### _FireGhost_'s blog

By _FireGhost_, history, 6 months ago,

Congrats nightcrawler0112 for hitting the 200000000-th submission! Sadly it wasn't an AC...

• +157

By _FireGhost_, history, 9 months ago,

I want to rename my handle to FireGhost, which was occupied by this 4-year-inactive guy (link).

As far as I know from this post (link), I can request a handle of an inactive participant. Sorry for pinging you, MikeMirzayanov, but can you please take a look at my request? Thank you so much!

• +15

By _FireGhost_, history, 14 months ago,

Sparky_Master_WCH1226 would be really disappointed when he put a lot of efforts into shitposting but still lost his last place in one night

• +214

By _FireGhost_, 18 months ago,

Thank you for participating in the contest! We hope you enjoy the problems. You can also give feedback on each problem, it will help us much in future problem settings. By the way, feel free to share your solution!

1658A - Marin and Photoshoot

Hint 1
Hint 2
Tutorial
Solution
Feedback

1658B - Marin and Anti-coprime Permutation

Hint 1
Hint 2
Tutorial
Solution
Feedback

1658C - Shinju and the Lost Permutation

Hint 1
Hint 2
Hint 3
Tutorial
Solution
Feedback

1658D1 - 388535 (Easy Version)

Tutorial
Solution

1658D2 - 388535 (Hard Version)

Hint 1
Hint 2
Tutorial
Solution
Feedback

1658E - Gojou and Matrix Game

Hint 1
Hint 2
Tutorial
Solution
Feedback

1658F - Juju and Binary String

Hint 1
Hint 2
Tutorial
Solution
Feedback
• +87

By _FireGhost_, history, 3 years ago,

Recently, I've learned a powerful data structure: Suffix Automaton, and found out that it can solve lots of problems that can be solved with KMP/Z Function/Hash/... in average time complexity $O(n)$.

Now I'm curious to know, what are the pros/cons of this data structure? And is there any problems that can't be solved with Suffix Automaton but able to solve with others data structure? Thank you in advance!

(for people who doesn't know this data structure: Link 1, Link 2)

• +18