Heyo Codefoworcers!
vgoofficial and I are very delighted to invite you to participate in Codeforces Round 971 (Div. 4), which will start on Sep/03/2024 17:35 (Moscow time). There will be $$$7$$$ problems, with one split into three subtasks, to be solved in $$$2$$$ hours and $$$30$$$ minutes. We encourage you to participate and hope you have fun, regardless of your division!
The format of the event will be identical to Div. 3 rounds:
- 5-8 tasks;
- ICPC rules with a penalty of 10 minutes for an incorrect submission;
- 12-hour phase of open hacks after the end of the round (hacks do not give additional points)
- after the end of the open hacking phase, all solutions will be tested on the updated set of tests, and the ratings recalculated
- by default, only "trusted" participants are shown in the results table (but the rating will be recalculated for all with initial ratings less than 1400 or you are an unrated participant/newcomer).
We urge participants whose rating is 1400+ not to register new accounts for the purpose of narcissism but to take part unofficially. Please do not spoil the contest for the official participants.
Only trusted participants of the fourth division will be included in the official standings table. This is a forced measure for combating unsporting behavior. To qualify as a trusted participant of the fourth division, you must:
- take part in at least five rated rounds (and solve at least one problem in each of them),
- do not have a point of 1400 or higher in the rating.
Regardless of whether you are a trusted participant of the fourth division or not, if your rating is less than 1400 (or you are a newcomer/unrated), you may choose to participate rated or unrated.
We want to express overwhelming gratitude to the following orzosities for making the contest possible:
Vladosiya for his awesome coordination and mesanu for reviewing the problemset once again.
Our MVTs (Most Valuable Testuwuers), satyam343 and Dominater069, for their dedicated contributions.
The rest of our army of testuwuers: omeganot, nskybytskyi, awesomeguy856, 18o3, Lilypad, chromate00, Sacharlemagne, ntarsis30, Prady, Non-origination, yash_9a3b, ETL, Orange905, MatthewC3297, mathtsai, macaquedev, jcai972, and cj8450.
MikeMirzayanov for all that jazz.
01100 00000 11000 10011 00111 01000 10010 01001 01110 10100 10001 01101 00100 11000 01011 00100 00000 00011 10100 10010 10010 10011 00000 10001 10110 00000 10001 00011
UPD: The round will be unrated, even though m1.codeforces.com, m2.codeforces.com, and m3.codeforces.com were functioning correctly. While there were issues on the main site (which lasted more than an hour), no participant was able to view the leaderboard, ask a question, or receive an answer.
As a testuwuer I can confirm this contest has W rizz and you will get ratioed.
bruh
omg! cry contest again! (cry fan)
you depressed or sth? stop crying =D
XD
As a tester,
As a testuwuer, I can read Morse at 10 words per minute.
c.c. is best as expected
English version:
THIS CONTEST IS A DIV4 INDEED
THIS CONTEST IS A DIV4 INDEED
As a participant
.. ....... .... — .--. . ....... .. ....... .-- — -. .----. — ....... --. . — ....... -. . --. .- — .. ...- . ....... -.. . .-.. — .- ....... ---... -.--.-
i wanna be a testuwuer one day uwu
same
As a testuwuer, I must say the problems are uWu
as a tester, Dominater orz
Noice! cry round!
Red0 orz
Xbalanque orz
Sidenote: I'll be off contests for a few months to just focus on improving skill. Hopefully I'll reach CM the next time I do contest!
I will root for your comeback Red0 orz
I will pray for your success in future contests heavenly_principles orz
How do you go about doing that? What do you mean by improve skill
when will u be a Red red0
As a participant, I want to solve max questions
Just like my alter ego, Anita Max Wynn
As a tester, I like chipotle.
cry is the best! cry cry cry :)
Div-4 is my only hope for AK :) Good luck to all!
I hope to get AK too. Good luck to you.
what does AK stand for ?
i think it means solving all problmes of that division.
All kill which means loving every problem
As a newbie, I want to learn how to study CP. Plz let me know how I can contact with you in other communication channel like skype or discord.
best thing in month
maythisjourneyleadsusstardownard
what does this even mean
how did you decode it ?
map the strings to decimals and decimals to alphabets (0-25)
Decoded message for the binary pattern at the end.
May this journey lead us starward
I wish you all good luck for div 4.
Three subtasks is crazy !
As a tester I confirm all problems are interesting
As a tester, I confirm the problems are as good as cry
go learn unicode
I hope to reach Expert after this round!
Can u give Div4 contest as a rated participant being a Specialist?
no
hey as you can see my rank i am newbie and as a newbie i am going to as a newbie question " will it be rated for me" will i get score?
Yes, It will be rated for all participants with rating less than 1400. i.e. it will be rated for all newbies and pupils.
Oook thankyou
this aged like milk, xD
was not expecting that, XDD
One genuine question to cry, from where do you get such good emojis ?
gsrixiw mw hmz4 mrhihi OWO
May this journey lead us starward.
what do u mean, lol?
As a testuwuer, I must say the problems are uWu
May this journey lead us starward!
Yay! Div 4 Round
What is this message at end?
MAYTHISJOURNEYLEADUSSTARWARD
"01100 00000 11000 10011 00111 01000 10010 01001 01110 10100 10001 01101 00100 11000 01011 00100 00000 00011 10100 10010 10010 10011 00000 10001 10110 00000 10001 00011".split(' ').map(bin => parseInt(bin, 2)).map(x => String.fromCharCode(x + 65)).join('');
Hope to get 1300+ rating
best thing for me after dropping 216 rating in 4 contests and went back to pupil
am i the only one who did this?
maythisjourneyleadusstarward
@cry fan here :) hoping to do well and excited for it!!!
me too
One task in three subtasks? omg, I had never seen that before! I hope the contest would be amazing, gl&hf
dcode.fr my beloved
May as well join in on the brainrot fun!
As a uwuriter, I hope you do well and UwU the OwO out of this round :)
Good emoji.
The binary code at end : May this journey lead us starward.
Another cry contest? Do we remember this Div 2 C with bad score distribution? https://mirror.codeforces.com/contest/1998 Or this Div 3 D "counting is fun"? https://mirror.codeforces.com/contest/1996
For Div 4 guys out there, be careful. Assume it's speedforces, cry doesn't like creating solvable for your level problems.
The Div 3 problem just used some well known math, I think it was very doable. As a tester though, I'm curious how you'll react to this contest.
Please don't do cheating everyone. This discourage us.
hmm, that's interesting
I am a skibbidi testewer
like to get luck!
I am so excited about this div 4 Contest But, how come the Div 3 Round from yesterday not make me newbie I am still unrated And I solved a problem in it too
just wait for the system testing to finish, it should be over soon
It's been a long time And I didn't get a rating from that
may this journey lead us starward
"May this journey lead us starward." The binary code at last.
MAY THIS JOURNEY LEAD US STARWARD
Cry Always make me Cry :(
Good luck everyone uwu
I remember last time there way a monkey and you have made us cry on problem C, what is your plans now [fearful emoji]?
is my cutie cutie cowontests ready yewet?
where is sum ??
I ate him
vgoofficial orz sum orz
vgoofficial damn man that Display Picture hits hard :)
cry oworz
About 5 years ago ratings used to start from 1500. In my first contest I solved one problem and my rating got reduced to 1430 something. "do not have a point of 1400 or higher in the rating", I have not been able to touch 1400 since then, am I not considered a trusted participant?
u are a trusted participant .. ur current rating needs to be <1400
Please make it easy i wanna be a specialist
I hope to get at least 5
Hopefully no gpt solves
If I became a specialist in last round and registered before will I be rated or not for this contest ........Cause when I checked the participant list I was not marked as unrated as *user_name is the sign for unrated participant
been waiting for div 4. i am new here i try div 2 solved one question and after that no a single question i am able to make. Hope this one goes well.
The Binary Code
may this journey lead us star wardAs a non-rated contestant, this is my first unrated round.
me too! Because I used the feature haha. No more farming on these comments
Surprise! It's become an unrated round for rated contestants too
Cry is a rizzmaxxer this conetst got W rizz but me no attend so L Rizz (erm what the sigma).
oh skibidi round)
first time to unrate, wish to solve 6 problem
aiming for 0 solved
uwu
hope to become specialist in this contest
First unrated contest (^^)
Got busted in the last Div3 and now again rated for DIV4, expecting to reach cyan again.
As a participant, orz BonTapHoa , nguyenkhangninh99 , lalid , huanjua , chikien2009 , Soab , Jackduy
orz
hope to become pupil in this contest, good luck everyone
Can someone help mere here in these question of recursion i am getting error "Time limit exceeded on test 2" my code " ~~~~~
~~~~~ " I am not understanding why its happening. PLease help i tried ChatGPT already but his solutions are not satisfying or capping the input
where is your bro "Sum" as cry and sum :) ?
How to participate in the contest?
just participate :))
Yes, i solved. Thanks
I think it will be a great round!
01100 00000 11000 10011 00111 01000 10010 01001 01110 10100 10001 01101 00100 11000 01011 00100 00000 00011 10100 10010 10010 10011 00000 10001 10110 00000 10001 00011
If we map 00000 with 'a' and 00001 with 'b' and so on
It translates to : may this journey lead us starward
Only div 4 can save my ratings now ; learning and givng contests is surely good but it costs rating too without practising
I'll ak in 20 minutes.
yeah lets c who solves more this round , good luck
come on! :)
contest is unrated :(
Hoping to solve 5 questions in this round!
All the best Prateek077
they made it unrated. dont know if they will do a div 4 again in few days .lets hope so
I Got 5, but unrated D:
Don't be upset bro. This contest just not for you.[problem:E= 111,122,133,000]
"MAY THIS JOURNEY LEAD US STARWARD"
Had to use chatgpt, lmao.
do not unrate plsssssss
lol
your request was declined by the mods .
Div 4 contest after a month and it became unrated
give more time and do it rated pls
yes pls
ok
went unrated (insert crying emoji)
So wonderful round! I was top 2000, but it became unrated :(
Solved a problem in 1.5 mins for the first time in my damn life, and they made it unrated :(
same ; i solved problem A for the first time this faster ; bad day :(
Div.4 always suffer from poor performance? not the first time to occur that! so why to be unratted? An unsuccessful decision
i agree that cf is always slow.. but today's condition was incomparable to any of the past contests..it was the worst today.. so it was correct to make it unrated ..
What, unrated, well, (∩︵∩) bye, gonna search my waifu!
POV:
Codeforces is temporarily unavailable
WHAT THE HECK IT IS UNRATED
Does not count ratings
Solved half the contest on m1.codeforces.com and gotta say, the minimalistic experience was quite refreshing :D
same ; first i though they blocked coz it showed that the admin has blocked the site and all.
I hate PROBLEM C!
Such good round but got unrated! I was prepared to do my best and reach Specialist. But codeforces became queueforces and then website crashed.
it was supposed to be my combeck round ;( as i was about to solve F it become unrated even though if it didnt crash i would have done much better
Is this unrated?
it is clearly said that it is unrated
Div 4 could be one of the only chances for noobs like me to get ratings improved.However,unrated.:( ......Hope for the next turn.
Codeforces server is Mike's phone.
Really wish it wasn't made unrated. Last div 3 contest went terrible, and I was hoping to give a comeback with this one. Bad luck :(
managed to solve 6 problems within 1.5 hrs for the first time!
in the end..
it doesn't even matter , linkin park
was having the best performance of my career and then i heard "unrated" :(
Bro solved 5 problems just for the round to go unrated ToT.
very sad that the contest got unrated. Very fun questions
I could have gone back to specialist again if the contest was rated. This is just sad.
It happens, life is so fair
it was a cute round , i hope it was rated
I'm surprised I solved D under pressure. I'm usually bad at geometry
same
please rate this round 😭
I didn't find anything unusual, div3/4 has been always slow and lagging due to large number of participant.
why unrated this?
today's condition was just worst.. thats's why
For me, I was unable to access Codeforces for almost an hour, so I had to participate in the contest on m2.codeforces.com. I believe the downtime was long enough to warrant making the contest unrated. Of course, there were also queue delays in previous Div. 4 contests, but they were limited to the beginning of the contest and were usually resolved within 15 minutes.
Apart from that, I feel sorry to hear the bad news, especially since the problemsetters must have worked hard to prepare for the contest.
But you're not even an official participant. Honestly people taking part in the contest unrated should have less priority in the queue of submissions. You're not even doing it rated and it screws people that are actually doing it rated
Making the round unrated just for the sake of "speedforces" just doesn't make sense to me tbh. What matters more is someone who solves more problems will place higher than someone who doesn't. Also the situation is the same for everybody, so it doesn't affect much to whoever has the ability to solve more problems.
i dont think so...i think many of the participants could not even see the questions after 2 to 3 mins of the contest ... and it is not due to internet issue but the server was down so it was fair to make it unrated imo .. if it was after 2 or 1 and half hours then mayb making it unrated would have been unfair.. but the problem was from the very beginning
who can tell me how to do E?
binary search the answer over the range (k,k+n-1)
ternary search
You can also reduce the equation to a quadratic formula (ignoring the absolute values)
The minimum value must be near the vertex or the roots of the equation.
Binary search
in G1, isn't the idea just find the longest consecutive subarray in the interval $$$ [l, r] $$$ and then answer for that query will be $$$ k - x $$$ where $$$ x $$$ is the length of longest increasing consecutive subarray. I was solving that with segment tree and some dp precalculation. Even my stress test couldn't find anything wrong.
Submission link
Here is a counter example:
let $$$A = [1, 0, 3, 0]$$$. Clearly, the longest consecutive subarray here is 1, so your solution would produce $$$4 - 1 = 3$$$.
However, let $$$A_2 := 2$$$ and $$$A_4 := 4$$$, then we can create a consecutive subarray with only 2 moves.
consider this example:
[1, 2, 10, 11, 12, 6, 7]
the answer for this array is 3, because using 3 operations, I can change the array into the following:
[1, 2, 3, 4, 5, 6, 7]
Whereas based on your reasoning the answer is 4.
Contestants who solved problems: "i won but at what cost?"
Stressforces, I found that my C code was wrong 30 minutes after submitted.
Anyone who solved E in O(1)?
yes
pow will take logn
no
I am greatly humbled by this round. I usually try solving at least more than 4 questions in Div3, and 3 in div2. First time getting stuck at Div4 barely at 2nd question. I guess I need to stop practising 1400s and go back to 900s and 1000s.
Today's C was very Sketchy not like usual Div4 C, so dont worry
I didn't gacha Yunli so I can't solve G. So reasonable.
yunli will come home
I cannot submit code to practice after contest ends?? Just gave up after it became unrated, want to practice now.
Cf really need to ramp up their scalability
Edit: Problems were really good. I enjoyed solving G1 and G2 a lot (though solved G2 just 5 mins after contest ended )
Or Thanos should snap his fingers one (or even two) times to drastically decrease the number of participants :)
Regardless of this contest being unrated, it was an insightful contest with an interesting set of problems!
I enjoyed the problems very much!!! thank you problem setters.
"MAY THIS JOURNEY LEAD US TO A REWARD" cry,cry,cry
Ok who is it that plays osu!mania?
Please don't host div4 anymore if it can't handle such a large amount of participants :(
(the problem set was nice though)
People down-voting clearly don't get it. Guess what, just after I received the notification saying the contest is being made unrated, the platform became completely accessible to me. Before that I couldn't even open a problem on the mirror sites. The amount of traffic the platform faces during a Div 4 Contest is pretty huge. Let's make it clear — several people in the organizing team are putting their efforts to bring a good Div 4 contest. If all of that goes to trash due to queue issues, it's better to host them only if the site can handle high traffic.
Cryforces
WaitForces
System testing is taking too much time :(
satyam343 loves math.
i think you could still make it rated considering the fact that even if the main site worked poorly,m1 m2 and m3 were fine so you could still get around it. SO PLEASE GIVE RATINGS thanks:P
no they weren't working well also the whole site wasn't working
When will I be able to virtually participant in this contest? The contest ended almost 2 hours ago, and the system testing is also showing 100%. How much do I need to wait for that?
when can I submit in practice , it is still showing system testing 100%
just after the contest got unrated suddenly every one is getting the best performance in his whole live and would have got grandmaster if it was rated :)
lol true
Can someone please hack my Problem E solution?
why tho
why is there a hacking phase if its unrated? I´m not judging Im just curious
Can someone help me find what was wrong with my problem C solution? I just couldn’t find what I did wrong even after looking at the editorial. Submission #279601674
I think the problem is that you are performing integer division you should make k a double or multiply by 1.0 or what ever to make the division correct
Fails on input x = 1, y = 0, k = 10
Use (a + b — 1) / b for ceil(a/b)
Really ?? That’s not first time, every contest div4 the site can’t be loaded and shutdown Cryforces
what would be the 862 test case of c number problem..??
all test cases of the form x>y(strictly) k=x.
I think this contest should be unrated for people who where to get negative score,and the rest get their deserved points but in a lower rate
I feel there is no herm in putting 1 or 2 hard problems as the final tasks in every round. Which’s beneficial for both unrated as well as rated participants. Unrated participants would have something to think of rest of the contest and rated would have something to upsolve :)
Guessed difficulty
A — 800
B — 800
C — 800
D — 1000
E — 1100
F — 1400
G1 — 1800
G2 — 2100*
G3 — 2700**
*I did not seriously look at G3 at all.
**I did not solve G2, but I understand the solution based on the editorial, and kind of figured it out, nut I suck at segtrees.
You think 'E' is only 1100?
yes, maybe 1200.
It is simply just binary search, and triangle formula.
ig at least E is between 1000 and 1400
I would have gotten +70 delta if this contest was rated...
Nope, the announcement was made and I choose to stop solving since that point (I think there's many people choose the same). But tbh ur speed in this contest is good so it's kinda unlucky.
Yep that's true for me.. i stopped after the announcement was made (somehow was able to submit D after the server was stable for a moment then i stopped)...i was not able to see the questions even.. and after 2 mins of the contest it was a chaos for me..ofc most of us would have performed much better if the server was not down ..tho i will still get plus delta as many people didnt submit due to this lag but making it unrated was fair enough... don't know when will i get the next div4 contest again for a positive delta :)
I didn't even see the announcement (
i use m2
unrated?
i think you could still make it rated considering the fact that even if the main site worked poorly,m1 m2 and m3 were fine so you could still get around it. SO PLEASE GIVE RATINGS thanks
Nah, the moment it is announced unrated, there is no turning back, because at that point some people would stop caring about competing and not participate at their full capacity anymore, or even quitting the contest
Agree. When it is announced unrated,I just give up keep writing code and just go to sleep lmao.
My conest was severely laggy the entire time, with even the m1 m2 m3 code forces sites not loading. However, I still was able to solve ABCDE, under some of the worst conditions. Please make this contest rated
me too
I hope this contest would be rated too.
me too
I learnt a lot during this contest even though I cried due to speed.
I will do my best on your next contest.
Thanks cry
i have a very curies question does DIV 1 rated for tourist
Like come on we suppose to be learning problem solving, which includes knowing what to do when server is down but there are other fully functional sites, ugh i guess there is no other choice :*)
I hope this contest would be rated
I solved G1 with segment tree and sliding window
279788103
nice solution
May This Journey Lead Us Starward.
Is it allowed to use internet resources during contest like chatGPT? If so what if many people use the same sources during the contest does this come under plagarism?
The one time I was able to give a good contest and it became unrated :')
I become atleast (master) if random madafka chinese didn't ate bat in 2019
Downvote comments does not change reality
G2
Solution using Suffix sums by Precomputing lesser values to the right [ONLINE]: 280036192
Solution using Mergesort Tree[ONLINE]: 280017871
Solution using Square Root Decomposition[OFFLINE]: 280049782
Test 1.
Fact: Old contest contest authors and coordinators aren't creative and good enough (not all of them 1 of 10 could be good) all of problems look same an array and some operations, and some other same problems problem A, B and C in most of contests are greedy, constructive algorithms and sometimes number theory
I have many accounts and I compete in many contests and looks since many years contests quality are getting worse why anyone never talks about it?
yay
English
pickme
Who made problem F