Codeforces Round 604 (Div. 1)

6 problems from Codeforces Round 604 (Div. 1) (contest 1264), difficulty 1500-3500. 2/6 solutions verified against sample I/O.

7 items

Codeforces Round 604 (Div. 1)

Div. 1 | 6 problems | 2/6 verified | Difficulty 1500-3500 | 12m 26s

# Problem Rating Tags Accepted Time ✓
A Beautiful Regional Contest 1500 greedy, implementation 10,440 1m 27s
B Beautiful Sequence 1900 brute-force, constructive-algorithms, greedy 6,046 2m 35s
C Beautiful Mirrors with queries 2400 data-structures, probabilities 1,322 3m 40s
D1 Beautiful Bracket Sequence (easy version) 2600 combinatorics, dp, probabilities 1,525 1m 21s ✓
D2 Beautiful Bracket Sequence (hard version) 2900 combinatorics, probabilities 1,315 1m 39s
F Beautiful Fibonacci Problem 3500 constructive-algorithms, number-theory 1,097 1m 44s ✓
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CF 1264C - Beautiful Mirrors with queries

Each mirror acts like a probabilistic “step” in a process that either advances forward or forces a restart. Creatnx begins at mirror 1 and repeatedly asks mirrors in increasing index order. When mirror i responds positively, the process moves to i + 1 on the next day.
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CF 1264D2 - Beautiful Bracket Sequence (hard version)

We are given a string made of three types of characters: left brackets, right brackets, and question marks. Each question mark can independently become either type of bracket, so the input describes a large family of fully specified bracket strings.
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CF 1264A - Beautiful Regional Contest

We are given a non-increasing array of scores representing contest results. Our task is to split the top portion of this ranking into three contiguous groups: gold, silver, and bronze. Everyone after the bronze group receives no medal.
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CF 1264D1 - Beautiful Bracket Sequence (easy version)

We are given a string of length up to 2000, consisting of three kinds of characters: opening brackets, closing brackets, and wildcards.
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CF 1264F - Beautiful Fibonacci Problem

We are given a small arithmetic sequence of positive integers: $a, a+d, a+2d, dots, a+(n-1)d$. The goal is to find another arithmetic sequence $b, b+e, b+2e, dots, b+(n-1)e$ such that the last 18 digits of the corresponding Fibonacci numbers contain the original numbers as…
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CF 1264B - Beautiful Sequence

There is not enough information to diagnose the bug or provide a corrected solution. The sample with expected output appears to belong to a string construction problem, but you have not provided: - the problem statement, - the original Python solution, - or even the name of…
codeforces competitive-programming brute-force constructive-algorithms greedy Jun 11, 2026