Hello Codeforcers!

Another Amazing CodeTON Let's Go !

As a tester I really enjoyed the round and I highly recommend everyone to participate in it!

As a tester, this round will happen at a really funny time!

As a tester I really liked the problems, I recommend you to participate!

What can 1 TON buy me ?

Doge council decided that problems are great and you should participate

As a tester, I'm sad I couldn't participate.

OMG! rainboy is tester!

As a tester, I can say that this round is GOATed!

As a monkey tester, the cows are friendly :)

As a tester, smax orz

as a tester with photo of Stewie Griffin i say .........................................................................Brian Griffin

smax orz

As a tester, I enjoyed helping Farmer John with his never-ending problems.

As a tester, I can confirm the epicness of this contest.

As a tester, I have to say, excellent round, I hope everyone enjoys it thoroughly.

Having such intelligent individuals commenting on the problems is very encouraging, yet depressing at the same time.

Have a nice contest!

orz myvaluska the pupil tester

As a non-tester, I want to say that I hope the round will be cool

Best div ever

Is the score distribution right (1250-750) or it should be (1250-1750).

1800 plz!

Heh, just realized it would be ~4.5 years since my last rated contest, and I'm now kinda willing to take part in a rated one for old time's sake.

Hope that I would not get a -ve delta T.T

UPD: I screwed myself up badly T.T Still the problems were great anyway!

I wish codeforces had the same high quality UI design like ton.org does.

Good luck to everyone!

First time participating in a CodeTON, what is the difficulty of the problems in USACO terms?

Thank you in advance)

Problems of CodeTON round has always been very unique and enjoyable.

Hope for a enjoyable round.

Excited for this one, let's goo

value of TON tripled since the last CodeTON round, it's $5/TON now

so the first place winner will receive a prize of $5,000. wow

I'm so excited for this contest

Looks like Codeforces has some serious issues with Leetcode.

I believe that listening to the best video game official soundtrack may help your performance during this round.

i want to work at TON. plz give me job. I know Tag language, a little. I identify myself as a lgm as well

Thank you all for this wonderful round. I am very excited!

I'm glad that the prize isn't NOT coin :D

mike was too lazy fixing the problem ratings so he thought why not remove rainboy completely from the contest

WOW! Benq Geothermal and rainboy! This test will be wonderful!

What does (1250+750) represents in terms of points, like do we need to solve both the problems to get the points, if not why the D problem is of 750 pints ?

Another 1024 TON to tourist.

Can newbies or beginners register??? And solve problem will there degradation in rating if my problem goes wrong???

i hope i can get 2 ton!

good luck everyone :>

As a tester, I almost forgot to make "as a tester" comment.

Anyway, the problems are great! Huge orz to the setters and I recommend everyone to participate in this round.

left after seeing polygons...

very tough contest ;(

INTERESTING_FORCES unfortunately got so many penalties in C2

Very good and interesting problemset.

this contes could be better

Problem D: Learning to Paint is a straight-forward application of the famous interview problem.

I have added hints and thought process for this problem on CF Step.

254174144

Problem D. Can someone explain, why random gives TL?

#include <bits/stdc++.h>
 
using namespace std;
 
const int N=1010;
int a[N][N];
multiset <int> dp[N];
int perm[N];
 
void solve(){
    int n,k;
    cin>>n>>k;
    for(int i=1;i<=n;i++){
        for(int j=i;j<=n;j++){
            cin>>a[i][j];
        }
    }
    for(int i=0;i<=n;i++) dp[i].clear();
 
    for(int i=1;i<=n;i++){
        dp[i]=dp[i-1];
        dp[i].insert(-a[1][i]);
        dp[i].insert(-a[2][i]);
        while(dp[i].size()>k) dp[i].erase(--dp[i].end());
 
        if(i<3) continue;
 
        for(int j=0;j<=i-3;j++) perm[j]=j+3;
        random_shuffle(perm,perm+i-3);
        for(int l=0;l<=i-3;l++){
            int j=perm[l];
            for(int x : dp[j-2]){
                if(dp[i].size()==k && x-a[j][i]>=*(--dp[i].end())) break;
                dp[i].insert(x-a[j][i]);
                if(dp[i].size()>k) dp[i].erase(--dp[i].end());                
            }
        }
    }
    for(int i : dp[n]) cout<<-i<<' ';
    cout<<endl;
}
 
int main(){
    ios_base::sync_with_stdio(0);
    cin.tie();
 
    int tt;
    cin>>tt;
    while(tt--){
        solve();
    }
 
    return 0;
}

Ohhh noooo T_T tourist.

the problem f is broken

Can anyone please explain solution to probelm-C2

is C2 constructive, casework problem?

calculate the distance, first select power of 2 to get extra, second select even until 2, then add rest? idk

need hints for c1 :/

A question about task E: "It may be the case that the game will continue indefinitely" as far as I'm concerned, that's not true, right? I couldn't find any example configuration where the game continued indefinitely

As a music gamer, I got defeated by the tiebreaker (looking forward to the solution). Anyway thanks for the cool round!

why did I notice E so late? T_T, idk how to solve D without segtree or efficiently with segtree

Can anyone tell why my code is giving wrong answer for question c2? https://codeforces.net/contest/1942/submission/254186598

UPD: Nvm, system tests are over

Problem C has definitely ruined all this competition.

i did bad, very bad. c1 defeated me. i don't know why i did not notice that the inner polygon is also created for 2 hours.

well that was a waste of a morning, lol

In D problem1
1- if i do dp to get maximum sum(mx_sum) and hm ways i can get this sum (freq)
2- k-=freq
3- then dose 1 again but i wanna second max so i use the mx_sum from last dp.

is this solution will pass?

A frustrating contest indeed !!

Are some of my observations for E incorrect?

• The only thing which actually matters is the min gap between some $$$a_i$$$ and $$$b_i$$$, i.e, $$$min(b_i - a_i)$$$.

• Any move always preserves the parity of this, meaning P1 will always win for an odd value and lose for an even value.

• The gap between $$$b_{i - 1}$$$ and $$$a_i$$$ doesn't matter since A's movement left / B's movement right is bounded while the other's is unbounded (subject to the loss by parity above).

• So for each odd gap upto $$$L$$$, we can count the number of ways of the min gap between an $$$a_i$$$ and $$$b_i$$$ being exactly that, the answer should be the sum of those values.

• We can get the ways of assigning gaps so min gap between $$$a_i$$$ and $$$b_i$$$ is $$$\geq x$$$ and rest are $$$\geq 0$$$ using bars and stars, so we take (ways of $$$min\ gap \geq x$$$) — (ways of $$$min\ gap \geq x + 1$$$).

This doesn't work for the large sample, any guesses on what I might be missing? (or is it just an implementation skill issue?)

Any reason for such tight constraints in D, isn't brute force O(n^2klogk)

Not gonna give any div1+div2 round onwards. Only div2 seems to be the way.

Great contest. Loved the problems! 💯
Fixed my bug on problem D only to see the "contest over" message flash right before I could submit. 🤧
Well, that's also a fun experience once in a while. The mistakes stick harder! 😂
Expert, here I come! 🤓

not able to solve prob D since last 3 rounds. Disappointment as always

Can anyone help me with this? Why is this wrong? https://codeforces.net/contest/1942/submission/254188720

Could you please pose H in a data structure training contest... (or at least have a subtask?) From $$$O(NQ)$$$ to $$$\widetilde{O}(N+Q)$$$ is apparent (if you have prepared) and boring.

.

Is there any $$$O(nk)$$$ solution for D?

E

I misread it as selecting the kth cow and moving it (which is also a common situation, I think), and wasted an infinite amount of time. It would have been better if you had written it like a subset.

Can someone please explain how my $$$O(n^2log(k)log(nA))$$$ solution passes in D?

Submission

Thanks for the contest, I liked ABCEF, all are high-quality interesting problems. But I dont understand why problems like D still being accepted for Div1s in 2024, isn't it just very standard problem?

just realize number of participant too low compare to regular round, why is this the case?

Little bit sad for my unclear submissions for C, basically it's an easy observe problem with short code...

Thanks for the contest!

For problem E, the case of $$$n = 1$$$ previously appeared in AGC 020 A which I wrote — not a big deal of course, but it helped me to come up with the solution a little bit faster.

Hello folks,

Do you know that JavaScript V8 4.8.0 was released in 2015? And included in node since 2016. That's over 8 years ago. Unlike most programming languages, JavaScript has evolved significantly since then. Latest available V8 version is 12.5.0 (Mar 18, 2024).

I'm well aware that JS is not usually used for competitive programming. But using obsolete language version is a guarantee that it will stay this way.

Cool round, had fun. Congrats to the setters

Read E for the first time and solved it in 20 mins, bruhhhhhhhhh

Cool round , although it was strange to have a C like this

Anyway , does anybody has 7 rating points to donate to me :(

It seems that G is a little too easy for the position? I personally consider F more difficult than G.

Why has TON skyrocketed so dramatically?

Can anyone help me with Golang

https://codeforces.net/contest/1942/submission/254314439

For this problem, in test 6 with n=200000, TIME_LIMIT_EXCEEDED even if I only debug and read & print the input

MathForces

I think there are too many math-like problems.

How to exchange TON into dollars?thanks!

Hi guys, I am new to codeforces so I want to ask something from you guys. I am very polite about this. In this CodeTON contest I solved Accepted 2 Questions and two were Runtime error. But My Rating Change is 0. Not even Positive or negative. Can you tell me why this hapenned? I also got a positive score of 1512 but my rating change is 0. Please help me figure about that.

Ummm, So how can I recieve the TON? I only realised that I can put a wallet in setting after the contest :))

i got a message from system saying that my solution coincides with some other solution for C2 1942C2 - Торт на день рождения Бесси (сложная версия) i think this is a coincidence an exactly similar question with the same logic was asked in one of the regional math olympiad i gave in fact for this particular question i gave three wrong submission before it was finally accepted and those submissions also used the same logic you can check that. System testing has skipped my submission can someone please help MikeMirzayanov priyanshu.p. Around 60 other people have a similar solution so it can be a common solution.

Dear Codeforces and MikeMirzayanov,

My Python submission for problem 1942C2 was independently developed, and any similarities with other submissions are coincidental. The logic employed in my solution was based on my unique approach, building upon the solution I devised for problem 1942C1. I assure you that there was no intentional violation of the rules.

Help Please