Hello Codeforces!
I'm here to announce the release of MathMash!
It's a Math contest platform pretty similar to Codeforces in contest structure. Each user is given an initial rating of 1000 and it's updated after the end of a contest that the user participated in, based on his rank in the contest. It also has a community which I put a lot of effort into. The community is made up of mini communities: Any user can create his own forum, add admins and start a community himself.
I also tried to add some facebook flavor to the site. You can make friends or follow other users. Whenever any of your friends posts or comments anything or someone upvotes your post/comment you'll get notifications.
I posted about the basic functionalities of the site in this MathMash post.
So today I'm hosting the first contest of the site. The contest consists of 7 problems to be solved within 2 hours. It'll start on UTC 2:00PM today.
You're all invited to join the contest. Hopefully we will fun!
It's awesome.
Could you explain how the contest will work? The problems are project euler style? Or IMO style? I couldn't clearly find it from the blog post.
They are project euler style. You need to input the answers to the problem. Similar to this problem.
Any submission penalties?
At the moment, no. But I'm open to any new suggestions. Should we assign each practice problem some points? Or maybe solving a practice problem increases user reputation?
But I've set a limit of
20submissions per problem in a contest, because otherwise anyone can get a problem right by submitting enough times. I'm not sure if setting a limit is the best way to deal with it. Again I'm open to your suggestions. Let me know if you have any other ideas.But contests do have time penalties. Problem no.
xcosts2^xpenalty for each minute passed. For example, suppose, problemAcontains100points. Then if you solve it correctly5minutes after the start of contest, you'll get100 - 5 * 2^1 = 95points.How can I know if my answer to a problem is right?
It'll show you an "Accepted" message. Try solving this problem for example.
My Submit button doesn't work.
Google Chrome Version 64.0.3282.186 (Ubuntu)
UPD: Oh, my bad, didn't see where I need to type the answer.
Are the problems supposed to be solved with or without the help of programs?
https://www.mathmash.org/problem.php?prob=2 doesn't require programming but the constraints allow for people to write programs to find the solution.
Practice problems are just for fun, so if you enjoy coding the problems you're welcome to submit the output of your code. But writing programs for contest problems are not allowed, as it takes effect into your ratings.
As contests doesn't require any programming skills, why not to post it on AoPS? :)
How can you prevent cheating?
As cool as a2 + b2 = c2 theorem. :)
Seriously? You don't know any cooler theorem? :\
Only Pythagoras is real shit. Tell me yours.
Pythahoras theorem, is, shit? How you dare?
Dude, U don't understand the pun.
a^n + b^n = c^n doesn't hold for n>2 :P
problems not working
Now there is a second postpone. Edit: and the third one comes
It seems that problem D has wrong statement. Sets actually can be empty.
Providing such contests on math is a good idea (which has good sides of projecteuler and mathfights and just projects the concept of a big live competition onto mathematics), thank you for realizing it. Now I have several questions:
Are you going to make it a big platform for a huge amount of people? I mean, you can do it just for fun and not care about server's performance, thus making all following questions not having any sense.
Are you going to prepare contests by yourself? If no, are you going to pay to problemsetters? I'm not sure how it should be organized since preparing a math problem requires much less effort than for a programming contest.
Will your platform support pm's and questions during the contest?
Also I can prepare a couple of contests for it for free, I want this platform to attract more people.
Yes my goal is to grow it into a big platform and The pm's and questions feature won't take much time to add.
But the thing is that I had to put some good effort for the last 5-6 months to bring it into the current state. And I cannot really grow it now into a big enough platform all by myself. I could really appreciate some collaboration from others.
And I can't really pay the problem setters for much long as I'm a student myself and even the server costs really hurt. Although it could be a short-term solution till we find some other way.
A lot of thanks for your kind offer to prepare some contests for the site. I would be really happy if you could do that.
And I don't really know what to do about coding the problems. The only option of judging math problem results appears to be taking inputs and most of such math problems are vulnerable to coding.
Another idea a person gave me is to just take the proofs/solutions during the contest and hire some graders to grade the solutions later, after the contest ends.
Checking the solutions by eyes like in mathematical olympiads seems very difficult if, for example, ~500 contestants take part. Even if there will be a judging committee, it'll be very hard to check all solutions according to the criteria and not to miss anything.
Coding, however, doesn't look like an issue to me. It's just a projecteuler format. Moreover, it's about combinatorics, but geometry, calculus and many other branches look safe.
I think the idea of your webpage is very nice and I hope it grows, I have some comments to make.
The first is that I also want to volunteer to make some problems( for free of course), I am not as smart as many people who could volunteer but I have a good base( you can check my IMO results) and I am working on it.
Also about the whole cheating by coding I recommend you look at the Online Math Open problems( website: http://internetolympiad.org/pages/11-omo ). The harder problems are very interesting and also designed by very smart people so that it is very hard to code them. It takes a lot more effort to make problems of this kind but I have already invented some.
Lastly, I believe you should definitely make an AoPS post about the website, you could get a lot of participants and even some volunteers.
Of course you can help us set the problems. Your IMO results are a lot impressive too.
Although you won't be able to participate in the contests that you set problems for. Kindly PM me if you're still interested.
How to solve D and E?
D: Let's say that 1 goes to set 1, 2 goes to set 2. After that we construct sets number by number, for each number we have only 2 possibilities (it must go to any set without previous number), therefore answer is 2^18 (note that we counted the case when one set is empty).
E: We can note that P looks like ax^3 + bx^2 + cx. Then we can find a couple of values of P and interpolate.
It's more convenient to look at P's roots in E
For D, give 1 and 2 to any two sets and then it's easy to prove that each number can go 2 sets, so answer is 218 if we count empty set, or minus 1 otherwise (there is a little mistake in statement).
For E, write polynomial as an * xn + an - 1 * xn - 1 + ... + a1 * x + a0 and after some calculations you will get n = 3. Also it is easy to get P(0) = 0, so P(x) = ax3 + bx2 + cx. Write it in given equation and again after some calculation you will get
.
Thanks you all)
Problem F solved than problem B while it was much harder. It was on my math quiz at school and I knew answer by heart, it's 615. Is there any way to prevent coding for contest? I mean it is really easy to write 5 line and get answer immediately while solution of problem is not that easy.
Can we upsolve contest problems? And how regular will contests be arranged? I really hope it grows and becomes popular. And don't let it die as the BdMO forum did :p
Yes, I did so since I missed the round. But there is no such features as "virtual contest".
I did not get a confirmation mail, I checked the spam folder.
I have this problem too.
I manually verified the pending accounts. You can try to login now. If you are still facing problems, kindly comment here.
Doubt cleared.
The problems aren't supposed to be solved by coding. See this comment.
Oh I see. Thanks!
Excellent initiative ! I love it ! I always wanted a website like this !
Will editorials be published ?
The editorials have been published here.
[user:DrSwad]I did not get a confirmation mail, I checked the spam folder.
Can you kindly PM me the email/username you used? I'll assist you further in private messages.
There's a small typo at the difficulty of a problem. It says difficulty: East
Fixed. Thanks for pointing it out.
Any plans for more round anytime soon? DrSwad
I loved the contests here!
I hate to say it. It breaks my heart :( But I fail to see how I can continue MathMash anymore. Let me state the reasons, I'll be glad to hear any suggestions to resolve these problems.
The first and the most important problem I'm facing right now is contributors. Right now, I have exactly 0 contributors excluding me. During the last year, I was a college student, all of my friends were college students. We had a lot of free time to practice Math Olympiad problems and do extracurricular activities. So, they helped me set up the problems, write the editorials, administrate rounds etc. But now, most of them have gone abroad to study in universities and understandably they'll be very busy. And even if I'm very busy too with ICPC practice and studies, I'm willing to put my best efforts in MathMash. But, in a more practical sense, there's way too much work in maintaining a whole community, to be handled by a single person.
The second reason is, this site feels broken in every feature I use and the UX is terrible. The loading time is insane. It needs a rebuild. So, I planned to redevelop the whole thing more carefully. But this site is much more bigger than I anticipated. So, I've spent around 4 months developing the new version, where initially I though it would take mere weeks. Anyhow, 75% of the development work have been done and I'm still willing to finish it. But the thought of the first point implies that, even if I sacrifice a lot of my cp practice time developing this site, in the end I might not even have enough helping hands to set any more rounds. It is quite discouraging and it seems like a very bad risk to take, seeing that I'm improving much faster now with full time cp practice.
Finally, the cost to host the site and to keep the domain is considerably high. Sooner or later I'll have to find some way to get money to at least maintain the site, let alone profits. The most probable way I can see, is to ask for donations. But with no admins or developers excluding me, I fail to see how I can take this site in a decent enough state where users will be satisfied enough to provide donations.
But, even if the site is taken down, I'll upload all the problems with their solutions somewhere so that anyone can still practice using/provide reference to them.
Nevertheless, the support from the users have been such mesmerizing. It has been incredibly fun to prepare the rounds and see everyone enjoy my work ^_^ I'll save the codebase and database safely, so that if ever seems possible, the site can be made live again. It's just too much awesome to let go of forever <3
It feels sad to read this. But, first I would thank you for creating something as cool as MathMash — a very handful people actually passionately pursue building out their ideas. Coming to problems in hand :-
I hate to talk about monetization or so but if we can solve it, we can solve the first two for long term. I am curious to know source of income for Codeforces/atcoder apart from sponsorship? It will be awesome to see Project Euler type contest getting mainstream with championships, etc but practically speaking its a niche with almost no direct benefit (like many do CP for interview) so I expect active participation in these contest to be lesser than CP sites. So, monetization shouldn't depend on quantity of people but quality. In my limited experience, PE folks are of a pretty different breed and become great at solving hard problems in relatively shorter span of training (maynot be true? I haven't met a lot of people to generalize). If it is so, can we become like Hackerrank for small set of companies who require hard problem solvers and/or math/programming? Can we explore other routes to create revenue?
If we can come up with something, I will be more than happy to set 5-10 contests with some help to keep it going. Also, you can open-source so other people can contribute remaining 25% of your upgrades? I mentor students in RGSoC org scalability4all, we can move your project there to get more helping hands if it is needed.
It will be interesting to hear perspective/experience from Golovanov399, zeliboba, triveni, jtnydv25, usaxena95, rng_58 and others for their take on these problems?
I agree that making a good platform and constant preparing rounds requires a lot of efforts, and I understand DrSwad well when he says that he is not ready to do this all alone, no matter how nice it was to take part in these contests.
I cannot help with platform and other technical stuff, I will donate money if there will be some crowdfunding campaign or another public donation request, and I think I can make a couple of contests. However, I found out that it's very easy to overestimate abilities of self to create a good problemset. Honestly, when you, phpduke, say that you are going to "set 5-10 contests", I tend to think that either you don't imagine what it takes (the variance of "5-10" is quite big, you know), or you have really a lot of problems on different topics with not guessable, progrrammable or wolframable answer, not from the last imo/imc/vjimc/cf blog, or the main part of that sentence is "with some help". That being said, I have some bank of problems, I'm ready to suggest one or two problemsets, I'm not going to do this regularly, I'm unlikely to invent new problems, but I can change already existing ones so that they involve one idea more.
The most important thing I'd like to say is that in my opinion one's health is worth more than joy of 40 people solving problems for 2 hours, so DrSwad, don't reopen mathmash if you feel that this will cost you too much stress, better find enthusiasts and redistribute the most hard and important tasks between them or drop it at all.
I have around around ~200 prblms from past rounds of Gordian Knot, that happened 5-6 years ago. While preparing for math olympiad, I competed in tech fests from ample of Indian univ with good problemsets. Dependence on how many problems we can retrieve and be able to adapt key tricks/ideas is something I can't predict, which creates variance of "5-10" contests. The original prblms I created, took long hours and some took days so its obvious we can't set all contests with all new ideas.
I do agree with your last para, though I wanted to see if we can do anything about it before dropping it altogether.
Probably I could create one problem set per year. Also I could organize AIM Tech sponsorship of this project.
This offer is gold <3
@zeliboba That'll be so great, if made possible! ^_^ If things go well, it can resolve most of the problems and be a huge milestone for the community. I'll be ever grateful to you if MathMash can continue with your massive help ^_^
Should I finish developing the site, for you to see if MathMash is eligible for a sponsorship? I'm willing to put the necessary time if it requires. Or do you think, images of the new site design and current development state would be fine?
I'm so very excited with this new opportunity to keep MathMash going! ^_^ And a problemset from you can raise the quality of this site's content significantly. Eagerly waiting for your response!
Also, thank you so much phpduke, Golovanov399, zeliboba, trash.py for offering your help in setting up some problems ^_^ If MathMash does continue, I hope your help will stabilize the community for some time, that'll allow it to get interests from some long-time enthusiastic admins.
@phpduke I think the idea to open-source the dev codes is nice, if there are people willing to help finish it. I've been skeptical about it so far, since I had doubts if anyone would be interested in contributing to it's code. But there's no harm in uploading it :) So I'll add it to my public github repository. @zeliboba, I hope the chances to get sponsored wouldn't get affected if the codebase is public?
I'm so very thrilled to see such support from you people ^_^ This is so awesome <3
Can I get any updates on what is being decided or going on regarding the continuation of MathMash, if it is possible to be shared?
I cannot signup for an account. Am I the only one encountering this problem ?