Editorial of Educational Codeforces Round 4

Revision en1, by Edvard, 2015-12-25 22:41:53

612A - The Text Splitting

Let's fix the number a of strings of length p and the number b of strings of length q. If a·p + b·q = n, we can build the answer by splitting the string s to a parts of length p and b parts of length q, in order from left to right. If we can't find any good pair a, b then the answer doesn't exist. Of course this problem can be solved in linear time, but the constraints are small, so you don't need linear solution.

Complexity: O(n2).

612B - HDD is Outdated Technology

You are given the permutation f. Let's build another permutation p in the following way: pfi = i. So the permutation p defines the number of sector by the number of fragment. The permutation p is called inverse permutation to f and denoted f - 1. Now the answer to problem is .

Complexity: O(n).

612C - Replace To Make Regular Bracket Sequence

612D - The Union of k-Segments

612E - Square Root of Permutation

612F - Simba on the Circle

Tags education round 3, editorial

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  Rev. Lang. By When Δ Comment
en8 English Edvard 2015-12-26 05:53:25 53
en7 English Edvard 2015-12-26 05:48:46 72
en6 English Edvard 2015-12-26 05:41:45 31
en5 English Edvard 2015-12-26 05:35:55 1853
ru7 Russian Edvard 2015-12-26 05:24:25 5 Мелкая правка: 'i=min_j (z[j] + d_{i, j})$, по в' -> 'i=min_j (z_j + d_{ij})$, по в'
en4 English Edvard 2015-12-26 05:16:39 787
ru6 Russian Edvard 2015-12-26 05:16:14 32
en3 English Edvard 2015-12-26 05:05:37 1032
en2 English Edvard 2015-12-26 04:57:17 1253
ru5 Russian Edvard 2015-12-26 04:56:48 136
en1 English Edvard 2015-12-25 22:41:53 982 Initial revision for English translation
ru4 Russian Edvard 2015-12-25 22:29:23 1 Мелкая правка: 'v+od_{vi}). Теперь л' -> 'v+od_{vi})$. Теперь л'
ru3 Russian Edvard 2015-12-25 22:28:49 1883 Мелкая правка: ' $z2_i=min\limits_j (z[j] +' -
ru2 Russian Edvard 2015-12-25 20:01:20 789 (опубликовано)
ru1 Russian Edvard 2015-12-25 17:59:53 3576 Первая редакция (сохранено в черновиках)