OCPC 2023, Oleksandr Kulkov Contest 3

13 problems from OCPC 2023, Oleksandr Kulkov Contest 3 (contest 104234), difficulty -. 13/13 solutions verified against sample I/O.

13 items

OCPC 2023, Oleksandr Kulkov Contest 3

Special | 13 problems | 13/13 verified | Difficulty - | 12m 15s

# Problem Rating Tags Accepted Time ✓
A Square Sum 54s ✓
B Super Meat Bros 1m 20s ✓
C Testing Subjects Usually Die 58s ✓
D Triterminant 56s ✓
E Garbage Disposal 53s ✓
F Palindromic Polynomial 47s ✓
G Palindromic Differences 1m 14s ✓
H Graph Isomorphism 49s ✓
I DAG Generation 1m 9s ✓
J Persian Casino 48s ✓
K Determinant, or...? 49s ✓
L Directed Vertex Cacti 47s ✓
M Siteswap 51s ✓
Practice › Codeforces Solutions › OCPC 2023, Oleksandr Kulkov Contest 3 ›

CF 104234M - Siteswap

We are given a sequence that describes a repeating juggling pattern over discrete beats. On each beat, either a throw happens with a specified delay, or nothing happens.
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CF 104234L - Directed Vertex Cacti

We are asked to count how many directed graphs can be formed on n labeled vertices under two structural restrictions, together with a global edge count constraint.
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CF 104234K - Determinant, or...?

We are given an array of length $2^n$, and from it we construct a $2^n times 2^n$ matrix. The rows and columns are indexed from $0$ to $2^n - 1$, and the entry at position $(i, j)$ is defined as $a{i , So each matrix entry does not depend on two independent values of the array…
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CF 104234J - Persian Casino

We are simulating a constrained gambling process that behaves less like independent betting and more like a controlled state machine with limited “time travel” resets. Prince starts with a single coin and must go through exactly n betting rounds.
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CF 104234I - DAG Generation

We are looking at a randomized procedure that constructs a directed acyclic graph by processing vertices one by one. At any moment there is a set of already inserted vertices, and a set of remaining vertices.
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CF 104234G - Palindromic Differences

We are given an array of numbers, and we are allowed to reorder it arbitrarily. For each chosen ordering, we build a second array consisting of consecutive differences between adjacent elements.
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CF 104234H - Graph Isomorphism

We are given an undirected simple graph on $n$ vertices. From this graph, we conceptually generate all graphs that can be obtained by relabeling vertices in every possible way. Two relabelings that produce different edge sets count as different graphs.
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CF 104234F - Palindromic Polynomial

We are given several independent test cases. In each one, a hidden polynomial is known to have a symmetric coefficient pattern, meaning the coefficient list reads the same from left to right and from right to left.
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CF 104234E - Garbage Disposal

We are given a continuous block of integers from L to R. Think of these numbers as both “positions” and “items” at the same time. For every number i in this segment, we must assign it a distinct number yᵢ from the same segment, forming a permutation of the interval.
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CF 104234D - Triterminant

We are given a binary sequence where each element is either +1 or −1. From this sequence we build, for every prefix length k, a determinant of a special k by k matrix.
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CF 104234B - Super Meat Bros

We are building two independent story sequences, one for Meatio and one for Meatigi. Each sequence is formed by concatenating story arcs.
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CF 104234C - Testing Subjects Usually Die

We are repeatedly trying to identify a hidden number between 1 and n. The hidden number is not chosen uniformly: each value i has a given weight pi, and the actual probability of being the correct answer is proportional to these weights.
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CF 104234A - Square Sum

We are given a modulus $m$, and then a list of values $z1, z2, dots, zn$. For each query value $zi$, we want to count how many ordered pairs $(x, y)$ with $0 le x, y < m$ satisfy the congruence $$x^2 + y^2 equiv zi pmod m.
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