Codeforces Round 978 (Div. 2)

Solutions for Codeforces Round 978 (Div. 2) (contest 2022). 3/7 problems verified against sample I/O. Difficulty range: 800-2700.

7 items

Codeforces Round 978 (Div. 2)

Type: Div. 2 | Problems: 7 | Verified: 3/7 | Rating range: 800-2700 | Time: 14m 17s

Problem Name Rating Tags Solve Time Verified
A Bus to P\u00e9njamo 800 constructive-algorithms, greedy, implementation 2m 18s ✓
B Kar Salesman 1300 binary-search, greedy, math 1m 53s ✓
C Gerrymandering 1800 dp, implementation 1m 38s ✓
D1 Asesino (Easy Version) 1900 binary-search, brute-force, constructive-algorithms 1m 30s ✗
D2 Asesino (Hard Version) 2700 constructive-algorithms, dp, interactive 1m 59s ✗
E1 Billetes MX (Easy Version) 2500 2-sat, binary-search, combinatorics 2m 6s ✗
E2 Billetes MX (Hard Version) 2600 binary-search, combinatorics, data-structures 2m 53s ✗
Practice › Codeforces Solutions › Codeforces Round 978 (Div. 2) ›

CF 2022E2 - Billetes MX (Hard Version)

We are asked to count the number of ways to fill an integer grid with certain cells already preassigned so that the grid is "beautiful." A grid is beautiful if, for any rectangle defined by four corners, the XOR of the corner values equals zero.
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Practice › Codeforces Solutions › Codeforces Round 978 (Div. 2) ›

CF 2022E1 - Billetes MX (Easy Version)

We are given a partially specified n × m grid. Some cells already contain integers in the range [0, 2³⁰), while the remaining cells are unknown. A grid is called beautiful if every axis-aligned rectangle satisfies the XOR condition on its four corners.
codeforces competitive-programming 2-sat binary-search combinatorics constructive-algorithms dfs-and-similar dsu graphs Jun 8, 2026
Practice › Codeforces Solutions › Codeforces Round 978 (Div. 2) ›

CF 2022D2 - Asesino (Hard Version)

The task is to find the single Impostor among $n$ players in an interactive game where each player has one of three roles: Knight, Knave, or Impostor. Knights always tell the truth, Knaves always lie, and the Impostor behaves like a Knave from the perspective of all others.
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Practice › Codeforces Solutions › Codeforces Round 978 (Div. 2) ›

CF 2022D1 - Asesino (Easy Version)

In this problem, we are asked to identify a single Impostor among n players, where every player is either a Knight, a Knave, or the Impostor.
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Practice › Codeforces Solutions › Codeforces Round 978 (Div. 2) ›

CF 2022A - Bus to Pénjamo

Each bus row contains exactly two seats. We have several families, and family i contains ai people. A person is happy in one of two situations. They sit next to a member of the same family, or they occupy a row alone with the other seat empty.
codeforces competitive-programming constructive-algorithms greedy implementation math Jun 8, 2026
Practice › Codeforces Solutions › Codeforces Round 978 (Div. 2) ›

CF 2022B - Kar Salesman

Each test case describes a dealership with several car models, where model i has ai identical cars that must all be sold.
codeforces competitive-programming binary-search greedy math Jun 8, 2026
Practice › Codeforces Solutions › Codeforces Round 978 (Div. 2) ›

CF 2022C - Gerrymandering

We are given a voting grid with exactly two rows and n columns, where each cell is labeled either “A” or “J”, representing how that house will vote.
codeforces competitive-programming dp implementation Jun 8, 2026