OCPC Fall 2023 - Day 1: Jeroen Op de Beek Contest

11 problems from OCPC Fall 2023 - Day 1: Jeroen Op de Beek Contest (contest 105214), difficulty -. 11/11 solutions verified against sample I/O.

11 items

OCPC Fall 2023 - Day 1: Jeroen Op de Beek Contest

Special | 11 problems | 11/11 verified | Difficulty - | 10m 30s

#	Problem	Time	✓
A	Anton's ABCD	52s	✓
B	Beer Circuits	1m 9s	✓
C	Curly Palindromes	1m 30s	✓
D	Division 3 Polyglot	1m 10s	✓
E	Enumerating Substrings	46s	✓
F	Football in Osijek	1m 13s	✓
G	Graffiti	1m 1s	✓
H	Huge Oil Platform	44s	✓
I	Isomorphic Delight	41s	✓
J	Jumbled Primes	44s	✓
K	King's Dinner	40s	✓

Practice › Codeforces Solutions › OCPC Fall 2023 - Day 1: Jeroen Op de Beek Contest ›

CF 105214A - Anton's ABCD

We are given a string made only of the letters A, B, C, and D. The only operation we are allowed to perform is selecting a contiguous block of four characters that forms a cyclic rotation of the pattern ABCD and then rotating that block by one position left or right.

Practice › Codeforces Solutions › OCPC Fall 2023 - Day 1: Jeroen Op de Beek Contest ›

CF 105214B - Beer Circuits

We are given a set of points in the plane, each representing a pub. We want to choose an ordered circuit of at least 3 and at most k distinct pubs, visit them in that order, and return to the starting pub, forming a cycle.

Practice › Codeforces Solutions › OCPC Fall 2023 - Day 1: Jeroen Op de Beek Contest ›

CF 105214C - Curly Palindromes

We are given up to 100 distinct labeled points in the plane. We must construct a sequence of these points, where repetition is allowed, subject to three constraints.

Practice › Codeforces Solutions › OCPC Fall 2023 - Day 1: Jeroen Op de Beek Contest ›

CF 105214K - King's Dinner

We are given a square floor of size $n times n$, where each cell can either remain empty or be covered by a domino-shaped table that occupies exactly two neighboring cells.

Practice › Codeforces Solutions › OCPC Fall 2023 - Day 1: Jeroen Op de Beek Contest ›

CF 105214J - Jumbled Primes

We are given a hidden permutation of the integers from 1 to 100. At position i there is a value p[i], but we never see it directly. The only information we can extract is by choosing two positions a and b and asking for gcd(p[a], p[b]).

Practice › Codeforces Solutions › OCPC Fall 2023 - Day 1: Jeroen Op de Beek Contest ›

CF 105214I - Isomorphic Delight

We are asked to construct a simple undirected graph on n labeled vertices, or decide that it cannot be done, with a very strong structural constraint: the graph must be asymmetric. Asymmetric here means there is no non-trivial relabeling of vertices that preserves adjacency.

Practice › Codeforces Solutions › OCPC Fall 2023 - Day 1: Jeroen Op de Beek Contest ›

CF 105214H - Huge Oil Platform

We are given a set of weighted points in the plane. Each point represents a potential oil extraction site, located at integer coordinates, and each carries a profit value.

Practice › Codeforces Solutions › OCPC Fall 2023 - Day 1: Jeroen Op de Beek Contest ›

CF 105214G - Graffiti

We are given a tree with $n$ nodes, and we are free to assign a lowercase letter to each node. After labeling, every simple path in the tree becomes a sequence of letters, read along the unique path between its endpoints.

Practice › Codeforces Solutions › OCPC Fall 2023 - Day 1: Jeroen Op de Beek Contest ›

CF 105214F - Football in Osijek

We are given a directed graph on $n$ vertices where every vertex has exactly one outgoing edge, defined by the array $a$. From each player $i$, there is a mandatory requirement that if $i$ is selected, then $ai$ must also be selected.

Practice › Codeforces Solutions › OCPC Fall 2023 - Day 1: Jeroen Op de Beek Contest ›

CF 105214E - Enumerating Substrings

We are working with two layers of combinatorics. First, there is a text string $S$ of length $n$ over an alphabet of size $k$, where $k$ can be extremely large, up to $10^9$, so we should think of characters as abstract labels rather than concrete letters.

Practice › Codeforces Solutions › OCPC Fall 2023 - Day 1: Jeroen Op de Beek Contest ›

CF 105214D - Division 3 Polyglot

We are asked to construct a single input file that is simultaneously valid for two different Codeforces problems, each with its own input format and interpretation rules, and force both correct solutions to produce the same numeric output, namely a given integer $x$.