Problems

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Total results29,463 problems

Election Time
Medium4
Sorting, Array+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
iCow
Medium4
Simulation, Implementation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Dining Cows
Medium4
Dynamic programming, Prefix sum+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Long Distance Racing
Medium4
Array, Prefix sum+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Lake Making
Medium4
Simulation, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Oh Those Rollers
Medium4
Graph, DFS+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Roads Around the Farm
Medium4
Recursion, Math+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Word Power
Medium4
String, Two pointers+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Clear and Present Danger
Medium4
Graph, Shortest path+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Clear Cold Water
Medium4
Tree, BFS+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Cow Pie Treasures
Medium4
Dynamic programming, Matrix
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Hungry Cows
Medium4
Dynamic programming, Binary search+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Word Games
Medium4
Implementation, Brute force+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Cow Picnic
Medium4
Graph, DFS+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
The Eating Puzzle
Medium4
Brute force, Bit manipulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
The Bale Tower
Medium4
Dynamic programming, Sorting+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Bronze Lilypad Pond
Medium4
BFS, Graph+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Buy One Get One Free
Medium4
Greedy, Sorting+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Argus
Medium4
Heap, Simulation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Cow Solitaire
Medium4
Dynamic programming, Matrix+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Bronze Cow Party
Medium4
Shortest path, Graph+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Team Arrangement
Medium4
Sorting, Greedy+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Barbara Bennett's Wild Numbers
Medium4
Combinatorics, Math+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Word Puzzle
Medium4
Array, Brute force+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
The die is cast
Medium4
DFS, BFS+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Smith Numbers
Medium4
Number theory, Math+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Date Bugs
Medium4
Brute force, Math+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
L-I-N-G-O
Medium4
String, Hash map+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Number Base Conversion
Medium4
Math, String+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Mutilated Morse Code Cipher
Medium4
String, Hash map+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Microprocessor Simulation
Medium4
Simulation, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Scramble Sort
Medium4
Sorting, String+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
N-Credible Mazes
Medium4
Graph, DFS+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Keywords
Medium4
String, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
The Sultan's Successors
Medium4
Backtracking, Recursion+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Theseus and the Minotaur
Medium4
Simulation, Graph+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Mapping the Route
Medium4
DFS, Backtracking+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Is It a Tree?
Medium4
Graph, Union-find+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Numerically Speaking
Medium4
Math, String+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Run, Run, Runaround Numbers
Medium4
Simulation, Brute force+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Optimal Array Multiplication Sequence
Medium4
Dynamic programming, Matrix+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Transferable Voting
Medium4
Simulation, Implementation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Pseudo-Random Numbers
Medium4
Hash map, Simulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Border
Medium4
Simulation, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Octal Fractions
Medium4
Math, String+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Risk
Medium4
Graph, BFS+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Volleyball Stats
Medium4
Implementation, Simulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Excuses, Excuses!
Medium4
String, Hash map+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
M*A*S*H
Medium4
Simulation, Array+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Radar Scopes
Medium4
Implementation, Geometry+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Message Routing
Medium4
Simulation, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Identifying Legal Pascal Real Constants
Medium4
String, Implementation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Inventory Maintenance
Medium4
Simulation, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Cowculations
Medium4
Implementation, Simulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Intersection of Two Lines
Medium4
Geometry, Math+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Making the Grade
Medium4
Implementation, Math+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Making Random Numbers
Medium4
Simulation, Hash map+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Bingo, Really?!
Medium4
String, Hash map+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Drink, on Ice
Medium4
Math, Implementation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Diplomatic License
Medium4
Geometry, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Etaoin Shrdlu
Medium4
String, Hash map+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Global Roaming
Medium4
Geometry, Math+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Guido van Rossum Built Python Out of Christmas Boredom
Medium4
Simulation, Bit manipulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Quad Tree
Medium4
Divide and conquer, Recursion+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Goldbach's Conjecture
Medium4
Number theory, Math+2
No attempts yet
Time limit
0.5s
Memory limit
256 MB
Judgeable
Binomial Showdown
Medium4
Math, Combinatorics+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Compromise
Medium4
Dynamic programming, String
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
The Sangbeom Building
Medium4
BFS, Graph+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Tree Recovery
Medium4
Tree, Recursion+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Knight Moves
Medium4
BFS, Graph+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Lotto
Medium4
Backtracking, Recursion+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Matrix Chain Multiplication
Medium4
Stack, Recursion+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Gregory the Grasshopper
Medium4
BFS, Graph+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Intergalactic Mortgage
Medium4
Simulation, Math+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Digital Display
Medium4
Implementation, Simulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Intriguing Identifiers
Medium4
Implementation, String+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Suspicious Stocks
Medium4
Array, Brute force+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Stock Exchange
Medium4
Array, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Calendar of Events
Medium4
Simulation, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Emag eht htiw Em Pleh
Medium4
Implementation, Simulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
English Number Translator
Medium4
String, Implementation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Amazing Four-Digit Numbers
Medium4
Implementation, Number theory+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Pizza Delivery
Medium4
Brute force, Math+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Who owns the Amiga?
Medium4
Brute force, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Budget
Medium4
Greedy, Math+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Jackpot
Medium4
Math, Number theory+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
R.Ø.L.P. Code Wheel
Medium4
String, Brute force+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
The Idiot of the Year Contest!
Medium4
Math, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Parsing Real Numbers
Medium4
String, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Expression Evaluator
Medium4
String, Simulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
The Happy Worm
Medium4
Sorting, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Bridge Transport
Medium4
Sliding window, Array+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Who is taller?
Medium4
Graph, DFS+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Palindrome Bases
Medium4
Math, Brute force+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Boring Business
Medium4
Simulation, Hash map+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Knight Hop
Medium4
BFS, Graph+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
From Prefix to Postfix
Medium4
Stack, Tree+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Pennies in the Ring
Medium4
Math, Geometry+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Maze
Medium4
BFS, Graph+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Keep on Truckin'
Medium4
Dynamic programming, Array+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable

Title	Level	Topics	Solved	Time limit	Memory limit	Judge
Election TimeEach cow has first round votes A and second round votes B; the top K by A advance, then the one with the largest B among them wins. Output the winner's index.	Medium4	SortingArray+2	No attempts yet	1s	128 MB	Judgeable
iCowRepeatedly pick the highest-rated song, reset its rating to 0, and spread its points over the others until T songs are played.	Medium4	SimulationImplementation+1	No attempts yet	1s	128 MB	Judgeable
Dining CowsGiven a sequence of 1s and 2s, find the minimum number of values to change so the sequence becomes nondecreasing.	Medium4	Dynamic programmingPrefix sum+2	No attempts yet	1s	128 MB	Judgeable
Long Distance RacingGiven a terrain string and per-unit times, find the farthest segment index k whose round-trip time stays within M seconds.	Medium4	ArrayPrefix sum+2	No attempts yet	1s	128 MB	Judgeable
Lake MakingApply each 3x3 stomp by flattening the block down to its maximum minus D, then sum water depth times 72*72 for squares below level E.	Medium4	SimulationImplementation+2	No attempts yet	1s	128 MB	Judgeable
Oh Those RollersRollers touch when the distance between centers equals the sum of radii. Starting from the roller at the origin, follow the chain to the roller that drives no other and print its coordinates.	Medium4	GraphDFS+2	No attempts yet	1s	128 MB	Judgeable
Roads Around the FarmGiven N cows and a difference K, a group of size s splits into two nonempty groups differing by K when possible; count the final grazing groups.	Medium4	RecursionMath+2	No attempts yet	1s	128 MB	Judgeable
Word PowerFor each of N cow names, count how many of M good strings appear as a case-insensitive subsequence of the name.	Medium4	StringTwo pointers+2	No attempts yet	1s	128 MB	Judgeable
Clear and Present DangerGiven a danger matrix and a required sequence of islands, find the minimum total danger of a walk that visits those islands in order, allowing detours through others.	Medium4	GraphShortest path+2	No attempts yet	1s	128 MB	Judgeable
Clear Cold WaterGiven a rooted binary tree described by branch points, print the distance from the barn to the endpoint of every pipe.	Medium4	TreeBFS+2	No attempts yet	1s	128 MB	Judgeable
Cow Pie TreasuresGiven an R by C grid of coin counts, find the maximum sum collected moving right one column each step, changing row by at most one, starting at (1,1) and ending at (R,C).	Medium4	Dynamic programmingMatrix	No attempts yet	1s	128 MB	Judgeable
Hungry CowsGiven a sequence of N cow brands, find the length of the longest strictly increasing subsequence in the given order.	Medium4	Dynamic programmingBinary search+2	No attempts yet	1s	128 MB	Judgeable
Word GamesGiven a rack of up to 10 letters with wildcards and a dictionary of up to 50000 words, print every dictionary word whose letters can be covered by the rack, in input order.	Medium4	ImplementationBrute force+2	No attempts yet	1s	128 MB	Judgeable
Cow PicnicGiven K starting pastures and a directed graph, count the pastures reachable from every one of the K starting positions.	Medium4	GraphDFS+2	No attempts yet	1s	128 MB	Judgeable
The Eating PuzzleGiven up to 21 bucket sizes and a calorie limit, choose a subset with the largest sum that does not exceed the limit.	Medium4	Brute forceBit manipulation+2	No attempts yet	1s	128 MB	Judgeable
The Bale TowerGiven up to 20 bales with distinct widths and breadths, find the longest chain where each bale is strictly smaller than the one below it.	Medium4	Dynamic programmingSorting+2	No attempts yet	1s	128 MB	Judgeable
Bronze Lilypad PondFind the minimum number of generalized knight's moves to get from the start lilypad to the destination on a grid, where only landing cells must be lilypads.	Medium4	BFSGraph+1	No attempts yet	1s	128 MB	Judgeable
Buy One Get One FreeBuy all N high quality bales, then pair as many of the M low quality bales as possible so each free bale is strictly smaller than its distinct high quality partner. Output N plus the maximum number of pairs.	Medium4	GreedySorting+2	No attempts yet	1s	128 MB	Judgeable
ArgusGiven queries that each fire every Period seconds starting at time Period, output the Q_num of the first K results, breaking ties by smaller Q_num.	Medium4	HeapSimulation+1	No attempts yet	1s	128 MB	Judgeable
Cow SolitaireGiven an N by N grid of cards with point values, find the maximum total score along a monotone path from the lower-left corner to the upper-right corner moving only right or up.	Medium4	Dynamic programmingMatrix+2	No attempts yet	1s	128 MB	Judgeable
Bronze Cow PartyGiven a connected undirected weighted graph, find twice the largest shortest-path distance from a fixed farm X, which is the longest round trip any cow makes.	Medium4	Shortest pathGraph+2	No attempts yet	1s	128 MB	Judgeable
Team ArrangementPick the lowest-numbered players for each role to match a formation, then name the selected player with the most years served as captain.	Medium4	SortingGreedy+2	No attempts yet	1s	128 MB	Judgeable
Barbara Bennett's Wild NumbersGiven a wild number W with digit and ? positions and a same-length number X, count the length-n digit strings matching W that are strictly greater than X.	Medium4	CombinatoricsMath+2	No attempts yet	1s	128 MB	Judgeable
Word PuzzleGiven a letter grid and a list of words, find each word's starting cell and one of eight reading directions, choosing the earliest match by row, column, then direction.	Medium4	ArrayBrute force+2	No attempts yet	1s	128 MB	Judgeable
The die is castGiven a grid picture of dice drawn with background, die, and dot pixels, count the connected dot regions inside each connected die region and print the counts sorted.	Medium4	DFSBFS+2	No attempts yet	1s	128 MB	Judgeable
Smith NumbersFor each input n, print the smallest Smith number larger than n, where a Smith number is a composite whose digit sum equals the digit sum of its prime factors.	Medium4	Number theoryMath+2	No attempts yet	1s	128 MB	Judgeable
Date BugsGiven up to 20 wrap-around year displays, find the smallest real year below 10000 consistent with every computer's shown value.	Medium4	Brute forceMath+2	No attempts yet	1s	128 MB	Judgeable
L-I-N-G-OGiven a secret five-letter word and guesses, print one feedback line per guess using upper-case for exact matches, lower-case for misplaced letters, and periods otherwise.	Medium4	StringHash map+2	No attempts yet	1s	128 MB	Judgeable
Number Base ConversionConvert a number given in one base to another base, where digits run 0-9, A-Z, a-z, and print a blank line after each conversion.	Medium4	MathString+2	No attempts yet	1s	128 MB	Judgeable
Mutilated Morse Code CipherApply Ohaver's symmetric Morse cipher: encode each message to dot-dash with a length string, reverse the lengths, and decode back to text.	Medium4	StringHash map+2	No attempts yet	1s	128 MB	Judgeable
Microprocessor SimulationSimulate a 4-bit microprocessor from a 256-word hex memory dump and print the final memory state when the stop instruction runs.	Medium4	SimulationImplementation+2	No attempts yet	1s	128 MB	Judgeable
Scramble SortSort words case-insensitively and integers numerically within each comma-separated list while keeping each element's original type position.	Medium4	SortingString+2	No attempts yet	1s	128 MB	Judgeable
N-Credible MazesGiven a dimension n and a list of paths between adjacent lattice points, decide if start and end coordinates are connected.	Medium4	GraphDFS+2	No attempts yet	1s	128 MB	Judgeable
KeywordsGiven keyword profiles with a gap threshold and a list of titles, report for each profile the numbers of titles where some pair of its distinct keywords appears within the threshold.	Medium4	StringImplementation+2	No attempts yet	1s	128 MB	Judgeable
The Sultan's SuccessorsFor each 8x8 board, place 8 non-attacking queens to maximize the sum of the numbers on the occupied squares.	Medium4	BacktrackingRecursion+2	No attempts yet	1s	128 MB	Judgeable
Theseus and the MinotaurSimulate a chase through a directed cavern maze where Theseus drops candles every k-th cavern and the Minotaur always takes its first exit not leading to a candle.	Medium4	SimulationGraph+1	No attempts yet	1s	128 MB	Judgeable
Mapping the RouteSimulate a west, north, east, south backtracking search on a small walled grid, number the route cells, mark other visited cells with ???, and draw the maze.	Medium4	DFSBacktracking+2	No attempts yet	1s	128 MB	Judgeable
Is It a Tree?For each test case, read directed edges until a pair of zeros and decide whether the graph is a tree under the three given conditions, printing the case number and verdict.	Medium4	GraphUnion-find+2	No attempts yet	1s	128 MB	Judgeable
Numerically SpeakingTranslate between lowercase words of length 1 to 20 and their bijective base-26 numbers, printing output in a padded two-column format.	Medium4	MathString+2	No attempts yet	1s	128 MB	Judgeable
Run, Run, Runaround NumbersFor each number R with 2 to 7 digits, find the smallest runaround number (distinct digits 1 to 9, jumps wrap around and visit every position once before returning) that is at least R.	Medium4	SimulationBrute force+1	No attempts yet	1s	128 MB	Judgeable
Optimal Array Multiplication SequenceGiven the dimensions of a chain of matrices, find the minimum number of scalar multiplications needed to compute their product.	Medium4	Dynamic programmingMatrix+2	No attempts yet	1s	128 MB	Judgeable
Transferable VotingSimulate an instant-runoff election with ranked ballots, discard invalid ones, eliminate lowest-vote candidates each round, and report the winner or the tied candidates.	Medium4	SimulationImplementation+1	No attempts yet	1s	128 MB	Judgeable
Pseudo-Random NumbersFor each quadruple (Z, I, M, L), follow the recurrence L = (Z*L + I) mod M and report how many distinct values appear before the sequence starts repeating.	Medium4	Hash mapSimulation+2	No attempts yet	1s	128 MB	Judgeable
BorderGiven a counter-clockwise closed grid path, mark every square that lies outside the region and shares an edge with the path, then print the 32 by 32 bitmap.	Medium4	SimulationImplementation+2	No attempts yet	1s	128 MB	Judgeable
Octal FractionsRead octal fractions from 0 to 1 and print each one's exact decimal value, with trailing zeros stripped.	Medium4	MathString+2	No attempts yet	1s	128 MB	Judgeable
RiskGiven a 20-country border graph, answer queries for the fewest countries to conquer when moving from one country to another, counting the destination.	Medium4	GraphBFS+2	No attempts yet	1s	128 MB	Judgeable
Volleyball StatsParse volleyball play-by-play lines, track kills, errors, hits, blocks, and digs per player and team, and print formatted reports on demand.	Medium4	ImplementationSimulation+2	No attempts yet	1s	128 MB	Judgeable
Excuses, Excuses!Find the excuses containing the most keyword occurrences, where keywords match case-insensitively and only as whole words.	Medium4	StringHash map+2	No attempts yet	1s	128 MB	Judgeable
MAS*HSimulate a card-driven counting-out lottery on a line of P people until X survivors remain, then print their original positions in increasing order.	Medium4	SimulationArray+2	No attempts yet	1s	128 MB	Judgeable
Radar ScopesGiven two radar sweeps five seconds apart, classify each plane as needing an equipment, intrusion, aloft, exited, or loss warning using distance and speed thresholds, then print sorted reports.	Medium4	ImplementationGeometry+2	No attempts yet	1s	128 MB	Judgeable
Message RoutingSimulate message routing through up to 10 MTAs whose tables use wildcards; report local delivery, routing loops, or unroutable messages.	Medium4	SimulationImplementation+2	No attempts yet	1s	128 MB	Judgeable
Identifying Legal Pascal Real ConstantsClassify each candidate line as a legal Pascal real constant or not, following the syntax rules for digits, decimal points, scale factors, and signs.	Medium4	StringImplementation+1	No attempts yet	1s	128 MB	Judgeable
Inventory MaintenanceProcess new, delete, buy, sell, and report commands over a small inventory, printing sorted item tables with exact dollar amounts and profit since the last report.	Medium4	SimulationImplementation+2	No attempts yet	1s	128 MB	Judgeable
CowculationsFor each tablet, simulate three operations (add, shift right, shift left, or null) on a five-symbol cow number and check the padded result equals the eight-symbol line.	Medium4	ImplementationSimulation+2	No attempts yet	1s	128 MB	Judgeable
Intersection of Two LinesGiven two lines each defined by two integer points, decide whether they meet at one point, are parallel, or coincide, printing the intersection rounded to two decimals.	Medium4	GeometryMath+2	No attempts yet	1s	128 MB	Judgeable
Making the GradeCompute each student's average after dropping the lowest test if more than two tests exist, then derive class mean and standard deviation, apply bonus and attendance letter-grade rules, and print the class GPA.	Medium4	ImplementationMath+2	No attempts yet	1s	128 MB	Judgeable
Making Random NumbersSimulate the middle-square method with four-digit numbers and count how many distinct values appear before the first repeat.	Medium4	SimulationHash map+2	No attempts yet	1s	256 MB	Judgeable
Bingo, Really?!Split the input into letter-only words, count distinct words per game ending at BULLSHIT, and print the running average as an irreducible fraction.	Medium4	StringHash map+2	No attempts yet	1s	128 MB	Judgeable
Drink, on IceGiven initial masses and temperatures of water and ice, find the equilibrium temperature and final amounts of ice and water after mixing. Each value rounds to one decimal.	Medium4	MathImplementation+1	No attempts yet	1s	128 MB	Judgeable
Diplomatic LicenseGiven an odd number of points around a circle, find for each adjacent pair the midpoint of the segment joining them, printed with six decimals.	Medium4	GeometryImplementation+2	No attempts yet	1s	128 MB	Judgeable
Etaoin ShrdluConcatenate each sample's lines, count overlapping adjacent character pairs, then print the five most frequent digrams with their counts and rounded relative frequencies.	Medium4	StringHash map+2	No attempts yet	1s	128 MB	Judgeable
Global RoamingGiven a satellite position and a list of ground locations on a sphere, decide which locations have the satellite above their horizon.	Medium4	GeometryMath+1	No attempts yet	1s	128 MB	Judgeable
Guido van Rossum Built Python Out of Christmas BoredomSimulate a tiny 8-bit von Neumann machine with 32 bytes of memory until it halts, then print the accumulator as 8-bit binary.	Medium4	SimulationBit manipulation+2	No attempts yet	1s	128 MB	Judgeable
Quad TreeParse an XBM hex bitmap, then recursively encode it as a quad tree: uniform squares become B or W, mixed ones become Q followed by four sub-squares.	Medium4	Divide and conquerRecursion+2	No attempts yet	1s	128 MB	Judgeable
Goldbach's ConjectureFor each even n up to one million, find the split into two odd primes with the largest difference, printing n = a + b.	Medium4	Number theoryMath+2	No attempts yet	0.5s	256 MB	Judgeable
Binomial ShowdownFor each pair (n, k), print the binomial coefficient C(n, k), stopping at the terminating pair 0 0.	Medium4	MathCombinatorics+1	No attempts yet	1s	128 MB	Judgeable
CompromiseFor each pair of word lists terminated by #, print the lexicographically smallest longest common subsequence of words.	Medium4	Dynamic programmingString	No attempts yet	1s	128 MB	Judgeable
The Sangbeom BuildingGiven a 3D grid of blocked and open cells with a start and an exit, find the minimum number of moves (or report impossible).	Medium4	BFSGraph+2	No attempts yet	1s	128 MB	Judgeable
Tree RecoveryGiven a binary tree's preorder and inorder traversal strings, print its postorder traversal. Process runs until end of file.	Medium4	TreeRecursion+1	No attempts yet	1s	128 MB	Judgeable
Knight MovesFor each pair of squares, find the minimum number of knight moves between them on a standard 8 by 8 chessboard.	Medium4	BFSGraph+1	No attempts yet	1s	128 MB	Judgeable
LottoFor each set of k numbers in ascending order, print all 6-element subsets in lexicographic order, separated by blank lines.	Medium4	BacktrackingRecursion+1	No attempts yet	1s	128 MB	Judgeable
Matrix Chain MultiplicationGiven matrices with dimensions and fully parenthesized products, report the elementary multiplication count or an error if dimensions mismatch.	Medium4	StackRecursion+1	No attempts yet	1s	128 MB	Judgeable
Gregory the GrasshopperFind the fewest knight moves from one square to another on a grid of up to 100 by 100, or report that it is impossible.	Medium4	BFSGraph+1	No attempts yet	1s	128 MB	Judgeable
Intergalactic MortgageSimulate monthly compound interest at r/12 percent on a debt, subtract a fixed payment, and report whether the balance reaches zero within N years.	Medium4	SimulationMath+2	No attempts yet	1s	128 MB	Judgeable
Digital DisplayRender each input time as a seven-segment digital clock face 29 characters wide and 7 rows tall, then print end after all times.	Medium4	ImplementationSimulation+2	No attempts yet	1s	128 MB	Judgeable
Intriguing IdentifiersValidate each given identifier as a Czech Personal ID for a birth between 1920 and 2009, and report the gender or mark it invalid.	Medium4	ImplementationString+2	No attempts yet	1s	256 MB	Judgeable
Suspicious StocksGiven daily stock prices and starting cash, buy as many whole shares as possible on one day, then sell all on a later day, and report the maximum profit.	Medium4	ArrayBrute force+2	No attempts yet	1s	128 MB	Judgeable
Stock ExchangeFor each issuer, for every bid output the agents on the opposite side whose price could match it, in input order.	Medium4	ArrayImplementation+2	No attempts yet	1s	128 MB	Judgeable
Calendar of EventsGiven old and new schedules of N meetings, simulate prefix reversals that place each target day and list the request sizes.	Medium4	SimulationImplementation+2	No attempts yet	1s	128 MB	Judgeable
Emag eht htiw Em PlehGiven White and Black piece lists, print the 8x8 chess board as ASCII art with alternating light and dark square fills.	Medium4	ImplementationSimulation+2	No attempts yet	1s	128 MB	Judgeable
English Number TranslatorParse English number words such as 'one thousand five hundred' into their integer value, handling negatives and an empty-line terminator.	Medium4	StringImplementation+1	No attempts yet	1s	128 MB	Judgeable
Amazing Four-Digit NumbersPrint every four-digit number whose digit sum is the same when written in base 10, base 12, and base 16.	Medium4	ImplementationNumber theory+1	No attempts yet	1s	128 MB	Judgeable
Pizza DeliveryGiven a weighted grid of delivery counts, find the crossing that minimizes the sum of Manhattan distances times weights, and output that minimum cost.	Medium4	Brute forceMath+2	No attempts yet	1s	128 MB	Judgeable
Who owns the Amiga?Given constraint lines over five rooms, decide whether the Amiga owner is uniquely determined and print that student, or state it cannot be found.	Medium4	Brute forceImplementation+2	No attempts yet	1s	128 MB	Judgeable
BudgetGiven row sums, column sums, and bound constraints on individual cells or whole rows/columns, decide whether a matrix of non-negative integers exists.	Medium4	GreedyMath+1	No attempts yet	1s	256 MB	Judgeable
JackpotFor each machine, given the periods at which each wheel shows the jackpot, output the least common multiple of the periods if it is at most 10^9, otherwise print a fixed message.	Medium4	MathNumber theory+1	No attempts yet	1s	128 MB	Judgeable
R.Ø.L.P. Code WheelFor each encoded message, try all 42 wheel shifts and print every decoding that contains the substring RØLP.	Medium4	StringBrute force+2	No attempts yet	1s	128 MB	Judgeable
The Idiot of the Year Contest!For each test case, count how many times a chosen digit occurs in the decimal representation of n! where n is at most 366.	Medium4	MathImplementation+2	No attempts yet	1s	128 MB	Judgeable
Parsing Real NumbersGiven T lines, decide whether each line is a valid real number with optional sign, decimal point, and exponent, allowing surrounding blanks.	Medium4	StringImplementation+2	No attempts yet	1s	128 MB	Judgeable
Expression EvaluatorEvaluate a C-style expression of letter variables with binary + and -, plus pre and post ++ and --, then report the result and each used variable's final value.	Medium4	StringSimulation+2	No attempts yet	1s	128 MB	Judgeable
The Happy WormCount maximal horizontal and vertical runs of empty cells that are at least 2 long in a field with stones.	Medium4	SortingImplementation+2	No attempts yet	1s	128 MB	Judgeable
Bridge TransportGiven car weights and a bridge that holds at most 4 cars, find the largest prefix that can cross without any window of 4 consecutive cars exceeding the weight limit.	Medium4	Sliding windowArray+2	No attempts yet	1s	128 MB	Judgeable
Who is taller?Given comparisons stating x is taller than y, decide whether p is taller than q, q is taller than p, or neither is known.	Medium4	GraphDFS+1	No attempts yet	1s	128 MB	Judgeable
Palindrome BasesFor a given X, list every base b with 2 <= b < X in which X is written as a palindrome.	Medium4	MathBrute force+1	No attempts yet	1s	256 MB	Judgeable
Boring BusinessSimulate a drill moving on a grid from a given start and fixed pre-existing path; after each command report the position and flag if any visited lattice point was already part of the borehole.	Medium4	SimulationHash map+1	No attempts yet	2s	512 MB	Judgeable
Knight HopOn an 8 by 8 board, find the fewest knight moves from a start square to a target square.	Medium4	BFSGraph+2	No attempts yet	2s	512 MB	Judgeable
From Prefix to PostfixTranslate each prefix arithmetic expression over + and - into its equivalent postfix form, stopping at the terminating 0.	Medium4	StackTree+2	No attempts yet	1s	128 MB	Judgeable
Pennies in the RingCount integer lattice points inside or on a circle of given radius for each radius until a 0 terminates input.	Medium4	MathGeometry+1	No attempts yet	1s	128 MB	Judgeable
MazeFind the shortest path in a grid where each cell dictates which directions you may exit, counting cells visited.	Medium4	BFSGraph+1	No attempts yet	1s	128 MB	Judgeable
Keep on Truckin'Given fixed and added motel distances, count overnight stop sequences where each day covers between A and B km.	Medium4	Dynamic programmingArray+1	No attempts yet	1s	128 MB	Judgeable