Codeforces Round 984 (Div. 3)

7 problems from Codeforces Round 984 (Div. 3) (contest 2036), difficulty 800-2200. 4/7 solutions verified against sample I/O.

7 items

Codeforces Round 984 (Div. 3)

Div. 3 | 7 problems | 4/7 verified | Difficulty 800-2200 | 12m 48s

# Problem Rating Tags Accepted Time ✓
A Quintomania 800 implementation 40,685 1m 1s ✓
B Startup 800 greedy, sortings 29,738 2m 4s
C Anya and 1100 1100 brute-force, implementation 22,192 1m 5s ✓
D I Love 1543 1300 brute-force, implementation, matrices 15,983 3m 4s ✓
E Reverse the Rivers 1600 binary-search, constructive-algorithms, data-structures 9,537 2m 4s ✓
F XORificator 3000 1900 bitmasks, dp, number-theory 5,259 2m
G Library of Magic 2200 binary-search, constructive-algorithms, divide-and-conquer 1,669 1m 30s
Practice › Codeforces Solutions › Codeforces Round 984 (Div. 3) ›

CF 2036G - Library of Magic

We are dealing with a very large universe of book types, from 1 up to n where n can be as large as 10^18. Every type normally appears exactly twice in a hidden collection.
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CF 2036D - I Love 1543

The input describes several rectangular grids of digits. Each grid is split conceptually into concentric “rings” or layers, starting from the outer border and moving inward. Every layer forms a closed cycle if you walk along its border clockwise.
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CF 2036F - XORificator 3000

The failure you show is not enough to diagnose the algorithm itself. Let's trace what happened: The input contains 5 test cases: The program produced only: instead of: This means the code successfully processed the first test case and then terminated before handling the…
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CF 2036E - Reverse the Rivers

We are given a world with n countries, each divided into k regions, where each region has an initial water value a[i][j]. The sages have built channels so that water in a region flows downstream through countries in the same region index.
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CF 2036B - Startup

The failure you show is not enough to diagnose the algorithm itself. Let's trace what happened: The input contains 5 test cases: The program produced only: instead of: This means the code successfully processed the first test case and then terminated before handling the…
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CF 2036C - Anya and 1100

We are given a binary string that changes over time. Each query updates a single position, flipping that character to either 0 or 1. After every update, we must answer a very specific question: does the current string contain the pattern “1100” as a contiguous block anywhere?
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CF 2036A - Quintomania

A melody here is just a short sequence of integer pitches. Each pitch is an integer between 0 and 127, and what matters is not the absolute values but the differences between neighboring notes.
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