Meta Hacker Cup Round 1
Good morning! Meta Hacker Cup Round 1 starts on Saturday, October 7th at 10:00 AM Pacific in under 48 hours! Anyone can register for Round 1 this year, even if you haven't participated in the practice round.
Important info:
- To qualify for Round 2, you must solve at least one problem in this round. (Due to having too many submissions in the early part of the contest, we relaxed this requirement from the earlier one of needing to place in the top 5000 of the round)
- The contest will be 3 hours.
- As usual, you may not discuss solution ideas or code until after the contest hours is over. It's your responsibility to make sure that your code is not leaked. We'll DQ contestants if we have reason to believe they shared code or solutions with others.
Hacker Cup Round 2 Conflict with ICPC Regionals and WPC
Round 2 will overlap with some ICPC regionals and the World Puzzle Championship. For people able to prove that they will attend an official International Collegiate Programming Contest (ICPC) or World Puzzle Championship (WPC) during the day of the Round 2, it will be possible to get a bye from Round 2 and go directly to Round 3.
To get the bye you must attend one of the events during the day of Round 2 and finish in top 500 in Round 1. At most 50 contestants will get a bye; if more than 50 qualify, only the best 50 of them in Round 1 will qualify. To be considered for a bye, send an clarification request before Round 1 with the word "ICPC" or "WPC" followed by your name. We will later validate your status for the bye.
Prizes
T-shirts will be awarded to top participants based on performance in Rounds 2 and 3. Contestants who do not qualify for Round 2 cannot earn a prize. More prize details will be announced after Round 1.
We’ve put a lot of work into these problems, and we hope you enjoy the contest. Good luck, and see you on the scoreboard!
is it rated?
we are div4, we don't ask for rated, rated ask for us
?detar ti si
It depends upon what's your rate
I mean rating..
I'll write "is it rated?" even when I'll become GrandMaster. It's just funny joke for me don't know why people downvote it.
Become GM and comment the same thing, you will get the reverse thing xD
GM is hard to be I'll stick to my goal Master
Earlier Round 1 was used to be 24 hrs long, any specific reason you changed it to 3 hrs?
https://mirror.codeforces.com/blog/entry/119880?#comment-1063462
Thanks for linking it. Personally, I did never felt it like mandatory homework, it was quite fun.
fun of a 24 hr contest will always be <<<<<<<<<<< 3 hr contest
Will the byes affect the number of R3 slots that can be earned by competing in R2? For example, let's say fifty people receive byes: will only the top 450 (rather than top 500) advance from R2 to R3?
I'm guessing the answer is no and that the top 500 in R2 will qualify for R3 as in previous years (and thus slightly more than 500 people will compete in R3), but I wanted to confirm in advance since this doesn't seem obvious from the blog post.
They will not. Up to 550 people might be part of round 3.
"Contestants who do not qualify for Round 2 cannot earn a prize", just to clarify, who applies for the bye and goes straight to Round 3 is still eligible for Prizes right? Also, what about if someone applies for the bye and ranks between [501,5000]? I assume they do not advance to round 2 either, right?
For ICPC Taoyuan regional, I also want to note that the time for MHC in UTC+8 is midnight 25:00.
Therefore, it's still possible for people attending Taoyuan Regional to participate in MHC R2 if they give up (some of) their sleeping right before the real ICPC.
Upd: According to this, there wouldn't be a second chance, so you should think twice before requesting a bye.
Can I check will the top X participants of round 2 already be given t-shirts? Or are the t-shirt winners only decided after round 3? Could you specify the value of X upfront? The contests are all 1-4am in East Asia timezones and I want to estimate my chances and whether it is worth doing 2 or 3 contests at 1-4am in the middle of so many precious weekends as a working adult... Thank you!
You’ll know whether or not you’re winning a shirt at the end of Round 2. If you qualified for Round 3, your performance in Round 3 will determine whether your shirt has a “Top 200” badge on it or not.
That's a terrible rule.
I feel that placing in the 500th place in a round where 5,000 people can pass does not guarantee the ability to place in the 500th place in a round where 500 people can pass.
Also, https://mirror.codeforces.com/blog/entry/121073?#comment-1074629 According to this comment, even if they fail bye, they can increase their chances by reducing their sleep time.
If the top 50 people who don't participate in ICPC regionals or WPC could also Bye, I think the fairness would improve a little bit and fun...
I think one should be careful to ask for bye. If you ask for bye and from my interpretation of the rule, you cannot qualify to round 2 (top 5000), you can only qualify to the bye straight to round 3 (top 500 at least). Also if there are 1k Tshirts to be given in round 2, you decrease the chance of getting it by asking for the bye. Plus if you dont really qualify for the bye (that is, you are not attending the events mentioned) you might get disqualified.
If you request and fail the bye, we won’t give a second chance in round 2. Additionally, if it’s a widespread occurrence, the bar for getting a bye will rise proportionally, and you may have to place much better than top 500 in round 1 because of the top 50 constraint.
How is that important? What would one gain from getting to participate officially in Round 3? If someone is not good enough to consistently get into top-500 surely they have no chance of qualifying for the finals. Nobody is unfairly taking anybody's place in Round 3, as top-500 from Round 2 are advancing anyway.
I want to thank the organisers for such a foresight! It does not affect me in any way, but I would be grateful to have this opportunity in a different situation.
what about pants?? :sob:
excited
On https://www.facebook.com/codingcompetitions/hacker-cup/2023/round-2, it still reads "Welcome to Round 2 of Meta Hacker Cup. You can only qualify for this round by earning enough points in Round 1." — which contradicts "To advance to Round 2, you must place amongst the top 5000 contestants in this round."
Thanks, I've updated it.
It didn't age well
Reminder: round starts in 5 hours, open to everyone with prizes, ask for a bye BEFORE THE ROUND STARTS if you are eligible
*not for Round 1, I think?
The trial day of the Polish icpc subregionals is on the same day as MHC round 2. The real contest is on Sunday. Does that count towards the bye? Are organizers included?
I am a MHC organizer but while I cannot guarantee this (will confirm later), I think what you mentioned should be eligible for the bye. Also coaches, contestants and judges/organizers are eligible for the bye.
It's the MHC round 3 that collides with the Polish icpc subregionals, not MHC round 2.
Oh, right. Nevermind then, my bad.
Does Polish Collegiate Programming Contest count towards bye?. It is listed on https://icpc.global/regionals/upcoming.
No. Round 2 happens on October 21st. That happens on November 3rd to 5th.
I read it wrong, my bad.
By when will the clarification submissions be judged?
They will most likely not be rejudged. I suggest you to resubmit (It is possible)
Just saw the message rip time penalty
Hi! I get "Error performing query." when trying to validate, any idea what might cause this?
Same
Me too
same here
same
Is anyone else having problems with final submissions?
Yep, having the same issue submitting B1.
Yup same
Me too (with problem A).
unrated please
No problems on final submission here, I can't even reach that stage, because I'm stuck at "error performing query" trying to submit the validation output lol
Validate solution is not working for me. It's saying error performing query. Anyone else?
Anybody else facing issues on submitting?
broken servers
I get error when downloading grading file
i cannot submit a
Are samples not loading for anyone else?
Yep
I got error performing query.
why??
server's struggling to show samples too...
Sample input & output just disappear. Previously, I can see them, but now I can't.
Same here
Same error performing query:(
I can't find sample input output
It just won't let me submit my sol for A and my timer ran out.
same
Same as you
Its showing error performing query while I am trying to validate A
Same with B1
Unable to download validation input data
Directly downloading the input for A gives corrupt input (it says 20 cases but there are only 19 in the file!). I download it again and finally the input is not corrupt. Then I can't submit! "An error occurred on our end", submission timer expired... Please help.
I guess now we know the real reason of 24h and 72h preliminary rounds...
Beautiful work facebook team, absolutely beautiful.
I am unable to have the input validation work (at least for B).
Getting "error performing query" after submitting validation output for B1
Same here.
pretty sad to start this eagerly waited round with such technical problems...
It shows that 12 validation test cases in problem A, but only 11 cases seen.
Also, could you remove the blank line between the test cases please? python will have an error when reading it.
Same here
I'm unable to submit validation output. Saw:
Just refresh the page. It helped in my case. But the validation input is incorrect. It states there are 12 testcases. But it was 10 and 5 (I downloaded it twice — two different inputs).
The samples are not showing up for me. Can somebody post the samples of the second problem.
3
7
1 17 3 13 7 23 12
5
5 4 3 2 1
4
10 100 1000 10000
Case #1: 18
Case #2: 2.5
Case #3: 5445
I have the same problem
Getting 'error performing query' on validating output of A
I don't know whether I should laugh or be sad that the the "click here" for "An annnouncement has been posted by the organizers." doesn't work lol.
It says the following. You can access it from the Home page (above scoreboard).
Contest Announcement We're experiencing so many submissions that some appear to be failing. If you get an error when trying to upload your source code and output, please make a clarification request instead that includes both your source code and output for the problem you're unable to submit to.
On downloading the validation input, it is showing error!!
I (maybe we?) cannot validate our solution so even I can't download the full test...
+1
Same with me also. Stucked at validation check.
+2
I hope submitting code in the clarification request is enough.
They are saying to raise clarification in case of issue in submitting the problems, but how to submit when even validation isn't working?
It's not working!
can anyone give me sample I/O of problem A please?
I believe that would violate the rules
how? sample I/O is public information during contest
It gives you much more time for computing then intended. Everybody would bruteforce half of the problems that way :/
How do I make a submission without validating my output on validation data? Help can't make a single submission!!!!!
After Clicking Validate it shows:["Error Performing Query"]
Unfortunately, result of Meta layoffs?
Validation test for problem A appears to be wrong? T is 12 but there are only 11 cases
I count 12
Exactly! There are those newline characters which spoil the input file!
Is it rated?
Looks like I'm repeatedly getting "Sorry, something went wrong. We're working on getting this fixed as soon as we can. Go Back" whenever I'm trying to
Validate Solution & SubmitAnybody else facing this issue?
The question probably would be anybody not facing this issue...
Guess layoff really hurts everyone. Anyone able to get anything correct? Please make it unrated!
Seem like the 24 hours round 1 of previous years was good for reducing load on the server.
That sounds a little weird to me. Meta is not running our solutions, only comparing outputs. How many submissions can there possibly be that the server can't handle them?
It's still handling lots of requests I suppose.
Multiple people downloading a personalized 2MB file is not trivial.
error performing queryyyyyy
what will happen then? Will it be rescheduled or what? I cant seem to be able to submit the solution
they better reschedule it
codeforces >>> meta hacker cup
But meta gives Tshirts
I cannot see the samples.
What the hell is going on? error performing query??
still rated?
how about making it 24 hours while it's not too late?
Yeah, probably it's a good idea!
And, keep a minimum passing score instead of top 5000, so that time doesn't matter anyways.
It's Not Happening!
is there any way you can submit? I am getting error performing query!
same :(
What the zuck happened?
would've better host in cf
Looks like round 1 really escalated in the wrong direction
The sample input for B1 does not have enough test cases.
I cannot download the validation input
I downloaded validation input but it does not have enough testcases either lmfao.
I did but it ended up being corrupted with empty lines as well
This is the full sample input I copied earlier.
Here are the full samples
Thanks, though I've already downloaded them. Also use
```
your input
```
to keep input within codeblocks.
Could you send the output too
wtf
I am asking for the sample data, not the validation one
Sorry, can't send, my output isn't the same, and can spoil the solution of the problem.
You can see the samples? Lucky duck.
the testcase is fine. it's just not loading properly now
I can't even see the sample input for any problem, before it was visible now I can't.
Can you all see Sample Input and output?
for me its I/O format then Sample explanation
Same problem for me, it shows after 3 — 4 refreshes though
Can anyone provide the contents of the input file which many of us couldn't download please?
OMG, I failed to DL B1's validation. Sorry to say, but I guess the only choice is aborting the round.
For problem B1 validation input is not in correct format (some testcases are missing and have been replaced by blank symbols!)
It'll be cool if this round now gets rescheduled to some later date.
Now I even can't see sample input and output of the problems.
What is going on?
I have been unable to get my validation output checked for 40 minutes now and have not been able to submit it at all. The same for problems B and C as well. I think it is only reasonable to invalidate this round and reschedule it later or have combined round 1+2
Problem D: Today is Gonna be a Great Day
Is Anyone Able to Validate A, B1, B2?
I stayed up to 1 am, please don't tell me I have to stay up to 1am on another extra weekend...
It's been 45 minutes and it's still not working so unfair 303 people have made submissions I can't even make a single submission because of validation errors!
SecondThread rn
I think we are all advancing to Round 2.
it's almost 3am here and i guess there's no risk in going to bed right now....
Sorry but imagine if they had to run our code on their server LOL.
--edit: They're back! Yay!!!
And we have Codeforces that gives judgements within seconds.
Yeah this is unfortunate, hopefully they can resolve the issue soon.
I hate this pop-up from now on ~
Mine downloaded validation input not even in correct format.
Lost the urge to see other problems as can not even validate one. The contest is totally ruined -_-
Update: round turned out to be pretty good. It started badly, but it was "saved" from total catastrophe (like unrated CF rounds with 1h queues)
Does anyone else see:
Something Went Wrong Error performing query.
?
Yes everyone
Literally EVERYONE.
Metaproblems are too difficult to solve
meta be like: we have metaverse, bla bla bla.......... BUT cannot have good server like google codejam. I am not even able to validate test cases. Shame on Meta
I am not able to download even input files for problem B1
Is this the first time that Meta experienced too many submissions in Round 1? We were not able to make submissions in the first hour at least.
Based on the issues here, I think this round should be cancelled with another round to be rescheduled in a later date, or if that's not possible, then all registered contestants should qualify to Round 2.
We all got a literally bye from the system
... It's almost 3AM in GMT+9. Please just tell me whether I can go to bed or not...
wtf is this contest. nothing is working. didn't expect this from facebook. maybe this is the reason why nobody uses facebook.
right now, why they don't give an announcement?
Validating input works for me now, but what good is that if we don't have complete input.
Can anyone please paste samples for A?
3 7 1 17 3 13 7 23 12 5 5 4 3 2 1 4 10 100 1000 10000
Case #1: 18 Case #2: 2.5 Case #3: 5445
Thank you.
(
)
I would love it if someone could explain how to prevent and quickly solve such problems.
It won't let me submit B1, the timer will run out again
I have solved B1 B2, but am too scared to submit until I hear something from SecondThread
I thought codeforces servers are bad until I participated in this contest, Thank you mike.
I am still getting Error performing query.
My timer started, but when I try to submit I get an error message :(
Submit a clarification with output and source code
Worked, I tried it, got WA, tried again and doesn't work again :)
Clearly frozen, standings aren't progressing...
same
I thought Metaverse is already the worst thing that Meta had ever made until I participate in this round.
Still getting error performing query on validation for A
Don't submit.
It finally let me get validation input, and it passed. Then, I tried against actual input and it says there is a server error. And so, I wasted an attempt.
also, please let everyone advanced to R2. Not fair because of tech difficulties imo.
Yes and to balance out frustations, please provide T-Shirts to all.
um what? round 2 will determine t-shirts
imo, when there are serious server errors, it is not the fault of the contestant and the round should be unrated/postponed/etc.
Did you read the announcement?
Right now tbh I feel like they should have hosted this on codeforces itself...
why i have only 8 cases in input?
working fine with VPN, I tried with Proton VPN (Netherlands).
It worked for a moment but then again stopped...
I downloaded the C1 validation input two times and got different inputs each time. Did anyone else face the same issue?
The same happened to me for problem B. One line of the input is always missing
Yep wasted half an hour getting wrong answer downloaded the input again and passed.Thanks for the comment.
yep, solved C, but wasted whole hour debugging A, turned out after contest got the wrong validation input.
I am getting the "presentation error" verdict, even though my output format is correct. -_-
+
again a devastating expreience this time ...!
now you edit your statement. you asking help here instead of reading the question properly
nvm, I'm just retarded I guess
The first number is the array size.
sad
lol
The real problem is the diversity hiring. This is what being woke gets you.
YUMMY
Are you processing the submissions made via clarifications during contest, or do you plan to do it after the contest ends?
The way I understand the last update (12.15PT), it seems that they won't because they did reset the timer and expect you to upload your solutions normally now
The announcement says they will not. Best to just submit again
Why is the contest ending at 10pm CEST again? It was extended by 30min and then now that extension is removed.
Edit: nvm, resolved.
Try refreshing the page, for me it looks good
Looks like the criteria for Round 2 is changed from getting top 5000 rank to scoring at least 10 points.
4 points now
A request to introduce any subsequent announcements, especially contest extension, in separate orange boxes instead of changing the text in the same box. It's difficult to notice that something changes after you read the box for the first time.
For the last hour of the contest, I couldn't view any problems :(. I still can't. I just get a message that says "This page isn't available."
You should have used a VPN.
I tried that as well as clearing cache / cookies, using a different browser, and restarting my laptop. Interestingly I can view problems if I use an alternate facebook account from the same browser, so it seems like an account-level problem. Maybe I refreshed too much and got flagged as a bot xD.
I also experienced the same problem. I can view problems if I do not log in. Maybe I refreshed too much too?
Did they put unordered_map hack cases in C? I know it's my fault for not using vector, but there shouldn't be that much of a constant factor with unordered_map.
in B1 I missed that they had to be positive numbers... Any idea how the problem would've been solved if they could be negative?
Pretty good round overall. Congrats to the contest organizers who managed to solve the technical problems in time and save the contest from total doom.
Problems were OK. D was very standard, in my opinion: I just took some old code for segtrees with lazy updates, modified the node structure and updating function and that was it.
How do you solve D without segment tree?
You could apply sqrt-decomposition: store max, min values in a block and also the state of the block (flipped or not flipped). Flip all blocks that are wholly in the segment, and manually unflip blocks that are partially in a segment.
Although it took my solution to run for over some two and a half minutes (maybe my implementation is not optimal, maybe it's the block size, my laptop or everything together).
What? I literally talked about solving D with segment trees (segtrees).
Though I guess you can do it with sqrt-decomposition, too.
well that is every segment tree problem
In B2, it suffices to memorize all partitions' products (if the product is
<= 1e9) in a map before answering the queries and just make a map lookup for complexity $$$O(45000 + Q)$$$.is the intended time complexity for E something like O(NlogN (N/B) + QB), B = 1000 or something? What I did was partition the queries by k, and do sqrt decomp for each k-bucket (after doing some processing like hashing suffixes, removing short elements etc)
It's possible to get rid of the log factor. For a fixed $$$k$$$, you can run Mo for the ranges while updating the number of active values under each subtree in $$$\mathcal O(1)$$$. You can additionally track the count of the frequencies themselves. Since the answer for a particular query doesn't exceed $$$\mathcal O(\sqrt n)$$$, you can answer each query in $$$\mathcal O(\sqrt n)$$$ by simply iterating over the frequencies.
I'd still like to know if this is intended though. Took me some time to be convinced that this will run in time.
i did something similar; it felt kind of cheesy, but i suppose that's part of the meta (having 6 min to run your solution vs. 1-5 seconds).
edit: i sped up my implementation to run in ~30 seconds on my laptop (as opposed to the entire 6 min. on a server), so i am much more confident this is intended now
I was thinking something like this: if you order them, you basically just need to find the number of LCPs between consecutive strings that are less than the given number; now for an SQRT solution, you can get that easily with Mo’s algo after precalculating LCPs between consecutive strings when ordering the whole array of strings, and using a RMQ to get LCPs for any two strings in O(1)…
For logarithmic idk lol
I have an idea for logarithmic: basically, after you get LCPs on the whole array, if you order the queries by the minimum LCP, what you get is basically sequences of accessible sets of indices which join with each other. What this does is reframes the question to the number of accessible sets in which the indices reside, so now you can keep a segment tree in which you keep track, for every one of those intervals, in how many sets they reside. To update this segment tree, you just replace, for every interval that contains a value x in its set, you will change it into y. To do this, you keep track of which one of the sets was smaller and turn it into the bigger one, for a small to large optimization. Now for the query, you need, for an interval l r, how many sets blah blah bla. To do this maybe we use small to large again to join the log sets into which it gets divided and it might work idk
I liked D very much, very happy with my sqrt-decomposition solution. Overall the problems were nice, if only there was no technical difficulties during the first hour
Also God bless whoever put a test case with 5 elfs in the samples of A
Can anyone tell why my solution to C1 doesn't work?
My approach was that for each query I will find which indices are flipped at the end of the whole query. For e.g if (lets's say 1 is flipped 2 times it gets nullified.) Then for all the indices which have a pending flip, I flipped all multiples of that index O(NlogN). Finally, for all values which are still s[i]=1, iterating the Boolean array from the beginning, I flip that to 0 and add 1 to my answer, also flipping the multiples of the index just flipped.
Here's my code:-
Looks like it should work, maybe it's some memory issue? You don't initialize
flip.It's globally declared boolean array initally all set to false/0.
Also, after each test case I am resetting the changed values to false.
Got accepted for me. Are you sure you were submitting for C1?
That's the last thing to expect, writing a correct solution and still getting WA. T_T
Can you share your solution? I want to verify my outputs for each test case.
I got AC.
The initial input file that I downloaded was apparently somehow manually changed by me for the last test case, and I was getting a WA bcoz of that.
Same happened to me lol! So I got WA on C1 and AC on C2 lol
You use
ios_base::sync_with_stdio(NULL);and then immediately afterwards use the stdio commandfreopen. This is not supported, and your code may break in specific situations depending on the C++ standard library implementation.Can you explain a bit more, what do you mean by "not supported"?
Could you please allow downloading input not only after validation is passed? (and uploading source!)
It's already really cool that input is password protected and timer starts only when you are ready!
But downloading big files takes reasonable time when internet speed is bad and I even was forced to redownload files as downloading was stuck in the middle:(
Main problem today for me was that I passed validation for D 5 minutes before contest end and then was downloading 35.4Mb archive for about 3 minutes. Fortunately it was downloaded in time and I managed to extract, run and submit in about 30 seconds
Also it will be more convenient to download all inputs in one archive!
After this competition, I would like to thank Codeforces for this wonderful platform, which even in the worst circumstances and with the queue delay, works better than what I have seen today
Apparently, I received a corrupted file with missing lines for B2 and got WA .
bro, i had the same problem but for B1 can you tell me what is the wrong ? I'm very angry. https://ideone.com/R5Hnw8
Hello, in last standing round 1, i got rank 4300, and i check round 2 "You are not registered for this contest.", can someone explain?
ok bro that's same idea for my code and in that input: 1 44 gave me : 29 2 2 11 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 and that output gave me wrong, howww??
In addition, you will now advance to round 2 if you score any points on this round.
Yeah, cool!
I was unable to submit anything for 1.5 hours. Submitting clarifications seemed to be nonsense in this situation (as we already know, they won't review them). So I decided to abandon this contest. It seems like I should have been waiting for 30 minutes more to resubmit. What a waste of time.
Are you sure about that? Last year there was a similar issue as today. That time I sent my code as a clairification, which they later tested and gave me AC for the problem.
I think there's only one way to interpret their announcement (at the top of any problem statement):
We won't be reviewing clarifications sent to us prior to 12pm PT, so please resubmit to any problems you've had issues with with the remaining time.
You had been explicitly instructed to submit a request for clarification if you encountered technical problems. But if you decided not to do this because it "seemed to be nonsense", then it's on you. Consider yourself lucky, because in a real emergency situation such behaviour and attitude may cost you your life.
I wouldn't say a word if they actually considered these clarifications.
Yes, in their last contest announcement, they said they will not be reviewing clarifications sent prior to 12 PM PT (i.e. any clarifications in the first two hours of the contest will be ignored):
Since many people probably quit the contest in the first two hours after not being able to submit for so long, I can understand the frustration.
Nice problemset. Thanks to the Authors & Testers
After that horrific experience, I would like to thank Mike and the founders of the CodeForces website for all their efforts to help us develop our skill in problem solving.
GCJ before got cancelled also had some problems like this and got delayed further and further. MHC already had delayed schedule compare to last years and now this, I got a bad feeling about this. If we're lucky MHC may has its 2023 sessions complete but the 2024 sessions will likely won't happen.
Okay, so, you've delayed most asians' sleep by at least 2 hours, and this disaster happened, and decide to delay the sleep by another 30 minutes because the server is broken?
Yeah I do not regret skipping MHC
Is there something that could happen for those who requested clarification before 12 : 15 pm ,SecondThread ?
Why is the scoreboard not loading for me? Anything I can do about it?
Any hints for problem B2? I was able to do B1 with simple recursion, and no memoization.
For B2, I've thought of calculating the prime factors of P using the sieve method. Could someone explain how to solve it?
A thing to notice is that no matter what you do the final array will always have prime factors in their standard form(for B1). For Example:
The Prime Factorization of 1872 is: 2 x 2 x 2 x 2 x 3 x 3 x 13Ignoring the minimizing constraint on B1 you can just output this array and 1's to make sum = 41.You can notice you can combine prime factors, by combining them you take their product and check whether the sum is still <= 41. In the above example:
1872 -> 2 * 4(2&2) * 26(13&2) * 9(3&3)So to minimize the size you can combine prime factors.Do you have an implementation of this?
Check mine out
For B2 I used a dp solution to store the minimum number of factors required to make a sum m for a number n
Video Solutions for problems A-D!
Thanks
This is my first time participating in the Meta Hacker Cup. I scored 21 points in round one which technically makes me eligible to participate in Round 2. However, I don't see a sign-up button. Is it just a "if you pass just come" type of situation?
They're probably still in the process of verifying submissions, checking for plagiarism, etc, and will send out confirmation of advancement soon. But you likely won't have to do any extra registration to participate in the next round.
Thanks! Can't wait for the next round!!
The input of A I downloaded seems to be different from that used by the judge in the end, resulting in wrong answer. More precisely, the input file I downloaded during the contest has an empty line after Case 8 and does not contain Case 20.
(My source code can be found by searching my id "Brian_Hsu" on the scoreboard.)
Thanks for reporting, we are aware of this issue
On round 2 page, it is still showing top 5000 participants?
Thanks, it should be updated now.
has registration of round 2 not opened yet?
Previous comment
My solution to A seemed to fail system test due to the system problem, but they didn't rejudge it before determining who is in the top 500 place, which is a requirement to pass the bye.
If after rejudging and my solution is correct, then my score will be 68 and my penalty will be 6:49:75, which will be at around the 130-th place.
By the way, I don't know if they determine the top 500 place by penalty or not. I think that it shouldn't depend on penalty due to the system problem.
Big +1 to the second part of your comment. Given that the penalty time for this contest is obviously not an accurate reflection of contestants' ability, all contestants who applied for the bye and scored at least as many points as the 500th ranked contestant or the 50th ranked bye applicant, whichever is higher, should receive the bye.
I agree with you, but this did not make a difference on who would have qualified for the bye, so all good
I verified that the source code you submitted during the contest is indeed correct. We will discuss and check wether we can grant you the bye.
When can I know whether I get the bye? Thanks.
How many T-shirt will be provided in Round 2 ? TOP-2000 will get t-shirt in Round-2 like previous year?
Well, I have solved one problem in Round 1 giving me 10 points yet it showing you are not registered for Round 2. Anyone knows why?
same issue , 21 points & <=5000 (had a bad contest though) but should be able to register I guess
Yep, you should have qualified for round 2.
We were checking all the submissions for plagiarism. If you qualified, you should now be registered for Round 2.
"What prizes can I win? We'll announce prizes soon, but you can expect familiar prizes such as T-shirts and Elite shirts, plus cash prizes for finalists."
"More prize details will be announced after Round 1."
Any new information about that? I need this to estimate whether I can win a shirt or whether I rather should go to a concert on that saturday. Priorities and so.
Edit: Update see here https://mirror.codeforces.com/blog/entry/121572
Here we go again. Hoping for a good round :)
In solidarity with the Palestinian people, and because Meta policies and practices to mute our voices ... I'm not going to participate in Round 2 and any future Meta sponsored competitions
If anyone doesn't know what I'm talking about. Please check out Twitter and see what happening in #Gaza and the West Bank.