Codeforces Round 997 (Div. 2)

7 problems from Codeforces Round 997 (Div. 2) (contest 2056), difficulty 800-3000. 1/7 solutions verified against sample I/O.

7 items

Codeforces Round 997 (Div. 2)

Div. 2 | 7 problems | 1/7 verified | Difficulty 800-3000 | 14m 23s

# Problem Rating Tags Accepted Time ✓
A Shape Perimeter 800 constructive-algorithms, math 26,780 1m 14s ✓
B Find the Permutation 1300 brute-force, dfs-and-similar, graphs 17,917 3m 24s
C Palindromic Subsequences 1200 brute-force, constructive-algorithms, math 19,431 2m 11s
D Unique Median 2200 binary-search, brute-force, combinatorics 3,665 2m 3s
E Nested Segments 2500 combinatorics, dfs-and-similar, dp 1,049 1m 54s
F1 Xor of Median (Easy Version) 2700 bitmasks, brute-force, combinatorics 447 1m 53s
F2 Xor of Median (Hard Version) 3000 bitmasks, brute-force, combinatorics 354 1m 44s
Practice › Codeforces Solutions › Codeforces Round 997 (Div. 2) ›

CF 2056F1 - Xor of Median (Easy Version)

We are asked to work with sequences of integers of length $n$, where each element lies between 0 and $m-1$. A sequence is considered good if the counts of numbers follow a strict non-decreasing property: whenever two numbers $i < j$ both appear in the sequence, the number of…
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CF 2056F2 - Xor of Median (Hard Version)

We are asked to consider sequences of length $n$, where each element is an integer between $0$ and $m-1$. A sequence is deemed "good" if the counts of the elements are non-decreasing with respect to their values: for any pair of numbers $i < j$ that both appear in the sequence…
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CF 2056E - Nested Segments

We are given a set of integer segments over the range [1, n]. Each segment is a closed interval [l, r]. The initial set of segments, S, is "good", meaning that for any two distinct segments in the set, either they do not overlap at all, or one is fully contained in the other.
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CF 2056B - Find the Permutation

We are given an undirected graph whose structure is secretly generated from a hidden permutation of the vertices.
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CF 2056D - Unique Median

We are asked to count subarrays of a given array where the median is uniquely defined. In practice, this means a subarray is good if, after sorting, the middle element (or the two middle elements, if the length is even) are equal.
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CF 2056C - Palindromic Subsequences

We are asked to construct an integer sequence of length $n$ where each element lies between $1$ and $n$, and the sequence has the property that the number of longest palindromic subsequences exceeds $n$.
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CF 2056A - Shape Perimeter

We are given a square stamp of size $m times m$ placed on an infinite grid. We repeatedly move this stamp up and right, and each time we place a full copy of the square on the paper. Each placement paints all unit cells inside that square.
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