As the author of two problems I'd like to ask you guys to read all the problems and not to rage quit if you dislike a problem too much

Is it rated?

As a tester, Problems are really good and interesting. Good luck!!

I see low_ as a tester. Congrats!!

As a tester, I approve this contest.

In before

If you don't want failed system testing, submit correct code

I am able to register for official contest too is it ok .

Which One should I register for uprating? (rating ability about 1900) Could anyone give me some suggestion

Take care of the unusual time.

Just noticed that russian comments are visible in russian transcripted mode with english comments .

HALA Madrid!!!

Notice the unusual starting time,Golovanov399,I think this should be mentioned

Notice the Unusual time. GOOD LUCK :)

Oh my
Notice that it is based on the olympiad (kind of) for Russian students of 8-11 grades.
For some reason it is not written so explicitly in the English page. But better be prepared

Judging from the announcement, the official round is not rated, and the div1 and div2 versions are rated. Is my understanding correct?

As a tester, I just wanted to say I love this community :D and thank you KAN for reaching out and giving me this opportunity

I'm still seeing a lot of upcoming future contest :3

I hate problems

As a tester, I highly recommend writing this round.

An interesting thing happened. Yesterday，my rating was still 1900 + and I was able to sign up for div1. After the end of yesterday's contest, I dropped to 1800 +, which should not be able to fight div1, but I was still in the div1 queue. So do you think I should quit div1. :) (https://mirror.codeforces.com/contestRegistrants/1434)

As a tester , problems are balanced+Cf-Level and great effort by setters . ATB.

Who can tell me if the problems in the 3 contests with same preliminary costs are a same problem? Thanks a lot! By the way, I tried to register for the Div.2 contest as usual, but I failed and got the information "Rating should be between 0 and 1,899 in order to register for the contest". I remembered that the Div.2 contests were for users whose ratings were between 0 and 1,999 (or 2,100) usually. Was it common for this situation?

rated？？？

Today there seems to be a very long queue. I hope it is fixed before the round.

I know this is not the right place to ask but I'm facing problem with codeforces. My codeforces from last night is loading in russian and every time it takes few seconds to translate the page into english but its happening every single time for every page of codeforces.

Also i'm seeing few keywords change in codeforces like "Accepted" to "Complete Solution" and "Submission" to "Attempts". Can anyone help me out? Apologies for posting it in this blog but this blog is active so I asked here.

am I the only one who reads all the comments and vote them ? codeforces comments section is really fun to me! :v

Could anybody tell me why the registration for Div. 2 is already closed? Is it because of some participant limit? You can still register for Div. 1...

I didn't expect such problems. Typing it in the middle of contest can show you my frustration level..

Anyone else suspicious of D being "well known" problem in China?

contest has made me wonder if i'm way dumber than I though I was ;-;

After 1396C - Monster Invaders, I decided to not read tasks with monsters/enemies and more than 3 parameters in input. It is not good for my mental health.

1B/2D is easier than 1A/2C.

I don't know why, but it seems that the contest is too friendly to Chinese OIers.

Almost half of the first 50s are Chinese OIers...

How to solve 2C?

what's pretest 9 in div2 C?

why my solution is getting tle https://mirror.codeforces.com/contest/1435/submission/96683823

What's the hack point of Div.1B?

Div 2C, What was I missing, anyone please help?

What was pretest 9 on D2C? I noticed most solutions that failed 2C got WA on test 9. (so did I T.T)

How to solve Div2C/1A?

Div 2 D was pretty easy ! just hope that it has strong pretest.

why my sol for div2 D getting tle https://mirror.codeforces.com/contest/1435/submission/96683823

Holy shit this is the first time I solved all problems in a div2 contest DAYUM.

GOD of codeforces, please make it so I don't fail any system tests, please!!!

update: All tests passed :)

how to approach C?

How to approach C?

was ternary search going to help in any way?

Thank you guys for the Div2 C really enjoyed doing it :)

How to solve div2 B?

Why TL in C is too strict. My O(NlogN) gives TL on test 9. Why? Why?
link

Today's div2 C was very similar to this: https://www.geeksforgeeks.org/find-smallest-range-containing-elements-from-k-lists/

Can someone give some hints for Div1 D?

Man I thank authors for problem D2C .. really felt a super satisfied after solving that problem

Div1 ABC were selected while high on something, huh? A is a good problem but seems way harder than a typical A, B is just a basic idea and implementation (I'd swap them) and C is just some weird ugly adhoc. Call it personal preference, but that is a ragequit problemset.

At least D is very interesting. My solution is based on proving that we don't miss the best path if we pick a diameter and use one of its vertices as one end of our path. Next, we can assign a state $$$X_v$$$ to each vertex $$$v$$$ where for a stone edge $$$(u, v)$$$, $$$X_u \oplus X_v = 1$$$. That means we're dealing with 2 fixed rooted trees and queries "invert all $$$X$$$ in a subtree" and "find the deepest vertex with $$$X=0$$$", which can be done with a segment tree in $$$O(N+Q\log{N})$$$.

What was pretest 11 on div2 D?

Was C precomputation with a small dp of prefix and suffix?

.Can anyone tell that my solution will pass or not . Solution link. Code Link

Pre-thanks to the reader of the comment!

Why is Div1C a routine maxima finding problem?

Can someone please help me in 2C/1A? I formed an array of all possible ferrets I can chose by also storing the index for which I get that ferret. After that I just iterate over all possible values of ferret using two pointer. Whenever I get a condition that the current indices have all notes atleast one, I consider it and increase the lower indice by one. ANd whenever I dont comeup with such a situation, I increase the upper indice by one. Can someone please tell where did I go wrong?

#include <bits/stdc++.h>


 #define vi vector<int>
 #define tests int t; cin>>t; while(t--)
 #define ll long long
 #define vll vector<long long>
 #define srt(v) sort(v.begin(), v.end())
  #define srtg(v) sort(v.begin(), v.end(), greater<int> ())
  #define FOR(k, n) for(int k=0; k<n; k++)
 #define pb push_back
 #define yes cout<<"YES"<<endl
 #define no cout<<"NO"<<endl
 #define printarr(v) for(auto& x : v) cout<<x<<" "; cout<<endl

using namespace std;



const int MOD = 1000000007;


bool sortcol(const vi v1, const vi v2){ return v1[0] < v2[0]; }

void solve() {
    
   vi strings(6);
   for(auto& x : strings) cin>>x;
   int n;
   cin>>n;
   
   vi v(n);
   for(int i=0; i<n; i++) cin>>v[i];
   vector<vi> posval;
   
   for(int i=0; i<n; i++){
      
           for(int j=0; j<6; j++){
                posval.pb(vector<int> (2));
              //  posval.pb({v[i]-string[j], i});
                int k=posval.size();
                posval[k-1][0]=v[i]-strings[j];
                posval[k-1][1]=i;
           }
   }
   
   sort(posval.begin(), posval.end(), sortcol);
   
   
   
   int i=0, j=0; 
   int p=posval.size();
   vi cnt(n);
   bool one=false;
   int left=n;
   int miny=MOD;
   while(i<p&&j<p){
        cnt[posval[j][1]]++;
        if(cnt[posval[j][1]]==1) left--;
        if(left==0) one=true;
        if(one==false){
            j++;
            continue;
        }
        if(one == true){
            miny=min(posval[j][0]-posval[i][0], miny);
            cnt[posval[i][1]]--;
            if(cnt[posval[i][1]]==0){
                left++;
                one=false;
            }
            i++;
        }
   }
   //for(int i=0; i<p; i++) printarr(posval[i]);
   cout<<miny<<endl;
}


int main() {

    ios_base::sync_with_stdio(false);
    cin.tie(0);
    
   
    
      //  tests
        solve();


    return 0;
}

You can copy-paste problem Div.1D from either here or here, and then add 5 new lines to adjust it to this problem. Too sad I read Div.1E first. =/

Seems that m2.codeforces.com had periodically been unstable during contest. Why is that?

(Had it been accessible, I would perhaps have one more problem Pretest Passed... sad story)

In div.2,why C C and why E E?:/

Problem D was way easier than C, I wasted 60-75 min on C and then started D and it took only 10 min. Even no of ac submissions say it. If D and C were interchanged D would have had 1000+ and C would have 400 and would have been reasonable.

How to solve A?

Learnt 2 lessons

1)If you see a problem which even IM's are struggling to get AC, skip that and move to the next problem (Iam looking at you 2C/1A)

2)If you keep on getting WA on a particular test case, instead of debugging do ctrl + A + del start from scratch

Bad ordering of questions. Why is D 500 points more than C?

Is there a DP solution for 2C, two pointer approach worked for me but I wasted too much time thinking about a dp solution.

Golovanov399 reporting cheating cases this and this
Even their handles are similar lol.

MikeMirzayanov please take care of this, he is ranked 4 in div2.

Waiting eagerly to see ecnerwala solving 2C/1A in his stream .

There seems to be some issue with java platform. Problem B is giving TLE for a simple O(n*m) solution.

why my sol for div2 D getting tle https://mirror.codeforces.com/contest/1435/submission/96683823 please help..

haha )) :

Tired of weak pretests now. 4 FST in last 3 contests. -_-

If you struggle with C for 1.5 hour, maybe you should read D... The more you know

From now on I won't ever trust any tester saying than he approves the contest/loves the problems/finds them interesting. The same goes for "don't rage quit the contest" — today it was the best possible tactical move.

I wonder why tourist's submissions got skipped except the first one(which took part in the systest).... __ Just be curious, shouldn't the last submission count into the systest(instead of the first one)? Or I missed something?

→https://mirror.codeforces.com/blog/entry/84056?#comment-714979

I have solved only two problems in today's contest. One of them got tle in main tests. Please god let me know is it a dream?:()

submissions 96704396 and 96676432 are exactly the same code, but one of them passed while the other got TLE on test 17.

I: Nice! I finally passed Div1.D!

System Test: No, you didn't.

please anyone check to it

my solution is O(n) for div2B and it still shows TLE what i am doing wrong how can i further decrease time complexity people have submitted in O(n) and they are accepted ?? Help

https://mirror.codeforces.com/contest/1435/submission/96705858

How to create a large number of [TLE failed system test] :

1. Set a tough time limit.

2. Don't put into pretests the test on which most solutions run slowest.

3. Enjoy FSTs.

:)