ABBYY Cup 2.0 - Hard

18 problems from ABBYY Cup 2.0 - Hard (contest 178), difficulty 1000-2500. 10/18 solutions verified against sample I/O.

18 items

ABBYY Cup 2.0 - Hard

Special | 18 problems | 10/18 verified | Difficulty 1000-2500 | 29m 40s

# Problem Rating Tags Accepted Time ✓
A1 Educational Game 1000 1,835 1m 53s ✓
A2 Educational Game 1000 greedy 1,856 1m 33s
A3 Educational Game 1100 greedy 1,608 1m 58s ✓
B1 Greedy Merchants 1600 865 1m 31s ✓
B2 Greedy Merchants 1600 770 1m 58s ✓
B3 Greedy Merchants 1800 1,524 1m 51s ✓
C1 Smart Beaver and Resolving Collisions 1600 586 1m 37s ✓
C2 Smart Beaver and Resolving Collisions 1900 339 1m 34s
C3 Smart Beaver and Resolving Collisions 2000 358 1m 13s ✓
D1 Magic Squares 1500 735 58s ✓
D2 Magic Squares 1900 326 1m 53s
D3 Magic Squares 2100 271 1m 49s ✓
E1 The Beaver's Problem - 2 1900 314 1m 43s
E2 The Beaver's Problem - 2 2000 241 1m 44s
E3 The Beaver's Problem - 2 2300 214 1m 49s
F1 Representative Sampling 1800 459 1m 38s
F2 Representative Sampling 2200 dp, sortings, strings 384 1m 31s ✓
F3 Representative Sampling 2500 484 1m 27s
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CF 178F3 - Representative Sampling

We are given a multiset of strings, each string representing a protein. From this collection, we must choose exactly $k$ strings and assign a score to the chosen subset. The score is defined over all unordered pairs of chosen strings.
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CF 178F2 - Representative Sampling

We are given a collection of n protein strings, and we are asked to select exactly k of them such that the sum of the longest common prefixes (LCPs) between every pair in the selected subset is maximized. Each protein is a non-empty string of lowercase letters.
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CF 178F1 - Representative Sampling

We are given a multiset of strings, each string representing a protein sequence. From these strings, we must choose exactly k of them.
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CF 178E3 - The Beaver's Problem - 2

We are given a square, monochrome image represented as an $n times n$ matrix, where each element is either 0 (white background) or 1 (black foreground). Within this image are several distinct geometric shapes, each either a square or a circle.
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CF 178E2 - The Beaver's Problem - 2

We are given a large binary grid representing a noisy black-and-white image. The white background contains several black connected regions, and each such region is guaranteed to be either a square or a circle, possibly rotated in any orientation.
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CF 178E1 - The Beaver's Problem - 2

We are given a large binary image represented as an $n times n$ grid, where each cell is either white or black. The black cells form several disconnected shapes, and each shape is guaranteed to be either a circle or a square, possibly rotated arbitrarily.
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CF 178D3 - Magic Squares

The task is to take a set of $n^2$ integers and arrange them into an $n times n$ matrix such that the sum of every row, every column, and both diagonals is equal. This sum is called the magic constant $s$.
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CF 178D2 - Magic Squares

We are asked to construct an $n times n$ magic square using a given multiset of $n^2$ integers. A magic square has the property that the sums of all rows, all columns, and both diagonals are equal.
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CF 178D1 - Magic Squares

We are asked to arrange a given set of $n^2$ integers into an $n times n$ matrix so that it forms a magic square. A magic square is defined as a matrix where the sum of every row, every column, and the two main diagonals is the same value $s$.
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CF 178C3 - Smart Beaver and Resolving Collisions

We are maintaining a hash table with a fixed number of slots, where each slot can hold at most one object. Each object has a unique identifier and a preferred starting position given by its hash value. When inserting an object, we first try its hash position.
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CF 178C2 - Smart Beaver and Resolving Collisions

We are simulating a hash table that supports inserting and deleting items, but insertion is not direct. Each item has a preferred starting position given by its hash value, and if that slot is occupied, the table probes forward in fixed jumps of size m modulo h until it finds…
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CF 178C1 - Smart Beaver and Resolving Collisions

We are simulating a hash table where each object is assigned a preferred position given by its hash value, but collisions are resolved using a fixed step size. When an object is inserted, we first try its hash position.
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CF 178B3 - Greedy Merchants

We are given an undirected connected graph where cities are nodes and roads are edges. For each merchant, we are also given a pair of cities: a warehouse city and a shop city. The merchant needs to ship goods from the warehouse to the shop using any path in the graph.
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CF 178B2 - Greedy Merchants

We are given a connected undirected graph of cities linked by roads. Each merchant chooses two cities, one as a source (warehouse) and one as a destination (shop).
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CF 178B1 - Greedy Merchants

We are given an undirected connected graph representing cities and roads. Each road can be removed, and this may or may not break connectivity between two specific cities. Alongside the graph, we are given multiple merchants.
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CF 178A2 - Educational Game

We are given a sequence of non-negative integers representing some kind of “counters” along a line, indexed from 1 to n. The task is to reduce the first k elements of the sequence to zero, for every possible prefix length k (from 1 to n-1).
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CF 178A1 - Educational Game

We have an array of non-negative integers. In one move, we choose an index i with a[i] 0, decrease a[i] by one, and increase some position i + 2t by one. The destination index must have the same parity as i, because the distance moved is always even.
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CF 178A3 - Educational Game

We have an array of non-negative integers. In one move, we pick an index i with a[i] 0, decrease a[i] by 1, and increase some position j by 1, where j - i must be even and j = i. The parity restriction is the core of the problem.
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