Codeforces Beta Round 80 (Div. 1 Only)

Solutions for Codeforces Beta Round 80 (Div. 1 Only) (contest 103). 3/5 problems verified against sample I/O. Difficulty range: 1100-2900.

5 items

Codeforces Beta Round 80 (Div. 1 Only)

Type: Div. 1 | Problems: 5 | Verified: 3/5 | Rating range: 1100-2900 | Time: 10m 20s

Problem Name Rating Tags Solve Time Verified
A Testing Pants for Sadness 1100 greedy, implementation, math 1m 39s ✓
B Cthulhu 1500 dfs-and-similar, dsu, graphs 1m 43s ✓
C Russian Roulette 1900 constructive-algorithms, greedy 2m ✓
D Time to Raid Cowavans 2100 brute-force, data-structures, sortings 1m 48s ✗
E Buying Sets 2900 flows, graph-matchings 3m 10s ✗
Practice › Codeforces Solutions › Codeforces Beta Round 80 (Div. 1 Only) ›

CF 103A - Testing Pants for Sadness

The test contains several questions that must be answered in order. Each question has multiple answer choices, and exactly one of them is correct. Vaganych does not know any correct answers in advance, but after making a mistake he remembers which options were wrong.
codeforces competitive-programming greedy implementation math May 28, 2026
Practice › Codeforces Solutions › Codeforces Beta Round 80 (Div. 1 Only) ›

CF 103B - Cthulhu

We are given an undirected graph and need to decide whether it matches a very specific structure. The graph should contain exactly one simple cycle, and every other vertex must belong to a tree attached to some vertex on that cycle.
codeforces competitive-programming dfs-and-similar dsu graphs May 28, 2026
Practice › Codeforces Solutions › Codeforces Beta Round 80 (Div. 1 Only) ›

CF 103C - Russian Roulette

The cylinder has n slots arranged in a circle, and exactly k of them contain bullets. Before the game starts, the cylinder is rotated uniformly at random, so every cyclic shift is equally likely. After the rotation, Sasha shoots first.
codeforces competitive-programming constructive-algorithms greedy May 28, 2026
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CF 103D - Time to Raid Cowavans

We have an array of cow weights. For every query (a, b), we repeatedly take positions a, a + b, a + 2b, ... until the index exceeds n, and we must output the sum of all visited values.
codeforces competitive-programming brute-force data-structures sortings May 28, 2026
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CF 103E - Buying Sets

We are given several sets of integers, each with an associated cost. We may choose any collection of these sets, including the empty collection. Let the number of chosen sets be $k$, and let the union of all chosen sets contain $u$ distinct integers.
codeforces competitive-programming flows graph-matchings May 28, 2026