brain

We are given a positive integer $X$ written in base $B$ as a sequence of digits. The task is to determine whether there exist two positive integers $Y$ and $Z$ such that: $$X + Y = Z$$ and the base-$B$ representations of $Y$ and $Z$ contain exactly the same multiset of digits.

The problem describes a complete binary tree of tasks. The tree has a given height, and initially only the root task is available. There are p processors. During one unit of time, every processor can complete at most one currently available task.

We maintain an array whose elements are always in the range [-2, 2]. Two kinds of operations appear. An update changes one position to a new value. A query gives a nonzero target sum X. We must determine whether there exists a contiguous subarray whose sum is exactly X.

We have a connected undirected graph with labeled vertices representing water stations. Busy Beaver wants to know how many such graphs have the property that every possible spanning tree contains a station whose degree is at least K.

We are given several test cases. In each test case there are $N$ points on a 2D grid, each representing a beaver starting at integer coordinates. All beavers move simultaneously on an infinite plane.

I can't write a correct editorial for this problem from the statement alone. I was able to retrieve the problem statement, but not an official editorial or accepted-solution discussion, and the key part of the solution is nontrivial: after modeling the notes as a DAG whose…

We are given a string made only from the characters M, I, and T. An operation can change a substring MIT into TIM or the other way around. The goal is to perform any number of operations and make the number of contiguous occurrences of MITIT as large as possible.

I can't write a correct editorial for Codeforces 106249C "Quantum Beaver" from the information available to me. The contest page I could access only exposes other problems from the gym and does not include the full statement of problem C. Please provide one of the following: 1.

The problem models a complete binary tree of height h. The root task is available at the beginning. In each second, we have p processors, and each processor can complete one currently available task. When a task is completed, its children become available for future seconds.

I can’t write a correct editorial yet because the actual problem statement is missing. “Codeforces 1062474 - Robot Charging” isn’t enough on its own to reconstruct the task reliably, and anything I guess here would turn into a made-up solution, which defeats the purpose…

We are given two moments on a 24-hour digital clock, inclusive. Every clock reading is displayed as HH:MM, where hours use two digits from 00 to 23 and minutes use two digits from 00 to 59.

The problem describes a shop that wants to choose one pack size a. Every customer wants to buy some amount of cans between l and r. A customer first takes as many full packs of size a as possible.

I can absolutely write that editorial in the format you want, but I’m missing the actual problem statement for Codeforces 1062472 - Sum of Divisors.

Codeforces 106242C: Trees and Flowers (flower)

I can’t produce a correct editorial yet because the actual statement of Codeforces 106242I - Another Construction Problem (construct) is not available in the prompt, and it is not identifiable from standard archives or the search results.

Got it. Please send the full Codeforces problem statement (or link/text + constraints), and I’ll write a complete competitive programming editorial for it-covering intuition, key observations, solution, complexity, and implementation details.

I’m missing the actual problem statement (the section is blank in your prompt), so I can’t safely reconstruct what Codeforces 106242F - Root Distance Sum (rootsum) is asking.

The task is to combine two sequences indexed by positive integers using a number-theoretic pairing rule based on gcd and lcm.

We are given an array of integers and are allowed to change elements arbitrarily, with each change counting as one operation. The goal is to modify the array so that every contiguous segment of it contains at least one value that appears exactly once inside that segment.

The process described is about a person who starts with a fixed number of socks and wears one pair per day. Each day consumes one pair permanently. On certain days, specifically every fixed interval of days, new socks are added, but they are only available starting the next day.

I can’t reliably write a correct editorial yet because the full problem statement for Codeforces 106242B - Sushibwoah (sushi) is not accessible from the standard archive view, and the snippets available do not contain the actual rules of the task.

We are given an $n times m$ grid of positive numbers. From any chosen starting cell, we repeatedly move exactly $n$ times downward and exactly $m$ times to the right, and because the grid wraps, moving down from the last row brings us back to the first row, and moving right…

I can’t reliably write a correct editorial for “Codeforces 106237H - Planar Triangles” from what you provided, because the actual problem statement (what “planar triangles” means here, what input describes, and what is being counted/optimized) is missing.

Sure. Send me the Codeforces problem statement (or link, title, constraints, and examples), and I’ll write a detailed competitive programming editorial with: - Problem restatement - Key observations - Derivation of the solution - Proof of correctness - Complexity analysis -…

I can’t write a correct editorial yet because the actual statement of Codeforces 106237B - Perfect Substring is not included in your prompt, and it also isn’t reliably recoverable from the identifier alone.

I can write the editorial, but I need the actual problem statement for Codeforces 106237C - Counting Binary Strings (Again) first.

The problem statement is missing from your prompt (the section under Problem Statement is empty), so I don’t have enough information to reconstruct what “Array Transformation” is asking.

Codeforces 106235D: Three Subsegments

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We are given a weighted graph where moving along an edge has a cost, and we care about paths from a fixed start node to a fixed target node. Among all possible walks from start to target, there is a minimum possible total cost, the usual shortest path.

Got it. Please paste the Codeforces problem statement (or link + full text), and I’ll write a full competitive programming editorial for it.

We are simulating a seating system in a cafe where both people and tables are ordered by importance. The key idea is that each person arrives with a fixed time interval during which they occupy a table, and tables cannot host overlapping intervals.

I don’t actually have the statement of Codeforces 106235B - Proof of Incorrectness available, and I can’t reliably reconstruct it from the title alone without risking inventing details.

I can’t reliably write a correct editorial for this problem yet because I don’t have the actual statement content for Codeforces 106233L - “Хакерская задача” available here, and I can’t infer it safely from the title alone.

The process starts with a single integer placed on a board. You are allowed to repeatedly take any number currently on the board, erase it, and replace it with two positive integers whose sum equals the erased value.

We have a sequence of magic marks placed on a plane. The i-th mark has coordinates (xi, yi). A trick chooses a consecutive segment of marks and rotates every mark in that segment around a given point by 90, 180, or 270 degrees clockwise.

I can’t reliably write a correct Codeforces editorial from just the problem code/name here because the actual statement is missing.

I don’t have the actual problem statement for Codeforces 106233H - “Расширение Всадников”, and without it I can’t produce a correct editorial.

The problem is about building a “chain” of substrings taken from a single given string, with a strong nesting constraint. You start with the full string and want to pick several substrings in order from left to right.

I can write the full editorial in that format, but I’m missing the actual problem details. The prompt only gives the title “Codeforces 106233E - Иллюзия XOR-а” and empty sections for the statement/input/output.

I can’t safely write a correct editorial yet because I don’t have the actual statement of Codeforces 106233G - “Вечный двигатель” (Eternal Engine).

We are given a construction that can be viewed as a very thin lattice made from matches. Imagine two horizontal rows of points, each row containing n positions, and matches connect neighboring points horizontally and vertically, forming a standard 2 by n grid of unit squares.

I cannot reliably reconstruct Codeforces 106233A “Не иллюзия обмана” from public problemset sources, and I should not guess the statement or solution.

We have a baker with a limited amount of dough and several types of fillings. A bun of a particular filling consumes some amount of dough and some amount of that filling, and gives a certain profit. The baker can also make plain buns that only consume dough.

The task is about rearranging an array into sorted order, but with a restriction on which swaps are allowed. You are given a sequence of integers, and you are allowed to swap two elements only if at least one of them is a “lucky” number, meaning its decimal representation…

I can’t reliably reconstruct the full statement of Codeforces 106230E - “Колобки против Энигмы” from available metadata alone, and there isn’t enough accessible problem text in the contest archive to avoid guessing.

I can write the full editorial in that format, but I need the actual problem statement or a link to the problem. I could not reliably identify Codeforces 106230A “Гипнотическая мелодия” from the problem ID and title alone, and inventing the algorithm…

I can’t write a correct editorial yet because the actual problem statement for Codeforces 106230B - “Ночная операция” is missing from your message. Right now I don’t know: what the input represents, what operations are allowed, or what needs to be computed.

I can’t write a correct editorial for this yet because the problem statement is missing. Right now I only have the title “Рыбий жир без ГМО”, but no description of the task, input/output format, or constraints.

We are given a line of fields indexed from left to right. On top of this line, there are several preprogrammed spraying routes. Each route is an interval, meaning it fertilizes every field in some contiguous segment $[Li, Ri]$. A query does not ask about all routes.

I can’t reliably reconstruct Codeforces 106224A - Monster Battle from the title alone, and the editorial needs the exact rules to be correct.

Sure. Send me the Codeforces problem statement (or link/text), and I’ll write a detailed competitive programming editorial with: - Problem restatement - Key observations - Intuition behind the solution - Proof of correctness - Algorithm - Complexity analysis - Implementation…

We have several vegetables. Vegetable i needs to be produced in quantity Ai, and producing one unit currently consumes Bi units of water. The total water needed is the sum of Ai Bi over all vegetables.

The setting is a rectangular farm split into an $N times M$ grid. Every cell contains a fruit type represented by an integer, and bees move across the grid using standard four-directional grid steps, always traveling along shortest paths.

I can write the full editorial in that format, but I’m missing the actual problem details for Codeforces 106222B - Secret. The statement fields in the prompt are empty, and I could not reliably identify the problem from the ID alone.

Each person lives at a position on the north bank and works at a position on the south bank. Walking is only possible along a bank, while crossing the river normally requires a boat that takes B time units.

The earlier coordinate idea can be retained only after checking the transformation carefully.

There are two parallel sidewalks, A and B, each containing positions from 1 through n. You start at position 1 on sidewalk A and want to reach position n on sidewalk B. Moving forward by one position along a sidewalk takes one second.

We are given a one-dimensional grid of cells, each cell carrying an integer value that can be positive or negative.

We are given an array a where each position represents a word and its assigned score. For every pair of indices (i, j) with i < j, the problem defines $$text{dist}(i,j)=ai+aj$$ A pair is considered beautiful when the distance exactly matches the difference between their…

We are given several test cases. In each test case, there is a circular classroom with $k$ numbered seats arranged in a cycle from $1$ to $k$. Some of these seats are occupied by $n$ students, and each student $i$ is sitting at a known seat position $ai$.

We are given n words. For each word, we must check whether it is exactly the string "WY". If a word is exactly "WY", we replace it with "Whitney Young" in the output. Every other word must be printed unchanged. The input consists of an integer n, followed by n strings.

I cannot reliably reconstruct the full statement of Codeforces 106189M - Memory Manager from the identifier alone, and the problem content is not available in the context you provided.

including a full proof, implementation details, traced examples, and assert-based tests.

I’m missing a critical piece of information needed to write a correct editorial: the actual statement of Codeforces Gym 106189J is not included in your prompt, and the Gym page is not fully accessible from the available sources.

We are given a rectangular garden placed on an infinite integer grid. The rectangle is axis-aligned and described by its lower-left corner and its width and height. So every integer point inside that rectangle, including the boundary, is a potential planting location.

I can write the editorial, but I don't have the actual statement for Gym/Codeforces 106189K "Factorials". The problem page for Gym 106189K is not publicly accessible through the available sources, and the prompt you provided contains empty sections for the statement, input…

We are given the scoring log of a Tetris player. Each log entry tells us that the player cleared exactly 1, 2, 3, or 4 lines at once, represented by the strings single, double, triple, and tetris. The player starts at level 18.

I can't reliably write a correct editorial for Codeforces 106189G "Card deck" because the actual problem statement is missing from your prompt, and I could not retrieve the Gym problem text from available sources. Please provide one of the following: 1.

We are given a mathematical expression written as a string. It contains non-negative integers, parentheses, and the two binary operators + and -. The structure is already syntactically valid, so every operator sits between two well-formed subexpressions.

We are given an integer sequence and may delete any elements while preserving the order of the remaining ones. The goal is to keep as many elements as possible so that in the resulting subsequence every internal element is a strict peak or a strict valley.

We have a rectangular maze. Empty cells are traversable, cells marked X are blocked. The player starts in the top-left corner and wants to reach the bottom-right corner using four-directional moves. We want to place exactly one additional obstacle into an empty cell.

The game log describes a simplified Tetris scoring session where every action is a line clear event of fixed size: a single row clear, a double, a triple, or a four-line clear.

Igor has n walls. Every wall is exactly 3 meters high, and the i-th wall has width ai. The store sells wallpaper rolls that are also 3 meters high, so height never causes any waste. Each roll covers exactly k meters of width.

I can't write a correct editorial for Codeforces 106180E from the information provided because the actual problem statement, input format, and output format are missing.

We are given a set of intersections connected by directed roads. Each road can be traversed in its intended direction without cost, but if we go against the direction of a road, we must pay a penalty specific to that road.

We are given a sequence that behaves like a list of “records” over time, where each element can be thought of as a score or a value attached to a position. Along with this, we are given a set of allowed exchange operations.

We are missing the actual statement for Codeforces 106180A - “Игра с шариками”. Without the formal rules, input format, and constraints, any editorial would be a guess, and for Codeforces problems even small mismatches in rules completely change the solution.

We start with an array of size $2^n$ where each position initially stores its own index, so position $i$ holds value $i$. The index $i$ is also interpreted as an $n$-bit binary number. The only non-query operations repeatedly apply a transformation based on Gray code blocks.

I don’t have the actual statement for Codeforces 106114C - Arc Path in the prompt, and without it I’d be forced to guess the structure of the problem.

I can’t write a correct Codeforces-style editorial for this yet because the actual problem content is missing. Right now I only have the title “Divisor Transformation”, but no definition of what a transformation is, what the input/output mean, or what constraints apply.

We are given a very simplified cost model of a program that runs a loop many times. Each loop iteration does two kinds of work: a number of computational operations and a number of integer insertions into a data structure.

I cannot responsibly write a correct editorial yet because the problem “Codeforces 106110H - Parallel Checking” is not identifiable from the available statement content.

I can’t write a correct editorial for this yet because the actual problem statement for “Codeforces 106110F - Compromise” isn’t included, and I don’t have enough reliable context to reconstruct it without risking inventing details.

I can’t write a correct editorial for this yet because the actual problem statement is missing. “Codeforces 106110E - Final Rankings” could refer to several different tasks depending on the contest context, and without the description (what the input represents, what…

We are given a collection of independent tasks, each with a processing cost, and three identical machines that can execute these tasks. Each task must be assigned to exactly one machine, and a machine’s load is defined as the sum of processing times of tasks assigned to it.

The task revolves around simulating arithmetic on integers where values can grow beyond the range of standard fixed-width types. You are given a sequence of operations that progressively modifies a single accumulator.

I’m missing the actual statement of Codeforces 106110B (“What to solve next?”). Without the problem description, any editorial would be guesswork, and for Codeforces writeups that quickly leads to incorrect assumptions about the task, constraints, and intended solution.

The problem statement is missing, so there’s no way to correctly reconstruct what Codeforces 106038I - Moscow is asking. Right now I only see the input/output placeholders without any description of the task, constraints, or operations.

Let $c_1,\dots,c_m$ be subcubes of the $n$-cube.

The statement for Codeforces 105950O - The Martian (Problema F: Frodo & Sam) is not actually included in the input you provided. Only the header and empty I/O section are present, so there is no definition of the task, constraints, or required computation.

I’m missing the actual problem statement for 105950M - Movieguessr. The input/output section is empty, so there’s no way to reconstruct what the task is (logic, constraints, or even what is being computed).

Sure - please send me the full problem statement (or a link / screenshot text), and I’ll write a complete Codeforces-style editorial. If you want, you can also tell me: - difficulty rating (if known) - whether you want multiple solutions (e.g.

I can absolutely write that kind of editorial, but I’m missing the only thing that makes it possible: the actual problem statement. Right now you’ve only provided the title and metadata, and “Problema K: Kill Bill Vol.

I can’t write a correct editorial for this yet because the actual problem statement is missing. Right now I only see the title “Las Tortuguitas”, but no description of what the input represents, what operations are performed, or what needs to be computed.

I don’t have the actual problem statement for Codeforces 105950J - John Wick in your message. Right now only the title is present, so there’s no way to reliably reconstruct the task, constraints, or required output.

I can’t reliably write a correct editorial here because the actual problem statement content is missing. Right now I only see the title “Cinematic Hierarchy” with empty input/output sections, so there’s no way to know the task, constraints, or required algorithm.

We are given two integers that describe a hidden pair of numbers. Think of two unknown values $A$ and $B$. We are not given them directly, but instead we are told their sum and the absolute difference between them.

I don’t have the actual statement of Codeforces 105950I - Lost Language in your prompt. What you’ve provided only includes the title and an empty input/output section, so there is no information about what the problem is asking, what operations are allowed, or what…

- identify each justification gap,