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tamnd's digital brain — notes, problems, research

41230 notes

CF 103241M - Shion's Feast

The prompt doesn’t include the actual problem statement for Codeforces 103241M - Shion's Feast, so there’s no way to correctly reconstruct the logic, constraints, or required algorithm.

codeforcescompetitive-programming
CF 103241L - Cooked Fish (Easy Version)

The problem statement for “Codeforces 103241L - Cooked Fish (Easy Version)” is not included in your message, so I don’t have the actual task definition, input format, or constraints needed to write a correct editorial.

codeforcescompetitive-programming
CF 103241K - Necklaces

The problem statement is missing from your prompt, so I don’t have enough information to write a correct editorial.

codeforcescompetitive-programming
CF 103241J - Making Stonks

I cannot reliably produce a correct editorial for “Codeforces 103241J - Making Stonks” because the actual problem statement is not available in the prompt, and the accessible information from Codeforces is inconsistent with that specific index.

codeforcescompetitive-programming
CF 103241I - Chessbot's Lawn

The problem statement for Codeforces 103241I - Chessbot's Lawn is missing from your message, so I can’t reconstruct the intended task or produce a correct editorial.

codeforcescompetitive-programming
CF 103241G - Matching Mispronunciations

I can’t write a correct editorial for “Codeforces 103241G - Matching Mispronunciations” because the actual problem statement, inputs, and outputs are missing.

codeforcescompetitive-programming
CF 103241F - Books

We are given a list of books placed on a shelf. Each book has a one-word lowercase title and a publication year. The task is to reorder the shelf so that books are primarily grouped by the first letter of their title in alphabetical order.

codeforcescompetitive-programming
CF 103241A - P=NP

Let $n=s+t$ and let the ground positions be ${0,1,dots,n-1}$. A configuration is a word $x0x1cdots x{n-1}$ over ${0,1,ast}$ containing exactly $t$ asterisks. The set of all such configurations has size $2^sbinom{s+t}{t}$.

codeforcescompetitive-programming
CF 103241E - Calculating Costs

The problem statement for Codeforces 103241E - Calculating Costs is missing from your prompt. I can’t write a correct editorial without knowing: - what the input represents, - what “costs” are being calculated, - and what operations or constraints define the solution.

codeforcescompetitive-programming
CF 103241D - Abc's (Easy Version)

The problem statement is missing, so I can’t reliably reconstruct what “Codeforces 103241D - Abc’s (Easy Version)” is asking, and I shouldn’t guess because that would lead to a wrong editorial.

codeforcescompetitive-programming
CF 103241C - Lattice Flowers

The problem statement is missing, so I can’t write a correct editorial yet. For a Codeforces editorial, I need at least the full description of what “Lattice Flowers” is asking, including how the input is structured and what needs to be computed.

codeforcescompetitive-programming
CF 103241B - Average

We are given an array of integers, representing values placed in a line. The task is to compute a single number derived from all contiguous segments of this array. For every segment, we compute its arithmetic mean, and then we average those means over all possible segments.

codeforcescompetitive-programming
CF 103256C - Ultimate Huron Sorting

Let $I subseteq mathbb{C}[x1,dots,xs]$ be a homogeneous polynomial ideal. Let $It$ denote the vector space of homogeneous polynomials of degree $t$ contained in $I$. Define $$Nt = dim It,$$ the maximum number of linearly independent degree-$t$ elements of $I$.

codeforcescompetitive-programming
CF 103256G - Special Bracelets

I’m missing the actual problem statement for Codeforces 103256G - Special Bracelets in your prompt, so I can’t reliably reconstruct the task or produce a correct editorial.

codeforcescompetitive-programming
CF 103256I - HuronForces

The problem statement for Codeforces 103256I - HuronForces is not included in your message, so there is no way to reconstruct the task, constraints, or required algorithm reliably.

codeforcescompetitive-programming
CF 103256H - Truth Table

I’m missing the actual problem statement for Codeforces 103256H - Truth Table, and without it I can’t safely reconstruct the intended algorithm or constraints.

codeforcescompetitive-programming
CF 103256F - Moss Growing

I’m missing the actual problem statement for Codeforces 103256F - Moss Growing, and I can’t reconstruct it reliably from the ID alone.

codeforcescompetitive-programming
CF 103256D - Sightseeing with Friends

I can’t write a correct editorial yet because the actual problem statement for “Codeforces 103256D - Sightseeing with Friends” is missing from your prompt. Right now there is no definition of: - what the input represents (graph, array, tree, queries, etc.

codeforcescompetitive-programming
CF 103256B - Huron Jam

I’m missing the actual problem statement for Codeforces 103256B - Huron Jam. Right now there’s no description of the input, output, or rules, so any editorial I write would have to be guessed, which would defeat the purpose of a correct competitive programming explanation.

codeforcescompetitive-programming
CF 103256A - Coffee Bar

The problem statement is missing from the prompt, so there’s no way to correctly reconstruct the intended task or derive an algorithm for “Codeforces 103256A - Coffee Bar” with any reliability.

codeforcescompetitive-programming
CF 103260M - Discrete Logarithm is a Joke

Let $I subseteq mathbb{C}[x1,dots,xs]$ be a homogeneous polynomial ideal. Let $It$ denote the vector space of homogeneous polynomials of degree $t$ contained in $I$. Define $$Nt = dim It,$$ the maximum number of linearly independent degree-$t$ elements of $I$.

codeforcescompetitive-programming
CF 103260L - Extreme Wealth

I’m missing the actual problem content for Codeforces 103260L - Extreme Wealth in your prompt (the statement, input/output description, and constraints are empty).

codeforcescompetitive-programming
CF 103260K - Rectangle Painting

I can’t reliably write a correct Codeforces editorial for “103260K - Rectangle Painting” because the actual problem statement (operations, constraints, and goal) is missing from your prompt.

codeforcescompetitive-programming
CF 103260B - Lockout vs tourist

Let $(a{ij})$ be an $mtimes n$ contingency table with nonnegative integer entries, row sums $ri=sum{j=1}^n a{ij},$ and column sums $cj=sum{i=1}^m a{ij},$ with $sum{i=1}^m ri=sum{j=1}^n cj$.

codeforcescompetitive-programming
TAOCP 7.2.1.3 Exercise 46

Let $n = s + t$ and let $\mathcal{A}$ be a family of $t$-combinations of ${0,1,\dots,n-1}$.

taocpmathematicsalgorithmsvolume-4hard
CF 103260J - Increasing or Decreasing

I don't have enough information to write a correct editorial. The prompt identifies the problem as Codeforces 103260J - Increasing or Decreasing, but the Problem Statement, Input, and Output sections are empty.

codeforcescompetitive-programming
CF 103260I - Trade

The problem statement is missing from your prompt, so there is no way to reconstruct the intended task, constraints, or required output for Codeforces 103260I - Trade.

codeforcescompetitive-programming
CF 103260H - Excluded Min

I can't write an accurate editorial for this problem because the prompt does not include the actual problem statement.

codeforcescompetitive-programming
CF 103260G - Remove the Prime

We are given an array of positive integers. Two players alternate turns, and on each turn a player performs a very specific reduction operation: they pick a prime number $p$ and then choose a contiguous segment of the array such that every number in that segment is divisible…

codeforcescompetitive-programming
CF 103260F - Thanks to MikeMirzayanov

I can't write a correct editorial for this problem because the prompt does not include the actual problem statement.

codeforcescompetitive-programming
CF 103260E - Smol Vertex Cover

The problem statement section is empty, so there isn’t enough information to correctly derive the solution, constraints, or even the core task.

codeforcescompetitive-programming
CF 103260D - Output Limit Exceeded

I can't write a correct editorial because the problem statement is missing. The prompt only provides the title, Codeforces 103260D - Output Limit Exceeded, but the sections for Problem Statement, Input, and Output are empty.

codeforcescompetitive-programming
CF 103260A - Assignment Problem

I don’t have the actual problem statement for Codeforces 103260A - Assignment Problem, and without it there isn’t a reliable way to reconstruct the intended solution or write a correct editorial.

codeforcescompetitive-programming
CF 103260C - Multiple?

I can't write a correct editorial because the actual problem statement is missing. The prompt only includes: - Problem: Codeforces 103260C - Multiple?

codeforcescompetitive-programming
CF 103261K - Interactive Algorithm

Let $(a{ij})$ be an $mtimes n$ contingency table with nonnegative integer entries, row sums $ri=sum{j=1}^n a{ij},$ and column sums $cj=sum{i=1}^m a{ij},$ with $sum{i=1}^m ri=sum{j=1}^n cj$.

codeforcescompetitive-programming
CF 103261L - Not Our Problem

I don't have enough information to write a correct editorial. The prompt identifies the problem as Codeforces 103261L - Not Our Problem, but the actual problem statement, input format, output format, and constraints are missing.

codeforcescompetitive-programming
CF 103261H - Greedy Algorithm

I don’t have the actual statement for Codeforces 103261H - Greedy Algorithm, so I can’t reliably reconstruct the problem or write a correct editorial without risking inventing details.

codeforcescompetitive-programming
CF 103261J - Closest Pair Algorithm

I can't write an editorial for this problem because the prompt does not actually include the problem statement. The fields are empty: - Problem Statement - Input - Output Without knowing what Codeforces 103261J - Closest Pair Algorithm asks for, any algorithm, proof, code…

codeforcescompetitive-programming
CF 103261A - Um_nik's Algorithm

Let $(a{ij})$ be an $mtimes n$ contingency table with nonnegative integer entries, row sums $ri=sum{j=1}^n a{ij},$ and column sums $cj=sum{i=1}^m a{ij},$ with $sum{i=1}^m ri=sum{j=1}^n cj$.

codeforcescompetitive-programming
CF 103261I - Euclid's Algorithm

I don't have enough information to write a correct editorial for this problem. The prompt identifies the problem as Codeforces 103261I - Euclid's Algorithm, but the actual problem statement is empty: - Problem Statement: empty - Input: empty - Output: empty Without the…

codeforcescompetitive-programming
CF 103261E - Binary Search Algorithm

I can't write a correct editorial because the actual problem statement is missing. The prompt only includes: - Problem: Codeforces 103261E - Binary Search Algorithm - Empty Problem Statement - Empty Input - Empty Output Without the statement, it is impossible to determine: -…

codeforcescompetitive-programming
CF 103261G - Petr's Algorithm

I can’t write a correct editorial for CF 103261G - Petr’s Algorithm without the actual problem statement. Right now the input/output and even the core task are missing, and guessing would almost certainly produce a wrong or hallucinated solution (which would defeat the…

codeforcescompetitive-programming
TAOCP 7.2.1.3 Exercise 45

Let $n = s + t$ and let $\mathcal{A}$ be a family of $t$-combinations of ${0,1,\dots,n-1}$.

taocpmathematicsalgorithmsvolume-4hard
CF 103261F - Face Recognition Algorithm

I can’t write a correct editorial for this yet because the actual problem statement for Codeforces 103261F - Face Recognition Algorithm is missing from your prompt.

codeforcescompetitive-programming
CF 103261D - FFT Algorithm

I can’t write a correct editorial for “Codeforces 103261D - FFT Algorithm” because the actual problem statement (what is being computed, what the input represents, and what constraints apply) is missing.

codeforcescompetitive-programming
CF 103261C - StalinSort Algorithm

We are given a sequence of numbers arranged in a fixed order, and we process them from left to right as if we are trying to “stabilize” the sequence.

codeforcescompetitive-programming
CF 103261B - String Algorithm

I can’t reliably write a correct editorial for Codeforces 103261B - String Algorithm without the actual problem statement.

codeforcescompetitive-programming
CF 103262A - Цивилизация

Let $(a{ij})$ be an $mtimes n$ contingency table with nonnegative integer entries, row sums $ri=sum{j=1}^n a{ij},$ and column sums $cj=sum{i=1}^m a{ij},$ with $sum{i=1}^m ri=sum{j=1}^n cj$.

codeforcescompetitive-programming
CF 103262F - Divan любит тыквы

I can’t write a correct editorial for this yet because the actual problem statement is missing. Right now you’ve provided the title and metadata (“Divan любит тыквы”), but there’s no description of the input format, output requirement, or constraints.

codeforcescompetitive-programming
CF 103262E - Проектор

The editorial can’t be written yet because the actual problem statement for “Codeforces 103262E - Проектор” is missing.

codeforcescompetitive-programming
CF 103262D - Магические посохи

I don’t have the actual statement of Codeforces 103262D - “Магические посохи”, so I can’t reliably reconstruct the problem, constraints, or solution without risking inventing details.

codeforcescompetitive-programming
CF 103262C - Счастливые моменты времени

The problem statement is missing, so I don’t have enough information to write a correct editorial. Right now I only know the title “Счастливые моменты времени”, but I don’t know what the input describes, what needs to be computed, or even the…

codeforcescompetitive-programming
CF 103262B - Деревья на аллее

I’m missing the actual problem statement for Codeforces 103262B - “Деревья на аллее”, so I can’t reliably reconstruct the task, constraints, or required solution.

codeforcescompetitive-programming
CF 103264B - Посылки в заморозку

Let $(a{ij})$ be an $mtimes n$ contingency table with nonnegative integer entries, row sums $ri=sum{j=1}^n a{ij},$ and column sums $cj=sum{i=1}^m a{ij},$ with $sum{i=1}^m ri=sum{j=1}^n cj$.

codeforcescompetitive-programming
CF 103264F - Контроль светофоров

The editorial request is missing the actual problem content for “Codeforces 103264F - Контроль светофоров”. Right now there is no statement, input/output description, or constraints, so any solution or reasoning would be guesswork.

codeforcescompetitive-programming
CF 103264E - Преобразование выражения

I don’t have the actual statement of Codeforces 103264E - “Преобразование выражения”, so I can’t reliably reconstruct the problem, constraints, or solution.

codeforcescompetitive-programming
CF 103264D - День города

The problem statement for Codeforces 103264D - “День города” is missing from your prompt, so I can’t reliably write a correct editorial yet. Right now I don’t know what the input represents, what needs to be computed, or what constraints apply.

codeforcescompetitive-programming
CF 103264C - Счастливые дни

I’m missing the actual problem statement for Codeforces 103264C - “Счастливые дни”, so I can’t reliably reconstruct the solution or write a correct editorial.

codeforcescompetitive-programming
CF 103264A - Нейросеть

I can’t reliably write an editorial for “Codeforces 103264A - Нейросеть” without the actual problem statement.

codeforcescompetitive-programming
CF 103265A - Удобно для всех

An $(s,t)$-combination in dual form is a strictly decreasing sequence $bs b{s-1} cdots b1 ge 0,$ where ${b1,dots,bs}$ are exactly the positions of the $0$’s in a binary string of length $n=s+t$. Lexicographic order on tuples $(bs,dots,b1)$ compares entries from left to right.

codeforcescompetitive-programming
TAOCP 7.2.1.3 Exercise 44

Fix an integer $t \ge 1$.

taocpmathematicsalgorithmsvolume-4math-medium
CF 103265F - Спасение любви

The problem statement for “Codeforces 103265F - Спасение любви” is missing from your prompt, so there’s no way to reconstruct the intended task, constraints, or required algorithm.

codeforcescompetitive-programming
CF 103265E - Котлета

I’m missing the actual problem statement for Codeforces 103265E - “Котлета”, so I can’t safely write a correct editorial yet. Right now I only see the title and metadata, but no description of the task, input/output format, or constraints.

codeforcescompetitive-programming
CF 103265D - Максимизируй!

I’m missing the actual statement of Codeforces 103265D (“Максимизируй!”) from your prompt, and I can’t safely reconstruct the problem from the title alone.

codeforcescompetitive-programming
CF 103265C - Бутявочная ферма

I’m missing the actual problem statement for Codeforces 103265C - “Бутявочная ферма”. Right now I only have the title, but no description of: - what the input represents - what needs to be computed - constraints - samples Without that, I can’t reconstruct…

codeforcescompetitive-programming
CF 103265B - Честный дележ

I can’t safely write a correct editorial yet because the actual problem statement is missing. The only thing we have is the title “Честный дележ” (“Fair division”), but Codeforces problem IDs alone don’t uniquely determine the task, and guessing would…

codeforcescompetitive-programming
CF 103269A - Welcome

An $(s,t)$-combination in dual form is a strictly decreasing sequence $bs b{s-1} cdots b1 ge 0,$ where ${b1,dots,bs}$ are exactly the positions of the $0$’s in a binary string of length $n=s+t$. Lexicographic order on tuples $(bs,dots,b1)$ compares entries from left to right.

codeforcescompetitive-programming
CF 103269I - Walk in the Park

I don’t have the actual problem statement for Codeforces 103269I - Walk in the Park, so I can’t reliably reconstruct the solution or write a correct editorial.

codeforcescompetitive-programming
CF 103269H - Pet Pens (II)

The problem statement is missing from your prompt, so there isn’t enough information to write a correct editorial.

codeforcescompetitive-programming
CF 103269F - Cute Pets

I’m missing the actual problem statement for Codeforces 103269F - Cute Pets, so I can’t responsibly write a correct editorial yet.

codeforcescompetitive-programming
CF 103269G - Doggo Daycare

I’m missing the actual problem statement for Codeforces 103269G - Doggo Daycare (the input/output description and constraints are empty in your prompt).

codeforcescompetitive-programming
CF 103269E - Pet Pens (I)

I don’t have the actual statement for Codeforces 103269E - Pet Pens (I) in your prompt, so I can’t reliably reconstruct the problem or write a correct editorial.

codeforcescompetitive-programming
CF 103269D - Tallest Dogpark

I can’t write a correct editorial without the actual problem statement. Right now “Codeforces 103269D - Tallest Dogpark” is referenced, but the input/output description and rules are missing.

codeforcescompetitive-programming
CF 103269B - Abhilash's Cat

I can’t reliably reconstruct Codeforces 103269B “Abhilash’s Cat” from the title alone, and the editorial you’re asking for depends completely on the exact operations, constraints, and what is being optimized or computed.

codeforcescompetitive-programming
CF 103269C - Abhilash's Dog

I can’t produce a correct editorial yet because the actual problem statement for Codeforces 103269C - Abhilash’s Dog is missing from your prompt. Right now I don’t know: - what the input represents (array, graph, grid, queries, etc.

codeforcescompetitive-programming
CF 103270J - Particular Pupper

I can’t write a correct Codeforces editorial without the actual problem statement. Right now I don’t know what “Particular Pupper” is asking for, so any attempt would turn into guessing the task, constraints, and solution, which would defeat the purpose of a rigorous…

codeforcescompetitive-programming
CF 103270L - Squeaky Toy War

The problem statement is missing from your prompt, so there isn’t enough information to write a correct editorial.

codeforcescompetitive-programming
CF 103270D - Tallest Dogpark

An $(s,t)$-combination in dual form is a strictly decreasing sequence $bs b{s-1} cdots b1 ge 0,$ where ${b1,dots,bs}$ are exactly the positions of the $0$’s in a binary string of length $n=s+t$. Lexicographic order on tuples $(bs,dots,b1)$ compares entries from left to right.

codeforcescompetitive-programming
CF 103270K - Rat Maze

I can’t produce a correct editorial for this yet because the actual problem statement is missing. “Codeforces 103270K - Rat Maze” could plausibly be a grid shortest path, a constrained BFS, a state-space search, or something involving keys and doors, but each of those…

codeforcescompetitive-programming
CF 103270I - Walk in the Park

The problem statement for Codeforces 103270I - Walk in the Park is missing from your prompt, so there’s no way to reliably reconstruct the task, constraints, or required algorithm.

codeforcescompetitive-programming
CF 103270H - Pet Pens (II)

I can’t reliably write a correct editorial for Codeforces 103270H - Pet Pens (II) because the problem statement is missing from your prompt.

codeforcescompetitive-programming
CF 103270G - Doggo Daycare

I’m missing the actual statement of Codeforces 103270G - Doggo Daycare, so I can’t reliably reconstruct the problem, constraints, or the intended solution path. Right now anything I write would be guesswork, which would defeat the purpose of a correct editorial.

codeforcescompetitive-programming
CF 103270F - Cute Pets

I can’t reliably reconstruct CF 103270F - Cute Pets from the title alone, and the statement section in your prompt is empty. Without the actual problem definition, any “editorial” would be guesswork and would very likely be wrong.

codeforcescompetitive-programming
CF 103270C - Abhilash's Dog

We are given a path made of discrete positions arranged in a straight line, and each position has a height value that we are free to choose.

codeforcescompetitive-programming
CF 103270E - Pet Pens (I)

I can’t reliably write a correct editorial for this problem yet because the statement is missing. Right now the prompt only provides the title “Pet Pens (I)”, but the actual rules, input format, constraints, and required output are empty.

codeforcescompetitive-programming
TAOCP 7.2.1.3 Exercise 43

Fix an integer $t \ge 1$.

taocpmathematicsalgorithmsvolume-4medium
CF 103274L - Leonel and the powers of two

An $(s,t)$-combination in dual form is a strictly decreasing sequence $bs b{s-1} cdots b1 ge 0,$ where ${b1,dots,bs}$ are exactly the positions of the $0$’s in a binary string of length $n=s+t$. Lexicographic order on tuples $(bs,dots,b1)$ compares entries from left to right.

codeforcescompetitive-programming
CF 103274K - Kids at the Party

I don’t have the actual statement for Codeforces 103274K - Kids at the Party in your prompt, so there’s no way to correctly reconstruct the solution or reason about constraints, edge cases, or the algorithm.

codeforcescompetitive-programming
CF 103274M - Moon Dancers

We are missing one crucial piece: the actual algorithmic structure of the task is not fully recoverable from the partial statement we initially saw, and the problem page text itself is incomplete/fragmented in typical Gym scraping output. The key line “F.

codeforcescompetitive-programming
CF 103274J - Just Send the Email

The problem statement section is empty, so there is no defined task to solve yet. Without the actual description of what “Just Send the Email” asks for, any editorial would be guesswork, and that would defeat the purpose of a Codeforces-style explanation.

codeforcescompetitive-programming
CF 103274A - Alien Crop Triangles

An $(s,t)$-combination in dual form is a strictly decreasing sequence $bs b{s-1} cdots b1 ge 0,$ where ${b1,dots,bs}$ are exactly the positions of the $0$’s in a binary string of length $n=s+t$. Lexicographic order on tuples $(bs,dots,b1)$ compares entries from left to right.

codeforcescompetitive-programming
CF 103274I - Introducing Teleporting Machine

The problem statement is missing, so there’s no way to reconstruct what “Introducing Teleporting Machine” is asking for or derive a correct algorithm.

codeforcescompetitive-programming
CF 103274H - HeatWave

I’m missing the actual statement of Codeforces 103274H - HeatWave in your prompt. Right now I only see placeholders for “Problem Statement / Input / Output”, so there’s no way to reconstruct the task reliably without guessing.

codeforcescompetitive-programming
CF 103274G - Game of Baker

The problem statement is missing, so I don’t have the actual rules, input format, or what “Game of Baker” is asking for. Right now I can’t write a correct editorial because anything I produce would be guesswork, and Codeforces problems vary too much for that to be safe.

codeforcescompetitive-programming
CF 103274F - Fixing Subtitles

I can’t write a correct editorial for this problem yet because the actual problem statement is missing from your prompt. Right now I don’t know: what “Fixing Subtitles” is asking to compute, what the input represents, or what constraints define the solution space.

codeforcescompetitive-programming
CF 103274E - Escape Room

I don’t have the actual statement for Codeforces 103274E - Escape Room in the prompt, so I can’t reliably reconstruct the problem or produce a correct editorial yet.

codeforcescompetitive-programming
CF 103274D - Delivering Pizza

I don’t have the actual statement for Codeforces 103274D - Delivering Pizza, so I can’t responsibly reconstruct the problem or derive an algorithm without guessing.

codeforcescompetitive-programming
CF 103274C - Cypher Decypher

I can’t write a correct editorial yet because the actual problem statement is missing. Right now I only know the title “Cypher Decypher”, but there’s no description of the input format, constraints, or what transformation is required.

codeforcescompetitive-programming
CF 103274B - Basel Problem

The problem statement is missing, so I don’t have enough information to reconstruct what 103274B - Basel Problem is actually asking.

codeforcescompetitive-programming
CF 103286B - Рудольф и генераторы тьмы

An $(s,t)$-combination in dual form is a strictly decreasing sequence $bs b{s-1} cdots b1 ge 0,$ where ${b1,dots,bs}$ are exactly the positions of the $0$’s in a binary string of length $n=s+t$. Lexicographic order on tuples $(bs,dots,b1)$ compares entries from left to right.

codeforcescompetitive-programming