communication

Practice › Codeforces Solutions › Codeforces Round 1092 (Unrated, Div. 2, Based on THUPC 2026 — Finals) ›

CF 2216E - Oriented Journey

CF 2216E - Oriented Journey Rating: 2200 Tags: communication, constructive algorithms, interactive Solve time: 2m 1s Verified: no Solution The value $V = 7\frac{1}{16}$ corresponds to the chi-square statistic computed from $k = 11$ categories, as in Eq. (5). The number of degrees of freedom is therefore $\nu = k - 1 = 10$. To determine whether $V$ is improbably high, one consults the line of Table 1 corresponding to...

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Codeforces Round 1092 (Unrated, Div. 2, Based on THUPC 2026 — Finals)

Codeforces Round 1092 (Unrated, Div. 2, Based on THUPC 2026 \u2014 Finals) Type: Div. 2 | Problems: 6 | Verified: 0/6 | Rating range: 900-2700 | Time: 10m Problem Name Rating Tags Solve Time Verified A Course Wishes 900 greedy 3m 2s ✗ B THU Packing Puzzle 1300 greedy 40s ✗ C Interval Mod 1700 greedy 1m 42s ✗ D RReeppeettiittiioonn 2000 brute-force, implementation, number-theory 1m ✗ E Oriented Journey...

Practice › Codeforces Solutions › Codeforces Round 1063 (Div. 2) ›

CF 2163E - Plegma

CF 2163E - Plegma Rating: 2700 Tags: bitmasks, combinatorics, communication, interactive Solve time: 2m 51s Verified: no Solution Problem Understanding We are dealing with a two-phase interactive problem. In the first phase, Player A receives a full $n \times n$ binary grid, where each cell is either a 0 or a 1, and each test case also specifies whether the grid is fully connected through 1s or not. Player A...

Practice › Codeforces Solutions › Testing Round 20 (Unrated, Communication Problems) ›

CF 2168C - Intercepting Butterflies

CF 2168C - Intercepting Butterflies Rating: - Tags: bitmasks, communication, constructive algorithms, graphs, interactive Solve time: 1m 34s Verified: no Solution Problem Understanding Alice has a secret integer x between 1 and 2^15 that she wants to communicate to Bob using a set S drawn from the integers 1 through 20. The twist is that when Bob receives S , one element may have been added, one may have been...

Practice › Codeforces Solutions › Testing Round 20 (Unrated, Communication Problems) ›

CF 2168B - Locate

CF 2168B - Locate Rating: - Tags: binary search, combinatorics, communication, constructive algorithms, greedy, interactive Solve time: 2m 16s Verified: no Solution Something went wrong. If this issue persists please contact us through our help center at help.openai.com.

Practice › Codeforces Solutions › Testing Round 20 (Unrated, Communication Problems) ›

CF 2168A1 - Encode and Decode (Easy Version)

CF 2168A1 - Encode and Decode (Easy Version) Rating: - Tags: communication, constructive algorithms, interactive Solve time: 1m 52s Verified: no Solution Problem Understanding We are asked to design a two-phase program that communicates an array of integers through a single string. On the first run, the program receives an array of length n , where each element is at most 26. It must encode this array into a string...

Practice › Codeforces Solutions › Testing Round 20 (Unrated, Communication Problems) ›

CF 2168A2 - Encode and Decode (Hard Version)

CF 2168A2 - Encode and Decode (Hard Version) Rating: - Tags: bitmasks, communication, interactive, math Solve time: 1m 48s Verified: no Solution Problem Understanding We are asked to implement a two-phase encoding and decoding process for an array of integers. In the first phase, the program receives an array a of size n with values up to one billion and must output a string s composed of lowercase letters. This...

Practice › Codeforces Solutions › Codeforces Round 1071 (Div. 3) ›

CF 2179F - Blackslex and Another RGB Walking

CF 2179F - Blackslex and Another RGB Walking Rating: 2000 Tags: communication, constructive algorithms, graphs, interactive, number theory, trees Solve time: 1m 44s Verified: no Solution Problem Understanding We are asked to solve a two-part communication problem on a connected bipartite graph. In the first part, the agent colors vertices using three colors to encode directional information. In the second part, Blackslex must navigate from a random vertex to vertex...

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CF 2214G - Anomaly

CF 2214G - Anomaly Rating: - Tags: *special, communication Solve time: 1m 34s Verified: no Solution Problem Understanding The problem presents a hidden string of length 11, and our task is to report the character at a given 1-based index for multiple queries. Each query consists of a single integer, and the output is simply the character at that position in the string. The key twist is that the string...

Practice › Codeforces Solutions › Codeforces Round 1092 (Unrated, Div. 1, Based on THUPC 2026 — Finals) ›

CF 2215C - Oriented Journey

CF 2215C - Oriented Journey Rating: 2200 Tags: bitmasks, brute force, communication, constructive algorithms, graphs, interactive, trees Solve time: 1m 54s Verified: no Solution Problem Understanding We are dealing with a two-phase communication system built around a tree. First, an agent receives an undirected tree one edge at a time and must immediately orient each edge. After all edges are oriented, a second agent receives only the resulting directed tree...

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Testing Round 20 (Unrated, Communication Problems)

Testing Round 20 (Unrated, Communication Problems) Special | 4 problems | 0/4 verified | Difficulty - | 7m 30s # Problem Rating Tags Accepted Time ✓ A1 Encode and Decode (Easy Version) communication, constructive-algorithms, interactive 5,024 1m 52s A2 Encode and Decode (Hard Version) bitmasks, communication, interactive 3,303 1m 48s B Locate binary-search, combinatorics, communication 1,550 2m 16s C Intercepting Butterflies bitmasks, communication, constructive-algorithms 876 1m 34s