n0sk1ll's blog

By n0sk1ll, history, 3 months ago, In English

Hello, Codeforces!

BULLMCHOW and I are glad to invite you to Codeforces Round 910 (Div. 2), which will start on Nov/19/2023 17:35 (Moscow time). You will be given 6 problems and 2 hours to solve them.

The round will be rated for participants of Division 2 with a rating lower than 2100. Division 1 participants can participate unofficially.

All problems are invented and prepared by BULLMCHOW and me. Special thanks go to Sofija06 and NemanjaSo2005, our two most dedicated testers. We would also like to honor:

We are looking forward to your participation!

UPD1: The score distribution is $$$500 — 1250 — 1750 — 1750 — 2000 — 2500$$$.

UPD2: Editorial

UPD3: Congratulations to the winners!

  1. hitonanode
  2. Rubikun
  3. femboy-wannabe
  4. potato167
  5. Golovanov399
  6. A_G
  7. AmazingTalker_Frank
  8. Geothermal
  9. StarSilk
  10. Farhod

UPD4: Also, congratulations to the Div. 2 winners!

  1. femboy-wannabe
  2. Top2Greece
  3. hoiii
  4. KaiAngel
  5. Nguyen_Mai_Huong
  6. lunchbox
  7. bobbilyking
  8. y_x_c
  9. supercambrian
  10. MeGustaElArroz23

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By n0sk1ll, history, 5 months ago, In English

1898A - Milica and String

Author: n0sk1ll

Hint
Solution
Bonus

1898B - Milena and Admirer

Author: BULLMCHOW & n0sk1ll

Hint
Solution
Bonus

1898C - Colorful Grid

Author: n0sk1ll

Hint
Solution
Bonus

1898D - Absolute Beauty

Author: n0sk1ll

Hint
Solution
Bonus

1898E - Sofia and Strings

Author: BULLMCHOW

Hint
Solution
Bonus

1898F - Vova Escapes the Matrix

Author: n0sk1ll

Hint
Solution
Bonus

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By n0sk1ll, 14 months ago, In English

Hello Codeforces!

I am pleasured to invite you to take part in Hello 2023, which will take place in Jan/03/2023 17:35 (Moscow time)!

This round consists of $$$8$$$ tasks waiting for you to solve in $$$150$$$ minutes, and will be rated for everyone!

As an author, please allow me to express my sincere thanks to:

I hope you enjoy our problems and have a wonderful $$$2023$$$!

UPD1: New score distribution is $$$500 — 750 — 1250 — 1500 — 2250 — 2250 — 2750 — 4000$$$.

UPD2: Editorial is out!

UPD3: Congratulations to the winners!

  1. Benq
  2. tourist
  3. Rewinding
  4. hitonanode
  5. jiangly_fan
  6. jiangly
  7. duality
  8. maroonrk
  9. Maksim1744
  10. DearMargaret

UPD4: Also, congratulations to the first solves of each problem!

  1. Geothermal with 187728121
  2. tourist with 187728792
  3. tourist with 187733377
  4. MEGAcrusher5000 with 187739126
  5. tourist with 187755451
  6. tourist with 187775898
  7. TLEwpdus with 187757570
  8. Rewinding with 187815792

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Announcement of Hello 2023
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By n0sk1ll, 14 months ago, In English

1779A - Hall of Fame

Author: n0sk1ll

Hint
Solution
Bonus Problem

1779B - MKnez's ConstructiveForces Task

Author: n0sk1ll

Hint 1
Hint 2
Solution
Bonus Problem

1779C - Least Prefix Sum

Author: n0sk1ll

Hint 1
Hint 2
Solution
Bonus Problem

1779D - Boris and His Amazing Haircut

Author: n0sk1ll

Stupid Hint
Hint
Solution
Bonus Problem

1779E - Anya's Simultaneous Exhibition

Author: n0sk1ll

Hint
Lemma 1
Lemma 2
Solution
Bonus Problem

1779F - Xorcerer's Stones

Author: n0sk1ll

Hint 1.1
Hint 1.2
Hint 1.3
Hint 2.1
Hint 2.2
Solution
Bonus Problem
Bonus Problem Hint

1779G - The Game of the Century

Author: Giove

Hint
Solution
Bonus Problem

1779H - Olympic Team Building

Author: n0sk1ll

Huge thanks to dario2994 for helping me solve and prepare this problem.

Hint 1
Hint 2
Fake Solution
Lemma
Solution
Bonus Problem

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Tutorial of Hello 2023
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By n0sk1ll, history, 21 month(s) ago, In English

1689A - Lex String

Author: wxhtzdy

Hint
Solution
C++ Code

1689B - Mystic Permutation

Author: n0sk1ll

Hint 1
Hint 2
Solution
C++ Code (Main solution)
C++ Code (O(n) solution)

Riblji_Keksic found the O(n) solution.

1689C - Infected Tree

Author: n0sk1ll

Hint 1
Hint 2
Solution
C++ Code

1689D - Lena and Matrix

Author: n0sk1ll

Hint
Solution
C++ Code

1689E - ANDfinity

Author: wxhtzdy

Stupid Hint
Hint 1
Hint 2
Hint 3
Solution
C++ Code

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