Codeforces Round #813 (Div. 2) Editorial

Revision en22, by Vladithur, 2023-09-24 15:50:18

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

Solve count predictions (official div. 2)

1712A - Wonderful Permutation

Hint
Tutorial
Solution

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

1712B - Woeful Permutation

Hints
Tutorial
Solution

Bonus: try to prove the solution without the editorial!

1712C - Sort Zero

Hints
Tutorial
Solution

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

1712D - Empty Graph

Hints
Tutorial
Solution

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

1712E2 - LCM Sum (hard version)

Hints
Tutorial
Solution

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

1712F - Triameter

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...)

History

 
 
 
 
Revisions
 
 
  Rev. Lang. By When Δ Comment
en22 English Vladithur 2023-09-24 15:50:18 15635 Tiny change: '</spoiler>\n\n' -> '</spoiler>'
en21 English Vladithur 2022-08-15 19:45:50 2 Tiny change: ' x^2 + (x - 1)^2 - 1$' -> ' x^2 + (x + 1)^2 - 1$'
en20 English Vladithur 2022-08-14 03:44:18 63
en19 English Vladithur 2022-08-13 22:25:51 7 Tiny change: ' "people day when they' -> ' "people die when they'
en18 English Vladithur 2022-08-13 22:21:40 1131
en17 English Vladithur 2022-08-13 21:11:38 8
en16 English Vladithur 2022-08-13 20:42:48 0 (published)
en15 English Vladithur 2022-08-13 20:36:13 1 Tiny change: 'dded later\n\nPPS: I' -> 'dded later.\n\nPPS: I'
en14 English Vladithur 2022-08-13 20:19:04 57
en13 English Vladithur 2022-08-13 20:15:28 63
en12 English Vladithur 2022-08-13 20:14:16 20
en11 English Vladithur 2022-08-13 15:57:23 130
en10 English Vladithur 2022-08-13 01:41:30 56
en9 English Vladithur 2022-08-13 01:19:35 27
en8 English Vladithur 2022-08-13 01:14:31 2
en7 English Vladithur 2022-08-13 01:13:30 100
en6 English Vladithur 2022-08-13 01:12:33 943 Tiny change: 'n</spoiler\n\n<spoil' -> 'n</spoiler>\n\n<spoil'
en5 English Vladithur 2022-08-13 00:44:37 46
en4 English Vladithur 2022-08-13 00:43:33 1638 Tiny change: 'atorname{d'}(u, v) is ' -> 'atorname{d}'(u, v) is '
en3 English Vladithur 2022-08-13 00:24:57 1056 Tiny change: 'ary="Hint 2">\nSuppos' -> 'ary="Hint 3">\nSuppos'
en2 English Vladithur 2022-08-13 00:10:36 67
en1 English Vladithur 2022-08-13 00:07:53 1995 Initial revision (saved to drafts)