Hello Codeforces

Of course there is 6 7 joke

As a tester, I would like to thank the Codeforces legal team for reasons I am not allowed to disclose :)

As a tester I tested my first round :)

as someone who AKed last contest in 5 minutes, I think it's too easy for me, and to prove it to the world, I'm gonna be solving problems using ML based approaches, expected time to AK: 15 minutes, and yet I need to email mike to update my rating from previous round, because there is a bug, because of which system update rating only for >=1 placed participant's, and I got 0th

how on earth did nife and chromate agree to write a div together

As a tester, I have been banned permanently from Codeforces by nifeshe 😿

I hope Proof_by_QED nifeshe chromate00 are all having a good day.

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

After a long time giving a contest, hope to get +ve delta! Best of luck, everyone!

Failed zero cycles? Does Codeforces know MCSR ball knowledge?

hoping i can stomp the problems instead of being goombah stomped myself

Problem B of 1250?

TOO HARD....

Why am I expert tho :(

Also, between 6 and 7 problems will not be interactive, so you are recommended to read the guide to interactive problems if you have not encountered them before.

WHAAAT?

It's good.

I think this contest is to very hard

Hope to return my Expert, please.....

is this the beginning of my pupil era??

I hope that I will solve at least 2 problems

Will everyone be in the same rating table? If so, why write div1+div2 if div1 is possible?

Hoping for a positive change in rating..

"UPD: the contest has been delayed by 10 minutes to allow everyone to register." But the registration was already open for quite some time ???

UPD: My bedtime has been delayed by 10 minutes.

Ready with coffee, contest delayed 10 min

Guys, why all the problems are on the same topic — arrays, subarrays and permutations? The only problem on a different topic is a problem E.

Question to the coordinator of this round — shouldn't the round be balanced and contain problems on different topics? It's very boring when all the problems are about good and bad subarrays and permutations.

Mathforces

A and D are good but B and C2 is more like Guessforces also sample test very weak both B and C.

Oh hell naww, I will drop back to newbie after this contest ;((. At least, I will become the newbie with the most contribution on codeforces! (lol)

By the way, I love how CF's admins reacted in this contest; in just 30 seconds after Pa8ITER345's AC on H, Pa8ITER345 got banned.

I'm cry on C2....

Cucked by $$$C2$$$

What's wrong with my solution to C1? I thought the last k elements' ordering doesn't matter, but the for first n-k, a[i] = b[i] (unless b[i] = -1). 368564987

The problems are cool <3 but why is E way harder than F 😭😭

D is a very good problem! but How can I solve C2?

gimme d3 or i'll retire

F Too simple.

G Just randomly guess some sufficient/necessary conditions.

AI shitted the contest. Bad round.

bro the brainrot in b...

~~~~~~~~~~~~~~~~~~ void solve(){ int n;cin>>n;

for(int x = n; x; --x){
    cin>>a[x];
    int k;cin>>k;
    int fate = 0;
    vi offers;
    offer[x] = {};
    int lcx = 1;
    for(int i=0;i<k;++i){

       int y;cin>>y;

       for(int oy: offer[y]){
         int v = __gcd(oy, a[x]);
         v /= __gcd(v,lcx);
         if(v==1) continue;
         lcx = gcd(lcx * v, a[x]);
         offer[x].PB(v);
       }

       fate += dp[y];

    }

    if(offer[x].empty()){
       dp[x] = fate + 1;
       offer[x] = {a[x]};
    }else dp[x] = fate;


    cout<<dp[x]<<endl<<flush;

}

} ~~~~~~~~~~~~~~~~~

why does it says memory limit exceeded for this code(problem E), isn't 60 * N sufficient

I was surprised to see my name appear in G's sample

Why does the E grade solutions in 5++ minutes????

If it graded them earlier, I could try using the LCM of the set

My first and second submission on C1 are wrong answer in pretest 1 (sample). I already check it locally and it gives me the correct output but somehow it gives different output on codeforces. I then submit basically the same solution in python for my third submission and it passed all the pretests. Does anybody know why this happened?

E is hard to figure out a simple solution. F is rather too simple?

Nice round to me anyway.

Is E just storing keys as coprime basis? Had this idea right after it ended :sob:

#include <bits/stdc++.h>
using namespace std;
int T,x,y;
int cnt(int x)
{
  int t=0;
  for(int i=1; i<=sqrt(x); i++)
    if(x%i==0)t++;
  if(sqrt(x)*sqrt(x)==x)return 2*t-1;
  return 2*t;
}
int main()
{
  cin>>T;
  for(int i=1; i<=T; i++)
  {
    cin>>x>>y;
    int p=abs(x-y);
    if(p==0)cout<<1<<'\n';
    else cout<<cnt(p)<<'\n';
    for(int i=1; i<=x; i++)cout<<1<<' ';
    for(int i=1; i<=y; i++)cout<<-1<<' ';
    cout<<'\n';
  }
  return 0;
}

This is my code to Problem B. Who can tell me why I Wa on test 2? Thank you so much.

Seems E misleads quite a some participants into storing primes/coprimes/keys with deletion, including me. How come can you guys come up with LCM?