Codeforces Round 912 (Div. 2)

Solutions for Codeforces Round 912 (Div. 2) (contest 1903). 2/7 problems verified against sample I/O. Difficulty range: 800-2500.

7 items

Codeforces Round 912 (Div. 2)

Type: Div. 2 | Problems: 7 | Verified: 2/7 | Rating range: 800-2500 | Time: 14m 2s

Problem	Name	Rating	Tags	Solve Time	Verified
A	Halloumi Boxes	800	brute-force, greedy, sortings	2m 22s	✗
B	StORage room	1200	bitmasks, brute-force, constructive-algorithms	1m 53s	✗
C	Theofanis' Nightmare	1400	constructive-algorithms, greedy	1m 40s	✓
D1	Maximum And Queries (easy version)	1700	binary-search, bitmasks, brute-force	2m 15s	✗
D2	Maximum And Queries (hard version)	2500	bitmasks, divide-and-conquer, dp	1m 50s	✗
E	Geo Game	2000	greedy, interactive, math	2m 14s	✗
F	Babysitting	2500	2-sat, binary-search, data-structures	1m 48s	✓

Practice › Codeforces Solutions › Codeforces Round 912 (Div. 2) ›

CF 1903F - Babysitting

We are asked to install cameras in a house modeled as an undirected graph so that every edge has at least one endpoint with a camera. This is equivalent to finding a vertex cover of the graph: a set of nodes such that every edge touches at least one node from the set.

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CF 1903E - Geo Game

We are asked to reason about a two-player game on a 2D plane. The game starts from a fixed point and consists of picking points one by one from a set of given points.

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CF 1903D1 - Maximum And Queries (easy version)

We are given an array of integers and a budget of operations, where each operation allows increasing a single element by 1.

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CF 1903D2 - Maximum And Queries (hard version)

We are given an array of integers. We are allowed to increase individual elements, one increment at a time, and each increment costs one unit of budget.

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CF 1903A - Halloumi Boxes

The problem gives us a line of boxes, each labeled with a number, and Theofanis wants to arrange them in non-decreasing order. The twist is that he cannot swap arbitrary boxes or perform standard sorting operations.

Practice › Codeforces Solutions › Codeforces Round 912 (Div. 2) ›

CF 1903B - StORage room

We are given a symmetric matrix that is claimed to come from a hidden array through a bitwise construction rule. The hidden array has $n$ non-negative integers, each less than $2^{30}$.

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CF 1903C - Theofanis' Nightmare

We are given an array of integers, and our task is to split it into contiguous, non-empty subarrays. Each subarray contributes to a weighted sum called the Cypriot value, which is calculated as the sum over all subarrays of the subarray sum multiplied by its 1-based index in…