BledDest's blog

By BledDest, 2 weeks ago, In English

This round was prepared by Neon, adedalic, awoo, shnirelman and me.

Huge thanks to all of the testers: ashmelev, KIRIJIJI, PavelKunyavskiy, soup and Fanarill! Your feedback helped us balance this contest (and find a very stupid overflow bug I'm too ashamed to mention).

Thanks for participation, we hope you enjoyed the contest!

2011A - Problem Solving

Idea: BledDest, preparation: BledDest

Tutorial
Solution (Neon)

2011B - Shuffle

Idea: BledDest, preparation: BledDest

Tutorial
Solution (Neon)

2011C - Split the Expression

Idea: BledDest, preparation: BledDest

Tutorial
Solution (Neon)

2011D - Among Wolves

Idea: BledDest, preparation: adedalic

Tutorial
Solution (adedalic)

2011E - Rock-Paper-Scissors Bot

Idea: BledDest, preparation: Neon

Tutorial
Solution (Neon)

2011F - Good Subarray

Idea: BledDest, preparation: Neon

Tutorial
Solution (Neon)

2011G - Removal of a Permutation

Idea: BledDest, preparation: Neon

Tutorial
Solution (Neon)

2011H - Strange Matrix

Idea: BledDest, preparation: Neon

Tutorial
Solution (Neon)

2011I - Stack and Queue

Idea: shnirelman, preparation: awoo

Tutorial
Solution (awoo)
Solution 2 (awoo)
  • Vote: I like it
  • +22
  • Vote: I do not like it

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2 weeks ago, # |
  Vote: I like it +20 Vote: I do not like it

For problem I, it is fast enough to directly binary search on the persistent segment tree, in same complexity $$$O(\log^2 n)$$$ but (a lot) worse constant factor. This option is easier to implement (less problem specific thinking, more general implementation) than either of the two, especially if a optimised (array based, not object based) persistent segment tree is available to you.

My Contest Experience