brain

We are given a connected undirected graph with n vertices and exactly n − 1 edges, so the structure is a tree. The number of vertices is odd, which implies the number of edges is even, since a tree always has n − 1 edges.

We are given a large multiset of integers generated by a recurrence. Conceptually, think of it as a box containing many balls, each labeled with a value.

We are given a permutation $P$ of the numbers from $1$ to $n$. We want to count how many permutations $Q$ of the same set satisfy a local constraint that links neighboring elements of $Q$ through the mapping defined by $P$.

An $(s,t)$-combination in dual form is a strictly decreasing sequence $b_s > b_{s-1} > \cdots > b_1 \ge 0,$ where ${b_1,\dots,b_s}$ are exactly the positions of the $0$’s in a binary string of length...

We are given a sequence of integers and a threshold value $k$. From this sequence, we want to select a subsequence (preserving original indices) such that every pair of chosen values is “close” in value: the absolute difference between any two chosen elements must be at most…

We are given a fraction $frac{p}{q}$ and need to determine whether it can be represented in a very specific symmetric form involving two positive integers $a$ and $b$. The task is to either construct such a pair or report that it is impossible.

We are given a very small grid, at most 8 by 8, where each cell is either fixed as 0, fixed as 1, or flexible and marked as 2. Every 2 can independently become either 0 or 1, so the final matrix is chosen by deciding all those replacements.

Each item gives a function indexed by $i$, defined by two parameters $ki$ and $ai$. The function is periodic in $x$, and its shape is determined by a transformed tangent expression involving $sec(x-ai)$.

We are given a long digit string and a collection of small digit patterns, each pattern carrying a weight. For any string $S$, we define its value as the sum over all patterns of how many times each pattern appears as a substring inside $S$, multiplied by that pattern’s…

We are maintaining a sequence of numbers that represents the current “power level” of a collection of eggs. Each egg has an initial value, and over time we repeatedly apply multiplicative updates on subsegments or ask for the sum of a subsegment. There are two operations.

We are given a rectangular grid of numbers. For each cell, we look at all values that lie either in the same row or in the same column as that cell, including the cell itself. Among all those values, we check whether the current cell’s value is the smallest.

We are given a small number of fractions, each represented by a pair of integers $p$ and $q$. The unusual operation allowed is to delete digits from the decimal representations of both numbers, but only in pairs: whenever a digit appears in both numbers, we may choose…

We are given an array of positive integers. The goal is to reduce every value to zero using a sequence of operations. In one operation, we choose a list of indices $B1, B2, dots, Bm$.

We are given a weighted undirected graph representing a campus. Moving along an edge of length $w$ takes time proportional to how you travel: walking always costs $w / t$, while cycling costs $w / r$, with $r ge t$, so cycling is faster.

Each query gives two integer sequences and a parameter $k$. The operation allowed is to pick a starting position $a$ and swap two consecutive blocks of length $k$: the segment $S[a..a+k-1]$ is exchanged with $S[a+k..a+2k-1]$.

Working

We are given an array of non-negative integers that is supposed to represent values generated by a hidden modulus process. There exists an unknown positive integer $M$, and the array is expected to match the sequence formed by taking powers of two and reducing them modulo $M$.

We are given a sequence of strings, and we are allowed to pick any subset of them while preserving their original order. After choosing a subset, we concatenate the selected strings into a single long string.

We are given a rooted tree where only the leaves matter for the final goal. Every leaf already has a required final color, while internal nodes have no target color at all. Initially, nothing is painted.

Connection interrupted. Waiting for the complete answer

We are given a complete directed graph on $n$ vertices, but most edges are not explicitly listed. For every ordered pair $(u, v)$, there is always an edge from $u$ to $v$.

We are given a graph with $n$ vertices where every pair of vertices is connected by an edge. This is not a standard complete graph with arbitrary weights: most edges follow a simple rule based on vertex weights, while a smaller subset of edges comes with explicitly given costs…

We are given a list of files arranged in a vertical list, initially sorted by their current filenames. Each file has an original name from a range and a target new name from another range.

We are given a collection of combat units, each described by an attack value and a health value. One unit is chosen as the initial “active” unit.

Working

We are given a reference string $S$, and then many query strings $Ti$. For each query string, we imagine building an infinite string by repeating $Ti$ forever.

We are given an undirected graph where each node carries a non-negative integer value. The graph structure tells us which nodes can interact, and the values evolve through an operation applied along any chosen path.

We are given a sequence of length $n$, but it is not an arbitrary sequence. It is a permutation of $1$ through $n$, so every value is distinct and each value appears exactly once.

We are given a set of Pokémon, each fully described by the same structured data used in the main series games: level, base stats, individual values, effort values, and four moves with fixed power and type.

We are given a rectangular building on a 2D plane, aligned with the coordinate axes. Each canteen is represented as a single point. For every canteen, we want to compute its shortest Euclidean distance to any point on the rectangle, including its interior boundary and corners.

Let $(a_{ij})$ be an $m\times n$ contingency table with row sums $r_i=\sum_{j=1}^n a_{ij}, \quad 1\le i\le m,$ and column sums $c_j=\sum_{i=1}^m a_{ij}, \quad 1\le j\le n,$ with $\sum_{i=1}^m r_i=\sum...

We are given an array of length $2^n$, where the initial values are fixed as $ai = i$. So we start with a perfectly ordered sequence of integers from $0$ to $2^n - 1$. The process then repeatedly reduces the array size in $n$ rounds.

Each query gives a single integer status code produced when a user tries to access a service. For every such code, the system must decide whether the request succeeds or fails.

We are given a rooted tree. Each node has a notion of depth (distance from the root), and we are interested in answering queries about properties of nodes in subtrees, typically something like maximum depth, height contribution, or aggregated values over all nodes in a subtree.

I don’t have the actual problem statement for Codeforces 103449G - Xor Plains, so I can’t safely write a correct editorial without risking inventing details.

The problem statement for Codeforces 103449F - àPaPdnarG is missing from your prompt. Without the actual definition of the input, output, and constraints, I can’t correctly reconstruct the problem or write a valid editorial.

The statement for Codeforces 103449E - Rubik String is missing from your prompt, so I don’t have the actual rules, input format, or what is being computed.

I can’t reliably write a correct editorial for Codeforces 103449D - Updating Inversions without the actual problem statement.

We are dealing with numbers written in base 5, so every number is treated as a sequence of digits where each digit is between 0 and 4.

The problem statement is missing, so I can’t reliably derive the solution or write a correct editorial for Codeforces 103449A.

I can’t reliably reconstruct the exact statement of Codeforces 103449C “Find Set” from the available public index alone, and there isn’t enough structured problem text exposed to safely infer the intended task without risking a wrong editorial.

I can’t write a correct Codeforces editorial for 103451J - Number because the actual problem statement (input/output definition and constraints) is missing from your prompt.

Let $m_0,\dots,m_s$ and $t$ be fixed nonnegative integers, and let $C(m_0,\dots,m_s;t)$ denote the set of all bounded compositions r_0+\cdots+r_s=t,\qquad 0\le r_j\le m_j\ \ (0\le j\le s).

We are given an array of non-negative integers, and a recursive operation that repeatedly “expands” it into a new value. At the base level, when the level is zero, the value is simply the sum of all elements in the array.

I can’t write a correct Codeforces editorial for this problem as-is because the actual statement is missing. Right now we only have the title “Krosh and bit operations”, but no description of: what the input represents, what operations are performed, or what needs to be…

We are given a single integer n, and two players alternate moves on it. On each move, the player looks at the current number and either reduces it by one or halves it with floor division.

We are working with permutations of the numbers from 1 to n, chosen uniformly at random. For any interval [l, r], we compute a value by starting from p[l] and repeatedly applying modulo with the next elements: we replace the current value x by x mod p[i] as we extend the…

The problem statement for Codeforces 103451F - Krosh and series sum 2 is missing from your prompt, so there’s no way to reliably reconstruct the task, constraints, or required computation.

The problem statement is missing from your prompt, so I can’t reliably reconstruct the intended task for Codeforces 103451E.

I can write the full editorial, but I’m missing the actual problem statement for Codeforces 103451D - Krosh and powers of two.

I can’t write a correct editorial for Codeforces 103451C - Krosh and paths without the actual problem statement.

I’m missing the actual problem statement for Codeforces 103451A - Game, so I can’t responsibly write a correct editorial yet.

I can’t write a correct editorial yet because the actual problem statement for “Codeforces 103455A - Fundraising the Game” isn’t included.

Let $m_0,\dots,m_s$ and $t$ be fixed nonnegative integers, and let $C(m_0,\dots,m_s;t)$ denote the set of all bounded compositions r_0+\cdots+r_s=t,\qquad 0\le r_j\le m_j\ \ (0\le j\le s).

I’m missing the actual statement for Codeforces 103455I “Exiting the Maze”, so I can’t reliably reconstruct the problem or derive a correct solution.

I can’t write a correct editorial for this yet because the actual problem statement is missing from your prompt. Right now I only see the title, but no description of the maze rules, input format, or what “escape” means in this variant.

The problem statement is missing, so there isn’t enough information to write a correct editorial. “Marbles Pt.

I can’t reliably write a correct editorial for Codeforces 103455F - Maze Escape Pt. I without the actual problem statement. Right now the statement section is empty, and this problem ID doesn’t give enough signal to safely reconstruct the intended graph/maze mechanics.

I cannot produce a correct editorial yet because the actual problem statement for Codeforces 103455E - Ppopgi is not provided, and I also cannot reliably infer it from metadata alone without risking hallucinating a completely different problem.

We are missing one crucial ingredient here: the actual statement of Codeforces 103455D “Tug of War” is not available in the prompt. Without the formal rules of the process, any attempt to write a correct editorial would risk inventing a problem that does not match the judge.

We are given a timeline of a simple traffic-light game and a set of competitors who try to reach a finish line before the light becomes permanently red.

I can’t reliably produce a correct editorial yet because the actual problem statement for Codeforces 103455B - Prize Change is not available from the context you provided, and it is not a standard publicly indexed Codeforces problem in the usual problemset form I can…

The statement for “Codeforces 103456K - Marbles Pt. II” isn’t actually included here, and without it there’s no reliable way to reconstruct the intended solution, constraints, or even the underlying task type.

The statement for Codeforces 103456J - Dastardly Dalgona is missing from your prompt, so there’s no way to reconstruct the actual task, constraints, or required algorithm.

The statement section is empty, so there isn’t enough information to reconstruct what Codeforces 103456I - Exiting the Maze is actually asking.

I can write the full editorial in your required style, but I’m missing the actual problem content. Right now the statement section is empty, so I don’t know: - what the maze looks like (grid, graph, dynamic changes, etc.

I don’t have the actual problem statement for Codeforces 103456G - Marbles Pt. I, and without it I can’t write a correct editorial. Anything I write now would be guesswork, and for a Codeforces-style solution walkthrough that would be actively misleading.

Let $m_0,\dots,m_s$ and $t$ be fixed nonnegative integers, and let $C(m_0,\dots,m_s;t)$ denote the set of all bounded compositions r_0+\cdots+r_s=t,\qquad 0\le r_j\le m_j\ \ (0\le j\le s).

I’m missing the actual problem statement for “Codeforces 103456F - Maze Escape Pt. I”, so I can’t responsibly write a correct editorial yet.

I can’t write a correct editorial for “Codeforces 103456E - Ppopgi” because the actual problem statement is missing from your message.

The problem describes a one-dimensional track of positions that must be traversed from left to right. Each position behaves like a traffic light that alternates between two states, red and green, in a repeating cycle.

I’m missing the actual problem statement for Codeforces 103456D - Tug of War, so I can’t write a correct editorial yet. Please paste the full problem statement (or at least the description, constraints, and samples).

I’m missing the actual problem statement for Codeforces 103457H - “Еще более защищенная тюрьма”, and without it I can’t reliably reconstruct the model, constraints, or intended solution path.

I can’t produce a correct Codeforces-style editorial without the actual problem statement. Right now the prompt only contains the title “Долгое путешествие (Long Journey)”, but the key parts are missing: what the input represents, what operations are…

I can’t write a correct editorial for this without the actual problem statement. Right now I only have the title (“Симбиоты внутри”), but no definition of the input, output, or rules of the problem.

I can’t reliably write a correct editorial for “Codeforces 103457E - Secure Prison” because the problem statement is missing from your prompt.

The problem statement is missing from your prompt (both the “Problem Statement”, “Input”, and “Output” sections are empty). Without that, I can’t reconstruct the task or produce a correct editorial.

I can’t reliably write a correct editorial for Codeforces 103457F - “Размещение симбиотов” without the actual problem statement.

The problem statement section is empty, so there isn’t enough information to derive the algorithm, constraints, or even what the task is asking for. For a Codeforces editorial, the actual input/output definition is essential.

I can’t write a correct editorial for this yet because the actual problem content for Codeforces 103457D - “Спрятать заложницу” is missing from your prompt.

The problem statement for “Codeforces 103457C - В поисках Венома” is missing from your message, so I don’t have the actual task definition, input/output format, or constraints.

I can’t produce a correct editorial yet because the actual problem statement is missing from your prompt. Right now I only see: - Problem title: “Активная подготовка к битве” - No description of the input, output, or rules Without that, any…

The problem statement section is empty, so there’s not enough information to derive an algorithm, constraints, or even what the input/output represent.

I don’t have the actual problem statement for Codeforces 103458I - “Палиндромная шифровка” in the prompt you provided, and I can’t reliably reconstruct it from the title alone without risking inventing details.

I need to be honest first: the full statement of Codeforces 103458H - Компонентная химия is not reliably available in a clean form from standard sources, and the snippets that exist are partial and inconsistent across archives.

I can’t reliably write a correct editorial for this yet because the actual problem statement is missing. Right now I only have the title “Взрывоопасная лестница” (“Explosive staircase”), but no description of what the stairs do, what constitutes a…

I’m missing the actual problem statement for Codeforces 103458F - “Поезда в Зауне”, so I can’t safely reconstruct the solution or write a correct editorial yet.

I’m missing the actual problem content for “103458E - Джинкс и лагерь миротворцев” (the statement, constraints, and I/O format are empty in your message).

I can’t reliably write a correct editorial for this without the actual problem statement. Right now the prompt only includes the title “103458B - Производство Мерцания”, but no description, input/output format, or constraints.

We are missing the actual statement of Codeforces 103458D in the prompt you provided. The problem name “Тренировки миротворцев” (“Peacekeepers’ training”) exists, but the task description (what is given, what must be computed, and constraints) is…

Let $r_s,\dots,r_0$ satisfy t = r_s + \cdots + r_1 + r_0,\qquad 0 \le r_j \le m_j \quad (s \ge j \ge 0).

The process being modeled is a turn-based elimination game played on a circular gun cylinder with a fixed number of chambers. Some chambers contain bullets and others are empty.

I can’t reliably reconstruct the problem from “Codeforces 103458A - Цепная реакция” with the information available here, and the web results are not giving a consistent statement for that exact index.

We are standing on an infinite grid starting at the origin. Each test gives a target coordinate, and we must construct a walk that eventually reaches that point. The movement rule is unusual: time is split into phases.

We are given a set of rectangular boxes placed somewhere on a large 2D plane. Each box is described by four corner points in counterclockwise order, so every obstacle is a convex quadrilateral with arbitrary orientation, not necessarily axis-aligned.

We are given an array whose length is exactly a power of two, specifically $2^k$, where $k$ can be as large as 20. Each operation takes the current array and throws away exactly one half of it, either the left half or the right half, and keeps the other half unchanged.

We are given an integer array and a special value $k$. The process is dynamic: as long as the array still contains at least one element equal to $k$, we repeatedly apply an operation that decreases every positive element of the array by one.

We are interacting with a hidden string of length at most 100. The string uses exactly two distinct lowercase letters, but we are not told which ones. Our only way to learn about it is by asking whether a chosen pattern appears as a contiguous substring of the hidden string.

We are given a tree, meaning a connected acyclic graph on $n$ nodes with $n-1$ edges. The task is to count how many distinct subgraphs of a specific shape appear inside this tree.

We are given a binary string where some positions are already fixed as 0 or 1, while others are unknown and marked with ?. We are allowed to replace each ? with either 0 or 1, producing a fully binary string.