Codeforces Round 1067 (Div. 2)

7 problems from Codeforces Round 1067 (Div. 2) (contest 2158), difficulty 800-3000. 2/7 solutions verified against sample I/O.

7 items

Codeforces Round 1067 (Div. 2)

Div. 2 | 7 problems | 2/7 verified | Difficulty 800-3000 | 10m 44s

# Problem Rating Tags Accepted Time ✓
A Suspension 800 constructive-algorithms, greedy, math 23,377 1m 11s ✓
B Split 1200 constructive-algorithms, greedy, math 13,932 1m 47s
C Annoying Game 1400 dp, games, greedy 11,047 1m 25s ✓
D Palindrome Flipping 2000 brute-force, constructive-algorithms, graphs 3,279 1m 44s
E Sink 2600 data-structures, divide-and-conquer, dsu 624 1m 34s
F1 Distinct GCDs (Easy Version) 2600 constructive-algorithms, graphs, math 403 1m 35s
F2 Distinct GCDs (Hard Version) 3000 combinatorics, constructive-algorithms, graphs 247 1m 28s
Practice › Codeforces Solutions › Codeforces Round 1067 (Div. 2) ›

CF 2158F2 - Distinct GCDs (Hard Version)

We are asked to construct a sequence of length $n$, where each element is a positive integer up to $10^{18}$, with a very specific constraint on neighboring pairs. For every adjacent pair $(ai, a{i+1})$, we compute its gcd.
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CF 2158F1 - Distinct GCDs (Easy Version)

We are asked to construct a sequence of length $n$, where each element is a large positive integer, and the goal is to control the structure of greatest common divisors between consecutive elements. For every adjacent pair $(ai, a{i+1})$, we compute $gcd(ai, a{i+1})$.
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CF 2158E - Sink

We are given a 2D grid of size $n times m$, where each cell contains a positive integer. We can construct "holes" in cells. A cell is considered a sink either if it has a hole, or if it is adjacent (sharing a side) to another sink with a smaller or equal value.
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CF 2158D - Palindrome Flipping

We are given two binary strings of equal length. Think of them as two rows of switches, where each position is either off or on. The task is to transform the first row into the second by repeatedly choosing a segment and flipping all bits in that segment.
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CF 2158B - Split

We are given an array of length $2n$. We must split its elements into two subsequences $p$ and $q$, each containing exactly $n$ elements. Order inside a subsequence does not matter, only the multiset of chosen values matters.
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CF 2158C - Annoying Game

We are given an array $a$ and another array $b$ of the same length. Two players alternate turns for exactly $k$ moves. On each move, the current player picks an index and either adds or subtracts the corresponding value $bi$ from $ai$.
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CF 2158A - Suspension

We are given a football match with a fixed number of players, and a sequence of disciplinary actions in the form of yellow and red cards. Each yellow card contributes toward a potential suspension, and each red card immediately suspends a player.
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