Codeforces Beta Round 27 (Codeforces format, Div. 2)

Solutions for Codeforces Beta Round 27 (Codeforces format, Div. 2) (contest 27). 4/5 problems verified against sample I/O. Difficulty range: 1200-2200.

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Codeforces Beta Round 27 (Codeforces format, Div. 2)

Type: Div. 2 | Problems: 5 | Verified: 4/5 | Rating range: 1200-2200 | Time: 6m 38s

Problem Name Rating Tags Solve Time Verified
A Next Test 1200 implementation, sortings 1m 13s ✓
B Tournament 1300 bitmasks, brute-force, dfs-and-similar 1m 3s ✓
C Unordered Subsequence 1900 constructive-algorithms, greedy 1m 18s ✗
D Ring Road 2 2200 2-sat, dfs-and-similar, dsu 1m 30s ✓
E Number With The Given Amount Of Divisors 2000 brute-force, dp, number-theory 1m 34s ✓
Practice › Codeforces Solutions › Codeforces Beta Round 27 (Codeforces format, Div. 2) ›

CF 27A - Next Test

We are given the indices of tests that already exist in the system. Every index is a positive integer, and all indices are distinct. The task is to find the smallest positive integer that does not appear in the list.
codeforces competitive-programming implementation sortings May 28, 2026
Practice › Codeforces Solutions › Codeforces Beta Round 27 (Codeforces format, Div. 2) ›

CF 27B - Tournament

We are asked to reconstruct the missing result of a round-robin tournament. There are _n_ participants, and every participant plays against every other participant exactly once.
codeforces competitive-programming bitmasks brute-force dfs-and-similar greedy May 28, 2026
Practice › Codeforces Solutions › Codeforces Beta Round 27 (Codeforces format, Div. 2) ›

CF 27C - Unordered Subsequence

We are given a sequence of integers, and we are asked to extract the shortest subsequence that is _not ordered_. A sequence is considered ordered if it is either entirely non-decreasing or entirely non-increasing.
codeforces competitive-programming constructive-algorithms greedy May 28, 2026
Practice › Codeforces Solutions › Codeforces Beta Round 27 (Codeforces format, Div. 2) ›

CF 27D - Ring Road 2

We have a cycle of n cities arranged on a ring. Every pair of consecutive cities is already connected by the outer ring road, and city n is also connected back to city 1.
codeforces competitive-programming 2-sat dfs-and-similar dsu graphs May 28, 2026
Practice › Codeforces Solutions › Codeforces Beta Round 27 (Codeforces format, Div. 2) ›

CF 27E - Number With The Given Amount Of Divisors

We are given a single integer n, and we need to construct the smallest positive integer whose number of divisors is exactly n.
codeforces competitive-programming brute-force dp number-theory May 28, 2026