Codeforces Round 874 (Div. 3)

Solutions for Codeforces Round 874 (Div. 3) (contest 1833). 2/7 problems verified against sample I/O. Difficulty range: 800-1800.

7 items

Codeforces Round 874 (Div. 3)

Type: Div. 3 | Problems: 7 | Verified: 2/7 | Rating range: 800-1800 | Time: 13m 52s

Problem	Name	Rating	Tags	Solve Time	Verified
A	Musical Puzzle	800	implementation, strings	1m 31s	✓
B	Restore the Weather	900	greedy, sortings	4m 8s	✗
C	Vlad Building Beautiful Array	800	greedy, math	1m 49s	✗
D	Flipper	1400	brute-force, constructive-algorithms, greedy	1m 46s	✗
E	Round Dance	1600	dfs-and-similar, dsu, graphs	2m	✗
F	Ira and Flamenco	1700	combinatorics, constructive-algorithms, data-structures	1m 13s	✓
G	Ksyusha and Chinchilla	1800	constructive-algorithms, dfs-and-similar, dp	1m 25s	✗

Practice › Codeforces Solutions › Codeforces Round 874 (Div. 3) ›

CF 1833G - Ksyusha and Chinchilla

We are given a tree, and we are allowed to remove edges. After removing some edges, the remaining connected components must each consist of exactly three vertices, and each such component must itself still be a tree.

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CF 1833F - Ira and Flamenco

We are given an array of student skill levels, and we want to count how many ways we can choose exactly m students to form a group under two simultaneous constraints.

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CF 1833B - Restore the Weather

We are given two arrays of the same length. One array represents predicted temperatures for each day, and the other contains the actual temperatures, but the actual values are shuffled and their ordering is lost.

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CF 1833E - Round Dance

We are given a group of people at a festival, each of whom remembers exactly one neighbor in a round dance. Each dance is a closed cycle where every participant has exactly two neighbors, but we only know one neighbor per person.

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CF 1833D - Flipper

We are given a permutation of integers from 1 to $n$. Our goal is to perform a two-part operation exactly once to produce the lexicographically largest permutation possible.

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CF 1833C - Vlad Building Beautiful Array

We are given an array of positive integers, and the task is to construct a new array of the same length where all elements are positive and have the same parity, either all odd or all even.

Practice › Codeforces Solutions › Codeforces Round 874 (Div. 3) ›

CF 1833A - Musical Puzzle

We are given a target melody, which is just a string over the alphabet {a, b, c, d, e, f, g}. Vlad cannot directly build this string in arbitrary chunks. Instead, he can only record pieces of length exactly two characters, like "ab" or "gg".