problem PROBCODE as discuss.codechef.com/problems/PROBCODE.