i hope i can get top 10 in this contest

I hope that this contest will be as good as CF Round #735. And maybe even better

Hope this educational round actually have balanced problems unlike the last edu round

Please don't start hopeforces again

28/07 -> July Cook-Off 2021

29/07 -> Codeforces Round #735

30/07 -> Educational Codeforces Round 112

31/07 -> July Lunchtime 2021

31/07 -> AtCoder Beginner Contest 212

01/08 -> Leetcode Weekly Contest 252

01/08 -> Codeforces Round 736

Raining Contests

I hope I can break my unconditional love with FSTs in this round.

:(

Please get me out of this losing streak. I'm doubling in rating loss each time.

y would anyone waste their time going to some trash unaccredited university, beyond me tbh

Good luck, guys!

I hope, I won't become turquoise again ^^

Good luck to everyone!

My first Contest as Expert , will try my best today to move up more !!

Hopefully this contest won't make you worry about your setters' safety.

I hope I can solve B XD

It's time to move up.
Good luck for everyone

Hope that there won't be any Bitwise-operators tonight.

I hope I will solve B in this contest

MikeMirzayanov I think something is wrong with my registration. It shows me as a official participant. Can you please fix it? I don't want to lose master.

Maybe there's sth wrong with Problem D.

How can a string which length is 1 can be changed to an "beautiful" string ?

just realized why A is the hardest problem ..

The announcement which came for C, should have come early. I was solving a different C, where Alice is looking for the maximum and then Bob goes with the minimum afterward.

Solved D at 01:50, so happy! ^__^

After giving yesterday's contest. This one feels so much better. Regained some confidence again. :)

When you solve A,C, and D but not B. Sigh...

B had more cases than law courts!

In my opinion, C was much easier than A and B. Thanks.

I think A,B is way more harder than C,D and E lol

I took 47 minutes to solve problem B (+ penalty), but 9 minutes to solve problem C and 15 minutes to solve problem D....

I'm so disappointed of myself Idk why my B solution is wrong :( :( I solved C easily I could have read D but I kept saying I will solve this B

Submission

Mathforces. 4 wrong submissions for A :(

score distribution is same for all problems? i have solve only C and D today but ranking is same who slove only A and B.

Nice contest, E is a very interesting problem.

Why was A and B (didn't read rest) so "heavily" math based compared to other general As and Bs? I'm surprised so many people got A, toughest A and B I've ever seen, also first time seeing both the starting two problems are math.. which is surprising considering most of the people can only do A and B (I'd expect something which has to more with programming than complete maths). IMO

Unfair constraints for python in problem D

same code for c++ https://mirror.codeforces.com/contest/1555/submission/124343239 got accepted but

python code got tle https://mirror.codeforces.com/contest/1555/submission/124338639

Headquarters MikeMirzayanov, Round Coordinator BledDest, one of the authors Errichto

please look into this.

a lot of case works in B :/

What the heck is wrong with guy who set up problem B. Like you really want the people to stop logical coding using their thinking skills and just spend 15 minutes considering all the cases like a donkey, and spend another 30 debugging when they get a penalty on the same code. Is this the way the best coding platform wants to evaluate its participants? If yes, then good luck/bye caseforces!

PS : i think the problem setters just wanted to minimize the nuumber of people who could attempt the good questions afterwards by just sticking them to this **** problem!

Problem F:

I used HLD to solve it. Can somebody please tell does there exists any approach without HLD?

could someone tell me whether i am wrong with these i have tried my own these problem link

void solve(vector<int>v[],int src,vector<int>&euler,unordered_map<int,int>&mp,int &counter) {
    euler.pb(src);
    if(mp.find(src) == mp.end()) mp[src] = counter;
    for(auto i:v[src]) {
        counter++;

        solve(v,i,euler,mp,counter);
        counter++;
        euler.push_back(src);
    }
}

void storeminimum(vector<int>&euler,int sq,vector<int>&sqrtd) {
    for(int i=0;i<euler.size();i++) {
        sqrtd[i/sq] = min(sqrtd[i/sq],euler[i]);
    }
}

void Main() {
    int t;
    cin>>t;
    for(int kk=1;kk<=t;kk++) {
        int n;
        cin>>n;
        vector<int>v[n+1];
        for(int i=1;i<=n;i++) {
            int m;
            cin>>m;

            for(int j=0;j<m;j++) {
                int a;
                cin>>a;
                v[i].pb(a);
            }
        }
        // first occurance 
        unordered_map<int,int>foc;


        // store euler path 
        vector<int>euler;
        int count = 0;

        solve(v,1,euler,foc,count);
        int sq = ceil(sqrt(euler.size()));
        vector<int>sqrtd(sq,INT_MAX);
        storeminimum(euler,sq,sqrtd);
        int q;
        cin>>q;
        cout<<"Case "<<kk<<":"<<endl;
        while(q--) {
            int a,b;
            cin>>a>>b;
            int ans = INT_MAX;
            int l=foc[a],r=foc[b];
            while(l<=r) {
                if(l%sq ==0 and l+sq-1<=r) {
                    ans=min(ans,sqrtd[l/sq]);
                    l+=sq;
                } else {
                    ans = min(ans,euler[l]);
                    l++;
                }
            }
            cout<<ans<<endl;
        }
    }
    
}

Are you kidding me? I used old version of problem F statement where cycle was simple if there weren't any repeated edges. And this is the only reason why I didn't get accepted during the contest. I've got accepted in 2 minutes after the round ended, so sad(

Can somebody please explain the solution of problem A?

Expected to become an expert today, will probably end up as a pupil...
Spent both the hours on Problem A and got 7 WAs, lol.

Solved 4 but still feeling worthless because of A and B xD

I spent 40 minutes on A and didn't have enough time to solve E ：(

B ruined my entire contest. Couldn't even read E though it was pretty doable. :((

124312667 this is my submission for problem B during the contest where i took the values float instead of long long and it gave WA. It gave a difference of 2 in one of the TC. 124345470 this is that same approach(everything same just changed float to long long) but got accepted....can any one pls explain why this happened. edit: by mistake initially i gave the link to wrong problem.

Can we do C using dfs ? I think it is the same as Cherry pickup II of leetcode ? please help.

But its a question afterall with a valid difficulty range for qstn. B. Also,its my fault that i assumed it to be something else. It actually didn't have much case work. Apologies..

Was thinking I'll regain Expert! But problem B exists lol, ate up huge amount of time :(

A clean(ish) solution for B.

import math
for _ in range(int(input())):
    W, H = map(int, input().split())
    x1, y1, x2, y2 = map(int, input().split())
    w, h = map(int, input().split())
    available_x = W + x1 - x2
    available_y = H + y1 - y2
    z = False
    ans = 1000000000000.0
    if(available_x >= w):
        current_available = max(x1 - 0, W - x2)
        t1 = float(max(0, w - current_available))
        ans = min(ans, t1)
        z = True
    if(available_y >= h):
        current_available = max(y1 - 0, H - y2)
        t2 = float(max(0, h - current_available))
        ans = min(ans, t2)
        z = True
    if(z):
        print(ans)
    else:
        print(-1)

We need to check for the number of free cells possible in both X and Y directions. (Free cells are the cells not occupied by the first table). If the number of free cells in ANY direction (X or Y) is greater than the number of cells needed for second table, then we can fit the second table in. The first table only needs to move horizontally or vertically to acommodate the second table, it will never have to move diagonally.

Is the rating predictor broken?

In reference to problem B 3 actions can be taken: 1. Rename the website to caseforces 2. Ban the guy who set it up from setting up future contests 3. The guy should have some self respect and delete his account

Should we be sad or happy in this case? :(

One of the best contests I have participated at in my life. Beautiful, Balanced and the Best

Actually problem B should be C and C should be B!

I admit I struggled at A took 30+ mins. I know it was quite easy but still.

hard contest only the first problem was easy

4 Div2 (with 2 Div1) Round, 2 Div3 Round, 2 Educational Round, 2 Div(1+2) Round, and 1 Global Round, Total of 11 Rounds held in this Month. So we can say July is the perfect month for all the contestants who like and enjoy every round of Codeforces. Thanks to Mike Mirzayanov and all the problem setters of this month <3

wonder how many guys copy-pasted their segment_tree for E from the Internet

A solution video for the first four questions of div 2

https://www.youtube.com/watch?v=NMSQ-uu59mQ

why to even use double in problem B as shown in sample output.

I misread problem D and thought that input string can contain any 26 letters of Latin alphabet and it is allowed to change any character of the string to one of the first 3 letters and couldn't solve that problem. Can this problem be solved?

Nice round with not easy nor really hard tasks E is especially good!

Is anybody know which testcase is in task b test 2 case 554? My solve fails on it and idk why... Here is link on it https://mirror.codeforces.com/contest/1555/submission/124358523 [](https://mirror.codeforces.com/contest/1555/submission/124358523) plz say what is wrong...