Vladithur's blog

By Vladithur, history, 11 months ago, In English

Hope you liked the problems!

1856A - Tales of a Sort

Hints
Tutorial
Solution
Feedback

1856B - Good Arrays

Hints
Tutorial
Solution
Feedback

1856C - To Become Max

Hints
Tutorial
Solution
Feedback

1856D - More Wrong

Hints
Tutorial
Solution
Feedback

1856E1 - PermuTree (easy version)

Hints
Tutorial
Solution
Feedback

1856E2 - PermuTree (hard version)

Hints
Tutorial
Solution
Feedback

UPD: Tutorial for E1 has been added.

UPD2: Tutorial for E2 has been added.

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By Vladithur, history, 11 months ago, In English
Hi, Codeforces!

Alexdat2000, Igorfardoc, and I are pleased to invite you to our Codeforces Round 890 (Div. 2) при поддержке Constructor Institute, which will be held on 05.08.2023 17:35 (Московское время). This round will be rated for participants with a rating lower than 2100.

We would like to thank:

You will be given 5 problems, one of which is divided into two subtasks, and you will have 2 hours to solve them.

One of the problems will be interactive, so please read the guide for interactive problems if you are not familiar with it.

The score distribution is 500 — 750 — 1250 — 2000 — (1500 — 1500)

UPD: Tutorial

UPD2: Congratulations to the winners!

Div. 2:

  1. AMDAM
  2. Aoi_Minoa
  3. baojiaopicua
  4. Valaki2
  5. JCY_

Div. 1:

  1. neal
  2. maspy
  3. A_G
  4. AmazingTalker_Frank
  5. heno239

We are thrilled to share some exciting news with you! We are teaming up with our partner, Constructor Institute in Schaffhausen, Switzerland, to bring you an amazing opportunity: a round supported and organized in collaboration with Constructor Institute, where you can explore Master's programs in Switzerland. Now we pass the floor to our partner.

CU

Hello, Codeforces community!

Constructor Institute in Schaffhausen (Switzerland) is pleased and proud to have the opportunity to support the round on Codeforces. We invite you to participate in it!

If you are passionate about studying in Switzerland and pursuing a Master’s degree, we encourage you to fill out the form to initiate the application process and scholarship interview. Our Institute representatives will be in touch with you to guide you through the next steps.

We offer two Master programs, both taught in English, with flexible duration of 1.5 or 2 years full-time:

Our Master's programs open doors to a world of opportunities. Many of our students have secured high-profile roles in multinational companies in Switzerland and across the globe. Additionally, our programs also serve as an excellent preparation for Ph.D. research in fields such as software engineering, cybersecurity, artificial intelligence, and other advanced topics.

​​We understand that financing your education can be a concern, and to support your journey, we are offering the following scholarships:

  • Tuition waiver scholarships — 20,000 CHF per year, covering the cost of tuition fees.
  • Full scholarships — 20,000 CHF per year, covering the cost of tuition fees, along with a monthly stipend of 2,000 CHF to assist with living expenses in Schaffhausen.

Both scholarships are non-repayable, providing you with financial peace of mind.

To learn more about Constructor Institute and its programs, visit our webpage.

Eligibility for the programs and its available scholarships:

  • You have obtained or you will obtain a Bachelor’s degree in Computer Science, Software Engineering, Physics, or a related field before the program starts.

To express your interest in this opportunity, please complete the form:

Complete the Form

We wish you good luck in the competition and enjoy solving the problems.

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By Vladithur, history, 18 months ago, In English

Hope you liked the problems!

(from thanhchauns2) Before the round starts

1768A - Greatest Convex

Author: thanhchauns2

Hints
Tutorial
Solution
Feedback

1768B - Quick Sort

Author: Vladithur Preparation: Vladithur and Alexdat2000

Hints
Tutorial
Solution
Feedback

1768C - Elemental Decompress

Author: thanhchauns2

Hints
Tutorial
Solution
Yet another better solution
Feedback

1768D - Lucky Permutation

Author: Vladithur Preparation: Vladithur and Alexdat2000

Hints
Tutorial
Solution
Feedback

1768E - Partial Sorting

Author: thanhchauns2

Hints
Tutorial
Solution
Feedback

1768F - Wonderful Jump

Author: Vladithur Preparation: Vladithur and Alexdat2000

Hints
Tutorial
Solution
Shorter solution (tfg)
Feedback

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By Vladithur, history, 22 months ago, In English

Thanks for participating in the round, we hope you liked the problems!

Solve count predictions (official div. 2)

1712A - Чудесная перестановка

Hint
Tutorial
Solution

Bonus: solve for every $$$k$$$ from $$$1$$$ to $$$n$$$ for $$$n \le 10^5$$$.

1712B - Жалкая перестановка

Hints
Tutorial
Solution

Bonus: try to prove the solution without the editorial!

1712C - Очередная задача про сортировку

Hints
Tutorial
Solution

Bonus: solve for when $$$a_i$$$ can also be negative.

1712D - Пустой граф

Hints
Tutorial
Solution

Bonus: solve for every $$$k$$$ from $$$1$$$ to $$$n$$$.

1712E2 - Сумма НОК (сложная версия)

Hints
Tutorial
Solution

Bonus: solve the problem in $$$\mathcal{O}((n + t) \log n)$$$ or better.

1712F - Триаметр

Hints
Tutorial
Solution

Bonus: solve for $$$n, q \le 10^6$$$.

Don't forget to rate the problems!

Problem Feedback

PS: Solution codes probably will be added later.

UPD: explanations of the references:

Click here

UPD2: added solution codes (better late than never...)

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By Vladithur, history, 23 months ago, In English
Hi, Codeforces!

Igorfardoc and I are pleased to invite you to our Codeforces Round 813 (Div. 2), which will be held on Aug/13/2022 17:35 (Moscow time). This round will be rated for participants with rating lower than 2100.

We would like to thank:

You will be served 6 problems, one of which is divided into two subtasks, and you will have 2 hours and 15 minutes to sample them.

Hope you don't choke 😋

The score distribution is 500 — 1000 — 1500 — 2000 — (2000 — 750) — 3500

PS

UPD: Tutorial

UPD2: Congratulations to the winners!

Div. 2:

  1. iztrax
  2. TrungNotChung
  3. Akemi-Homura
  4. bajablast
  5. __NONE__

Div. 1:

  1. tourist
  2. m_99
  3. jiangly
  4. LJC00118
  5. sjc061031

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By Vladithur, history, 2 years ago, In English

You can also find video editorials for problems B-D on ak2006's Youtube channel!

1632A — ABC

Hint 1
Hint 2
Solution
Solution codes

1632B — Roof Construction

Hint 1
Hint 2
Solution
Solution codes

1632C — Strange Test

Hint
Solution
Solution codes

1632D — New Year Concert

Hint 1
Hint 2
Hint 3
Solution
Solution codes

1632E2 — Distance Tree (hard version)

Hint 1
Hint 2
Hint 3
Hint 4
Solution
Solution codes

P. S. Solution codes will be published a little later.

P. P. S. Do not forget to evaluate the problems in the announcement.

UPD: Solution codes have been posted.

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