Codeforces Round 963 (Div. 2)

Solutions for Codeforces Round 963 (Div. 2) (contest 1993). 2/7 problems verified against sample I/O. Difficulty range: 800-2800.

7 items

Codeforces Round 963 (Div. 2)

Type: Div. 2 | Problems: 7 | Verified: 2/7 | Rating range: 800-2800 | Time: 18m 21s

Problem Name Rating Tags Solve Time Verified
A Question Marks 800 greedy, implementation 2m 29s ✓
B Parity and Sum 1100 constructive-algorithms, greedy 2m 10s ✓
C Light Switches 1400 implementation, math 2m 51s ✗
D Med-imize 2200 binary-search, dp, greedy 2m 37s ✗
E Xor-Grid Problem 2700 bitmasks, constructive-algorithms, dp 3m 26s ✗
F1 Dyn-scripted Robot (Easy Version) 2400 brute-force, chinese-remainder-theorem, constructive-algorithms 1m 50s ✗
F2 Dyn-scripted Robot (Hard Version) 2800 chinese-remainder-theorem, math, number-theory 2m 58s ✗
Practice › Codeforces Solutions › Codeforces Round 963 (Div. 2) ›

CF 1993F2 - Dyn-scripted Robot (Hard Version)

We are asked to simulate the movement of a robot inside a bounded rectangle, starting at the bottom-left corner. The robot follows a script of movements, each of which is one of the four cardinal directions.
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CF 1993E - Xor-Grid Problem

We are given a small matrix of integers, and the operations we can perform are unusual. For any row, we can replace every element with the XOR of the corresponding column. For any column, we can replace every element with the XOR of the corresponding row.
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CF 1993D - Med-imize

We are given an array of integers and a parameter $k$. We can repeatedly remove any contiguous subarray of length exactly $k$ from the array, shrinking it. Once the array's length is no longer greater than $k$, we stop.
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CF 1993F1 - Dyn-scripted Robot (Easy Version)

We are simulating a deterministic robot moving on a grid that is bounded by a rectangle. The robot starts at the origin and repeatedly executes a fixed instruction string consisting of unit moves in four directions.
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CF 1993C - Light Switches

The problem involves an apartment with multiple rooms, each starting with its light turned off. Each room gets a chip installed at a distinct time, and each chip toggles the light in its room on and off periodically, with a period k minutes.
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CF 1993A - Question Marks

We are given a multiple-choice test with $4n$ questions, where each of the four options 'A', 'B', 'C', 'D' is correct exactly $n$ times. Tim answers the questions but may leave some as '?', representing unknown answers.
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CF 1993B - Parity and Sum

We are given an array of positive integers, and we want all elements to share the same parity - either all even or all odd. The only allowed operation is to pick two elements of differing parity and add the larger number to the smaller.
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