zltzlt's blog

By zltzlt, history, 4 months ago, In English

(After 3 months) Hello again, Codeforces!

We are glad to invite you to participate in Codeforces Round 968 (Div. 2), which will start on Aug/25/2024 17:35 (Moscow time). You will be given 6 problems and 2 hours to solve them. Two problems are divided into two subtasks.

This round will be rated for participants whose rating is below 2100. Participants with higher rating can participate unofficially.

The problems were authored and prepared by me.

I would like to thank:

Scoring distribution: $$$500 - 750 - 1000 - (1000 - 1250) - (1750 - 1000) - 2500$$$.

Good luck & Have fun!

UPD1: Editorial and also Simplified Chinese Editorial are out.

UPD2: Congratulations to the winners!

Div. 2:

  1. Empty_Dust
  2. cz_yxx
  3. Hosen_ba
  4. farkon00
  5. _minhduccp

Div. 1 + Div. 2:

  1. jiangly
  2. ksun48
  3. kotatsugame
  4. Sugar_fan
  5. Golovanov399

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By zltzlt, history, 4 months ago, In English

Thank you for your participation!

Rating Predictions

2003A - Turtle and Good Strings

Hint
Solution
Code

2003B - Turtle and Piggy Are Playing a Game 2

Hint
Solution
Code

2003C - Turtle and Good Pairs

Hint
Solution
Code

2003D1 - Turtle and a MEX Problem (Easy Version)

Hint
Solution
Code

2003D2 - Turtle and a MEX Problem (Hard Version)

Hint
Solution
Code

2003E1 - Turtle and Inversions (Easy Version)

Hint 1
Hint 2
Solution
Code

2003E2 - Turtle and Inversions (Hard Version)

Hint
Solution
Code
Bonus

2003F - Turtle and Three Sequences

Hint 1
Hint 2
Solution
Code

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By zltzlt, history, 6 months ago, In English

Hello, Codeforces!

We are glad to invite you to participate in Codeforces Round 949 (Div. 2), which will start on May/31/2024 13:05 (Moscow time). Note the unusual start time of the round. You will be given 6 problems and 2 hours to solve them.

This round will be rated for participants whose rating is below 2100. Participants with higher rating can participate unofficially.

The problems were authored and prepared by sinsop90, yinhee and me.

I would like to thank:

Scoring distribution: $$$500 - 1000 - 1500 - 2000 - 2500 - 3500$$$.

Good luck & Have fun!

UPD: Congratulations to the winners!

Div 2:

  1. cyb0101
  2. Feduk_Pro_Spb
  3. whale_0086
  4. graphcity
  5. grass8cos

Div. 1 + Div. 2:

  1. maspy
  2. Savior-of-Cross
  3. Rubikun
  4. femboy-wannabe
  5. turmax

Editorial and also Simplified Chinese Editorial are out.

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By zltzlt, history, 6 months ago, In English

Thank you for participating! Sorry for being much harder than usual Div. 2 :( But we still hope you find some of our problems interesting.

Rating predictions (Inspired by sum's editorial)

1981A - Turtle and Piggy Are Playing a Game

Idea: zltzlt

Hint 1
Hint 2
Solution
Code

1981B - Turtle and an Infinite Sequence

Idea: zltzlt

Hint 1
Hint 2
Solution 1
Solution 2
Code for Solution 1
Code for Solution 2

1981C - Turtle and an Incomplete Sequence

Idea: zltzlt

Hint 1
Hint 2
Solution
Code

1981D - Turtle and Multiplication

Idea: sinsop90

Hint 1
Hint 2
Solution
Code

1981E - Turtle and Intersected Segments

Idea: zltzlt
Developed by 244mhq.

Hint 1
Hint 2
Solution
Code

1981F - Turtle and Paths on a Tree

Idea: yinhee
Developed by 244mhq and zltzlt.
Thanks AFewSuns and crazy_sea for discovering Solution 2, which runs faster than Solution 1!

Hint 1
Hint 2
Solution 1
Solution 2
Code for Solution 1
Code for Solution 2

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