Diego1149's blog

By Diego1149, history, 3 years ago, In English

Congratulations to the contestants that made it to world finals!!

I think this was one of the most competed regionals I've ever seen!

I feel like the quality of the problems has been going up in the past 10 years, so congratulations to all of the problem setters as well!

Scoreboard: https://scorelatam.naquadah.com.br/latam-2020/?fbclid=IwAR2L3sSAX_iD4oB01HVewrlnqZpbm4hVw6aEg-u4FOkZ0CutkFbtgLKPuMQ#

Here I give a subjective difficulty to the problems:

  • Easy: DLN
  • Medium-Easy: CEK
  • Medium-Hard: BFHJ
  • Hard: AGI
  • Very Hard: M

For Mexico solving all of Easy, Medium-Easy and 2 of the Medium-Hard would guarantee pass to world finals.

For other regions solving some/all of the Medium-Hard would also guarantee pass.

Every problem was solved during the contest by at least 1 team, congratulations to the teams that solved the harder problems!

DP was the most common topic it could be used in 6 of the problems, also for all DP problems (except L) they required a non-trivial transformation or optimization.

Notes on M: It was very hard, I think it was comparable in difficulty to https://open.kattis.com/problems/firstofhername. Would recommend finalists to solve this problem.

Link to editorial: https://github.com/Diego1149/ICPC-Latam-2020

For the difficulty in the editorial I assigned it based on the relative difficulty of the contest itself, meaning 1 to the easiest, 10 to the hardest.

Let me know if you have any questions or think I should update any of the editorials!

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3 years ago, # |
  Vote: I like it +23 Vote: I do not like it

Hack for your M solution.

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    3 years ago, # ^ |
      Vote: I like it +5 Vote: I do not like it

    That's true, thanks for noticing, I'll have to learn suffix array to be able to solve it properly :P