Codeforces Round 767 (Div. 1)

Solutions for Codeforces Round 767 (Div. 1) (contest 1628). 0/7 problems verified against sample I/O. Difficulty range: 1400-3500.

7 items

Codeforces Round 767 (Div. 1)

Type: Div. 1 | Problems: 7 | Verified: 0/7 | Rating range: 1400-3500 | Time: 20m 13s

Problem	Name	Rating	Tags	Solve Time	Verified
A	Meximum Array	1400	binary-search, constructive-algorithms, greedy	1m 44s	✗
B	Peculiar Movie Preferences	1700	greedy, strings	1m 44s	✗
C	Grid Xor	2300	constructive-algorithms, greedy, implementation	7m 41s	✗
D1	Game on Sum (Easy Version)	2100	combinatorics, dp, games	2m 18s	✗
D2	Game on Sum (Hard Version)	2400	combinatorics, dp, games	1m 33s	✗
E	Groceries in Meteor Town	3100	binary-search, data-structures, dsu	1m 59s	✗
F	Spaceship Crisis Management	3500	binary-search, data-structures, geometry	3m 14s	✗

Practice › Codeforces Solutions › Codeforces Round 767 (Div. 1) ›

CF 1628C - Grid Xor

We are given an even-sized $n times n$ grid of integers that was stolen, and instead of the original numbers, we only know the XOR of the neighbors of each cell. Our task is to compute the XOR of all the original numbers in the grid.

Practice › Codeforces Solutions › Codeforces Round 767 (Div. 1) ›

CF 1628F - Spaceship Crisis Management

We are asked to determine, for multiple starting positions in space, whether there exists a straight-line trajectory to the target position at the origin, potentially interacting with stationary obstacles represented as line segments.

Practice › Codeforces Solutions › Codeforces Round 767 (Div. 1) ›

CF 1628E - Groceries in Meteor Town

We are given a tree where each edge carries a weight that represents how dangerous it is to traverse during a meteor storm. Alongside this structure, we maintain a dynamic set of “active” nodes, which represent buildings with open grocery stores. Initially, no store is open.

Practice › Codeforces Solutions › Codeforces Round 767 (Div. 1) ›

CF 1628D1 - Game on Sum (Easy Version)

We are asked to analyze a two-player game between Alice and Bob. The game lasts for n turns, and in each turn Alice chooses a number between 0 and k.

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CF 1628D2 - Game on Sum (Hard Version)

Alice and Bob play a game of alternating choices over n turns. On each turn, Alice picks a number between 0 and k. Bob then decides whether to add or subtract that number from the total score, with the constraint that he must add at least m times over the entire game.

Practice › Codeforces Solutions › Codeforces Round 767 (Div. 1) ›

CF 1628A - Meximum Array

We are given an array of non-negative integers and we are allowed to repeatedly cut off a prefix of the current array. For each cut, we compute the MEX of that prefix and append it to a new array.

Practice › Codeforces Solutions › Codeforces Round 767 (Div. 1) ›

CF 1628B - Peculiar Movie Preferences

We are given a sequence of short strings, each representing a scene in a movie. From these scenes we are allowed to pick a subsequence, meaning we keep the original order but may skip some scenes. If we concatenate the chosen scenes, we obtain a single string.