### Imakf's blog

By Imakf, history, 5 weeks ago,

1890A - Doremy's Paint 3

idea: Cocoly1990

Solution
Code

1890B - Qingshan Loves Strings

idea: Imakf

Solution
Code

1889A - Qingshan Loves Strings 2

idea: Imakf

Solution
Code

1889B - Doremy's Connecting Plan

idea: Cocoly1990

Solution
Code

1889C2 - Doremy's Drying Plan (Hard Version)

idea: waaitg, Imakf

Easy Solution
Hard Solution
Code

1889D - Game of Stacks

idea: waaitg

Solution
Code

1889E - Doremy's Swapping Trees

idea: waaitg

Solution
Code

1889F - Doremy's Average Tree

idea: waaitg, Imakf

Solution
Code
• +174

By Imakf, history, 6 weeks ago,

Hello, Codeforces!

waaitg, Cocoly1990 and I are glad to invite you to Codeforces Round 906 (Div. 1) and Codeforces Round 906 (Div. 2), which will take place on Oct/28/2023 17:35 (Moscow time). In both divisions, you will be given 6 problems and 2 hours and 30 minutes to solve them all. Note that one of the tasks is split into two subtasks.

We would like to thank:

Score distribution:

Div. 2: $500$ — $750$ — $1250$ — $2000$ — $(1250 + 2500)$ — $3250$
Div. 1: $750$ — $1250$ — $(750 + 1500)$ — $2000$ — $3500$ — $3500$

As always, wish you all get a non-negative delta in this round!

UPD1: Editorial

UPD2: congratulations to the winners!

Winners and first solves
• +544

By Imakf, history, 12 months ago,

1764A - Дореми и краски

idea: Cocoly1990

Solution
Code

1764B - Дореми и идеальный урок по математике

idea: waaitg

Solution
Code

1764C - Дореми и строительство города

idea: waaitg

Solution
Code

1764D - Дореми и игра с колышками

idea: Imakf

Solution
Code

1764E - Дореми и числовая прямая

idea: Imakf

Solution
Code

1764F - Дореми и экспериментальное дерево

idea: Cocoly1990

Solution
Code

1764G3 - Дореми и идеальная пара по структурам данных (сложная версия)

idea: waaitg

Solution
G1 Code
G3 Code

1764H - Дореми и краски 2

idea: Imakf, waaitg and errorgorn

Solution
Code
• +121

By Imakf, history, 12 months ago,

Hello Codeforces!

On Nov/26/2022 17:05 (Moscow time) we will host Codeforces Global Round 24. Note the unusual time of the round.

It is the sixth round of a 2022 series of Codeforces Global Rounds. The rounds are open and rated for everybody.

The prizes for this round:

• 30 best participants get a t-shirt.
• 20 t-shirts are randomly distributed among those with ranks between 31 and 500, inclusive.

The prizes for the 6-round series in 2022:

• In each round top-100 participants get points according to the table.
• The final result for each participant is equal to the sum of points he gets in the four rounds he placed the highest.
• The best 20 participants over all series get sweatshirts and place certificates.

Thanks to XTX, which in 2022 supported the global rounds initiative!

The problems were written and prepared by Cocoly1990, waaitg and Imakf. 👀👀👀

We would also like to thank:

Round Information:

• Duration: 2 hours and 30 minutes 🔥🔥🔥
• Number of problems: 8 problems, one split into 3 subtasks 🤯🤯🤯
• Score distribution: $500$ — $1000$ — $1500$ — $1750$ — $2250$ — $2250$ — $(2000+500+500)$ — $3500$ 🤤🤤🤤
• There is an interactive problem, so please see the guide of interactive problems if you are not familiar with it. 🤭🤭🤭

As always, hope you all gain non-negative ratings $\Delta$ in this round! 🍾🍾🍾

UPD1: Editorial

Announcement of Codeforces Global Round 24
• +513

By Imakf, history, 3 years ago,

The jury solutions will be updated later.

The jury solution is updated now.

1496A - Split it!

Idea: waaitg

Solution (Imakf)

1496B - Max and Mex

Idea: waaitg

Solution (waaitg)

1495A - Diamond Miner

Idea: smg23333

Solution (smg23333)

1495B - Let's Go Hiking

Idea: waaitg

Solution (waaitg)

1495C - Garden of the Sun

Idea: Imakf

Solution (Imakf)

1495D - BFS Trees

Idea: waaitg, Daniel_yuan, isaf27

Solution (Daniel_yuan)

1495E - Qingshan and Daniel

Idea: Imakf

Solution (Imakf)

1495F - Squares

Idea: waaitg

Solution (waaitg)
• +160

By Imakf, history, 3 years ago,

Hello, Codeforces!

Daniel_yuan, waaitg, smg23333 and I are glad to invite you to Codeforces Round 706 (Div. 1) and Codeforces Round 706 (Div. 2), which will take place on Mar/10/2021 15:05 (Moscow time). Note the unusual time of the round. In both divisions, you will be given 6 problems and 2 hours to solve them all.

We would like to thank:

Score distribution will be announced before the round.

Hope you all gain positive ratings $\Delta$ in this round!

UPD1: Score distribution is

Div. 2: $500-1000-1500-2000-2500-3000$

Div. 1: $500-1000-1500-2000-2500-3250$

UPD2: Editorial

UPD3: Congratulations to the winners:

Div 1:

Div 2:

• +580

By Imakf, history, 3 years ago,

My friends and I proposed a contest 4 months ago and received replies recently. It should be a happy thing. Unfortunately, today, one of my friends doesn't know English very well and he really pushes the "MAKE IT PRIVATE" button. Then the proposal is cancelled TAT. Of course we don't want to wait for another 4 months. But all of us don't know how to handle this situation. We felt really sorry for making such a stupid mistake.

We have reproposed the contest. It would be good if the coordinator could help us. Thanks, and sorry again.

• +187

By Imakf, history, 3 years ago,

Just now my friend(parallelist) found a wrong solution(83183287) of an old problem. He tried to hack it but couldn't find the hack button. I guess that it's because he seldom participates in contests so he ask me to do it and gave me his hack tests. But there is NO hack button either on my screen. "Maybe I should solve this problem first?" I think. Then I do a copy paste to get AC. Well, there's still no hack button.

I am sorry for my friend, wondering if it is true that on Codeforces, you can not make a hack on an old problem? Thanks in advance.

• +11

By Imakf, history, 4 years ago,

Hello codeforces!

CSP-J/S(Certified Software Professional-Junior/Senior) of China ended. CSP-J/S (or you can say NOIp ,but it has been dead) was held by OI rules. In OI rules, every problem has the same score distribution $100$ points. In one problem, there is several testdatas (like $10$ ,$20$ or $25$). Every testdata has the same score distributions. Once you pass a testdata, you can get the score. You can submit your code during the contest, but can't see the result. The organizer will judge all the programs together after contest.

I'd like to share the problems of CSP-S here! Hope you guys enjoy. Don't mind my poor English, I spent a whole afternoon translating.

D1T1 code
D1T2 brackets
D1T3 tree
D2T1 meal
D2T2 partition
D2T3 centroid
• +71