Codeforces Beta Round 90

5 problems from Codeforces Beta Round 90 (contest 119), difficulty 800-2500. 4/5 solutions verified against sample I/O.

5 items

Codeforces Beta Round 90

Beta | 5 problems | 4/5 verified | Difficulty 800-2500 | 9m 34s

# Problem Rating Tags Accepted Time ✓
A Epic Game 800 implementation 29,580 1m 29s ✓
B Before Exam 1900 constructive-algorithms, implementation, sortings 1,137 2m 2s ✓
C Education Reform 2000 dp 1,044 2m 59s
D String Transformation 2500 hashing, strings 625 1m 34s ✓
E Alternative Reality 2400 geometry 123 1m 30s ✓
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CF 119A - Epic Game

We are asked to simulate a turn-based game between two players, Simon and Antisimon, who each have a fixed integer, a and b respectively. There is a heap of n stones.
codeforces competitive-programming implementation May 28, 2026
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CF 119B - Before Exam

We have n theorems, and each theorem has a proficiency value assigned to it. The exam contains exactly k different cards. Every card contains exactly floor(n / k) distinct theorems, and no theorem appears in more than one card.
codeforces competitive-programming constructive-algorithms implementation sortings May 28, 2026
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CF 119C - Education Reform

We have up to 50 subjects. Each subject has three properties. The interval $[ai, bi]$ describes how many homework exercises this subject may assign. We are free to choose any value inside that interval. The value $ci$ is the subject complexity.
codeforces competitive-programming dp May 28, 2026
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CF 119D - String Transformation

We are given two strings, a and b, of equal length up to one million characters. The task is to find indices i and j in a such that if we perform a specific transformation, we get b.
codeforces competitive-programming hashing strings May 28, 2026
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CF 119E - Alternative Reality

We are given a three-dimensional space containing $n$ fixed points, representing the centers of energy spheres. There are $m$ levels, and in each level the player starts at a plane passing through the origin.
codeforces competitive-programming geometry May 28, 2026