Problems

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Total results29,414 problems

Halloween Bully
Medium6
Graph, Union-find+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Password Creation
Medium6
Bit manipulation, Binary search+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Triple Sort
Medium6
Math, Combinatorics+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Great Flood
Medium6
Union-find, Sorting+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Fenomenalni Fenjer
Medium6
Geometry, Sorting+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Array Rotation 6
Medium6
Implementation, Simulation+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Rotate the Array 7
Medium6
Matrix, Simulation+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Corrupt Judge
Medium6
Greedy, Implementation
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Elevator Pitch
Medium6
BFS, Matrix
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Family Fares
Medium6
Shortest path, Graph+1
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Fountain
Medium6
Array, Stack+2
No attempts yet
Time limit
1.5s
Memory limit
512 MB
Judgeable
A Logical Problem
Medium6
Implementation, String+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Operation Save the Raffle Prize! (Hard)
Medium6
Math, Number theory+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
MVP Diamond (Easy)
Medium6
Dynamic programming, Greedy+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
MVP Diamond (Normal)
Medium6
Dynamic programming, Brute force+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
String Game 2
Medium6
String, Sliding window+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Attendance Check
Medium6
Number theory, Prefix sum+2
No attempts yet
Time limit
0.1s
Memory limit
1024 MB
Judgeable
🎵I hate you, hate you, hate you so much, hate you, don't come near me, stop bothering me🎵 - 1
Medium6
Sorting, Intervals+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Viruses
Medium6
Graph, BFS
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Quantum Teleportation
Medium6
Shortest path, Graph
No attempts yet
Time limit
4s
Memory limit
512 MB
Judgeable
Robot Marathon
Medium6
Greedy, Binary search+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Automated Delivery Management
Medium6
Math, Greedy+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Big Linear Collider
Medium6
Stack, Sorting+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Shop
Medium6
Dynamic programming, Greedy+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Drift
Medium6
Math, Greedy+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Royal Dynasty
Medium6
Tree, DFS+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Arithmetic Progression
Medium6
Sorting, Math+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Game
Medium6
Game theory, Greedy+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Birthday
Medium6
Intervals, Heap+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Bessie's Revolution
Medium6
Graph, DFS+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Prizes
Medium6
Array, Prefix sum+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Cosmic Settlement
Medium6
Binary search, Math+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Hyper Checkers Score Counting
Medium6
Sorting, Two pointers+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Fortress Defense
Medium6
Greedy, Sorting+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Communication Network Between Vertices
Medium6
Math, Number theory+2
No attempts yet
Time limit
1s
Memory limit
1536 MB
Judgeable
Prize Distribution
Medium6
Sorting, Greedy+1
No attempts yet
Time limit
1.5s
Memory limit
1536 MB
Judgeable
LCA and Queries
Medium6
Tree, Sorting+1
No attempts yet
Time limit
5s
Memory limit
1536 MB
Judgeable
Gap
Medium6
Binary search, Implementation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Album Manager
Medium6
Tree, Hash map+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Dictation
Medium6
Dynamic programming, String+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Taeyoung Throws Bombs
Medium6
Prefix sum, Implementation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Dino Game
Medium6
Dynamic programming, Combinatorics+2
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Restaurant Tour
Medium6
Graph, Topological sort+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Serious Business
Medium6
Dynamic programming, Prefix sum+2
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Recess Rocks
Medium6
Greedy, Sorting+2
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Rounded Work
Medium6
Math, Number theory+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Tea
Medium6
Math, Greedy+2
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Non-Trivial Common Divisor
Medium6
Number theory, Hash map+2
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Consistent Trading
Medium6
Union-find, Graph+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Rooks Game
Medium6
Graph, Union-find+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
The Spellbook
Medium6
Greedy, Sorting
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Bovine Genetics
Medium6
String, Dynamic programming
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Stuck in a Rut
Medium6
Simulation, Sorting+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Wind of Change 2020
Medium6
Tree, DFS+1
No attempts yet
Time limit
12s
Memory limit
1024 MB
Judgeable
Doomsday Escape
Medium6
Combinatorics, Implementation
No attempts yet
Time limit
7s
Memory limit
1024 MB
Judgeable
Python is too slow
Medium6
String, Stack+1
No attempts yet
Time limit
5s
Memory limit
1024 MB
Judgeable
Patkice II
Medium6
Graph, Shortest path+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Reading Room Distancing
Medium6
Simulation, Implementation+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Chrome
Medium6
Dynamic programming, Array+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Kart Rider
Medium6
Shortest path, Graph+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Mystery Sign
Medium6
Geometry, Binary search+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Science Fiction
Medium6
Graph, Greedy+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Social Distancing
Medium6
BFS, Binary search+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Forbidden Card
Medium6
Simulation, Array+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Exchange Bottleneck
Medium6
Graph, BFS+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Police Stations
Medium6
Binary search, Math+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Almost Balanced Tree
Medium6
Tree, Recursion+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Cryptoarithmetic Brain-Teaser
Medium6
Backtracking, String+1
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Lookup Performance
Medium6
Tree, Binary search+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Colored Squares
Medium6
Two pointers, Sliding window+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Spaceman Spoof's Functions
Medium6
Hash map, Simulation
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
SSB Tournament
Medium6
Graph, Combinatorics+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Temple Maze
Medium6
BFS, Bit manipulation+2
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Well, That's Just Grate
Medium6
Geometry, Implementation
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
AI Jeopardy
Medium6
Math, Binary search
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Gaggle
Medium6
Greedy, Graph+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Winning the Vote
Medium6
Dynamic programming, Implementation
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Tram
Medium6
Math, Geometry+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Finn the Giant
Medium6
Prefix sum, Two pointers+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Cucumber Conundrum
Medium6
Geometry, Math+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Alloys
Medium6
Math, Greedy+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Bonbons
Medium6
Greedy, Implementation+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Text Editor
Medium6
Shortest path, Brute force+1
No attempts yet
Time limit
3s
Memory limit
256 MB
Judgeable
Crushing blow
Medium6
Dynamic programming, Probability+2
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Bridge
Medium6
Greedy, Math+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Light Version of a Famous Task
Medium6
Number theory, Math+2
No attempts yet
Time limit
3s
Memory limit
256 MB
Judgeable
Integers and Ranges
Medium6
Dynamic programming, Intervals+1
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
TV Watching
Medium6
Greedy, Sorting+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Ferris Wheel
Medium6
Greedy, Heap
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Group Division
Medium6
Greedy, Union-find+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Studschiffret
Medium6
Simulation, Implementation+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Closing Ceremony
Medium6
Dynamic programming, Bit manipulation+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
School Graduation
Medium6
Union-find, Graph+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Fire Mountain
Medium6
BFS, Graph+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Kodkraft
Medium6
Sliding window, Two pointers+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Buying a carpet
Medium6
Math, Brute force+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Brickor
Medium6
BFS, Implementation+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Breakfast Buffet
Medium6
Game theory, Implementation+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Tower Building
Medium6
Dynamic programming, Sorting+2
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Lost in the Timetable
Medium6
String matching, Array+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable

Title	Level	Topics	Solved	Time limit	Memory limit	Judge
Halloween BullyGiven a graph of friendships with candy amounts, pick groups (connected components) whose total size stays under K, maximizing total candy.	Medium6	GraphUnion-find+2	No attempts yet	1s	1024 MB	Judgeable
Password CreationGiven N and a set of M used passwords, choose a password from 0 to N maximizing the minimum Hamming distance to any used password.	Medium6	Bit manipulationBinary search+2	No attempts yet	1s	1024 MB	Judgeable
Triple SortGiven a permutation of 1 to N, decide whether repeatedly reversing any three consecutive elements can sort it into increasing order.	Medium6	MathCombinatorics+2	No attempts yet	1s	1024 MB	Judgeable
Great FloodGiven region heights and travel times, find for each region the highest region its residents can reach while the rising water stays below their path.	Medium6	Union-findSorting+1	No attempts yet	1s	1024 MB	Judgeable
Fenomenalni FenjerPlace a point on the x-axis so that a circle of radius r centered there covers as many of the n given points as possible, and print that maximum count.	Medium6	GeometrySorting+2	No attempts yet	1s	512 MB	Judgeable
Array Rotation 6Given a 2^N by 2^N grid, apply R operations that flip or rotate each 2^l by 2^l block, or permute the blocks themselves, then print the final grid.	Medium6	ImplementationSimulation+2	No attempts yet	1s	512 MB	Judgeable
Rotate the Array 7Apply up to 1,000,000 flip and rotation operations at chosen block levels to a 2^N by 2^N array and print the final grid.	Medium6	MatrixSimulation+1	No attempts yet	1s	512 MB	Judgeable
Corrupt JudgeGiven each team's time penalty in rank order and the problem count p, decide whether every team's number of solved problems can be determined uniquely.	Medium6	GreedyImplementation	No attempts yet	1s	512 MB	Judgeable
Elevator PitchGiven a grid of floor counts, find the minimum number of elevators so that every floor of every building can be reached.	Medium6	BFSMatrix	No attempts yet	2s	512 MB	Judgeable
Family FaresFind the minimum total cost for each family member to reach station 1, choosing shortest-path individual tickets or one group ticket priced at g per person.	Medium6	Shortest pathGraph+1	No attempts yet	3s	512 MB	Judgeable
FountainEach reservoir overflows excess water into the nearest lower reservoir with a strictly larger diameter; answer where a given amount poured into reservoir R ends up.	Medium6	ArrayStack+2	No attempts yet	1.5s	512 MB	Judgeable
A Logical ProblemGiven ASCII logic circuit diagrams with AND and OR gates and inverted wires, evaluate the output for each list of 26 input bits.	Medium6	ImplementationString+1	No attempts yet	1s	512 MB	Judgeable
Operation Save the Raffle Prize! (Hard)Given a prime m and values Seed, X1, X2 produced by X1=(aSeed+c)%m and X2=(aX1+c)%m, recover any valid a and c.	Medium6	MathNumber theory+1	No attempts yet	1s	512 MB	Judgeable
MVP Diamond (Easy)Given each month's MVP grade, which depends on the sum paid over the current and previous month, find the maximum total amount paid over all N months.	Medium6	Dynamic programmingGreedy+2	No attempts yet	1s	512 MB	Judgeable
MVP Diamond (Normal)Given the monthly MVP tiers over N months and the tier thresholds, find the maximum total spending that produces exactly those tiers.	Medium6	Dynamic programmingBrute force+2	No attempts yet	1s	512 MB	Judgeable
String Game 2For each test case, find the shortest substring containing exactly K of some character, and the longest substring that both starts and ends with that character and contains exactly K of it.	Medium6	StringSliding window+2	No attempts yet	1s	1024 MB	Judgeable
Attendance CheckGiven sleeping students, Q sent codes, and M ranges, count numbers in each range that get no code from any divisor or multiple among the senders.	Medium6	Number theoryPrefix sum+2	No attempts yet	0.1s	1024 MB	Judgeable
🎵I hate you, hate you, hate you so much, hate you, don't come near me, stop bothering me🎵 - 1Given N half-open intervals [entry, exit), find the maximum number of simultaneously present mosquitoes and the earliest maximal interval achieving it.	Medium6	SortingIntervals+2	No attempts yet	1s	1024 MB	Judgeable
VirusesGiven each cell's virus preference order, find all stable viruses or all viable viruses, depending on the input flag p.	Medium6	GraphBFS	No attempts yet	1s	512 MB	Judgeable
Quantum TeleportationFind the cheapest chain of surviving processors from (1, 1) to (n, m), where each hop costs 2 raised to the Chebyshev distance between its endpoints.	Medium6	Shortest pathGraph	No attempts yet	4s	512 MB	Judgeable
Robot MarathonGiven finish times a_i for n robots on side-by-side lanes, find each robot's best and worst possible place over all choices of active signal devices.	Medium6	GreedyBinary search+2	No attempts yet	1s	512 MB	Judgeable
Automated Delivery ManagementGiven max parcel weight k and thresholds x and y, find the minimum possible total container weight at the moment a container is shipped.	Medium6	MathGreedy+2	No attempts yet	1s	512 MB	Judgeable
Big Linear ColliderParticles on a line move in fixed directions and annihilate when opposite charges meet; for each query time, count how many particles remain right after that moment.	Medium6	StackSorting+2	No attempts yet	1s	512 MB	Judgeable
ShopGiven item prices, split them into receipts so that on each receipt the cheapest floor(size/k) items are free, minimizing total payment.	Medium6	Dynamic programmingGreedy+2	No attempts yet	2s	512 MB	Judgeable
DriftFind the minimum time for a car with top speed v, acceleration a and braking b to cover two segments x and y joined by a 90 degree turn where the speed must drop to exactly 0.	Medium6	MathGreedy+2	No attempts yet	2s	512 MB	Judgeable
Royal DynastyGiven a rooted tree and queries (v, k), count the descendants of node v exactly k generations below it.	Medium6	TreeDFS+2	No attempts yet	2s	512 MB	Judgeable
Arithmetic ProgressionGiven 2n numbers, pick n of them that form an arithmetic progression and print its first term and common difference.	Medium6	SortingMath+1	No attempts yet	2s	512 MB	Judgeable
GamePlayers alternately append digits to a number; the player who first makes it reach or exceed n wins. Decide who wins under optimal play.	Medium6	Game theoryGreedy+2	No attempts yet	2s	512 MB	Judgeable
BirthdayPick the friends to invite so that each invited friend's share S/(k+1) lies within their [a_i, b_i] range and the total fun is maximized.	Medium6	IntervalsHeap+1	No attempts yet	2s	512 MB	Judgeable
Bessie's RevolutionCount empty cells whose removal disconnects the grid region containing that cell into at least two parts.	Medium6	GraphDFS+2	No attempts yet	1s	512 MB	Judgeable
PrizesFor each k from 2 to n, find the maximum prize value that is guaranteed among prizes 1..k when the host may remove one prize before Petya picks.	Medium6	ArrayPrefix sum+2	No attempts yet	1s	512 MB	Judgeable
Cosmic SettlementGiven n rectangles of size a by b and a w by h field, find the largest integer d such that n rectangles of size (a+2d) by (b+2d) fit in a grid on the field, in either orientation.	Medium6	Binary searchMath+1	No attempts yet	1s	512 MB	Judgeable
Hyper Checkers Score CountingCount distinct ordered triples (a,b,c) drawn from n given cards such that max(a,b,c) <= k * min(a,b,c).	Medium6	SortingTwo pointers+2	No attempts yet	1s	512 MB	Judgeable
Fortress DefenseDistribute exactly s defenders among wall sections, where each defender in section i repels k_i attackers, to minimize the total attackers that break through.	Medium6	GreedySorting+2	No attempts yet	2s	512 MB	Judgeable
Communication Network Between VerticesGiven a rooted tree and a frequency per node, count ancestor-descendant pairs whose frequencies divide one another. Since every parent index is smaller than the child, nodes are already topologically ordered.	Medium6	MathNumber theory+2	No attempts yet	1s	1536 MB	Judgeable
Prize DistributionChoose 7 of the N gift certificate values for the ranked prizes so the sorted prizes meet two inequality chains, maximizing their sum, or report -1.	Medium6	SortingGreedy+1	No attempts yet	1.5s	1536 MB	Judgeable
LCA and QueriesGiven a rooted tree and several queries, each listing K vertices, compute the sum of the LCA levels over all pairs of those vertices.	Medium6	TreeSorting+1	No attempts yet	5s	1536 MB	Judgeable
GapGiven an increasing sequence of N non-negative integers accessed only through a query function, return the largest gap between consecutive elements.	Medium6	Binary searchImplementation+2	No attempts yet	2s	512 MB	Judgeable
Album ManagerSimulate an album tree with add, delete, insert, and navigation commands, counting deleted albums and photos under each subtree.	Medium6	TreeHash map+2	No attempts yet	2s	512 MB	Judgeable
DictationCompute the edit distance between two strings, where a written 'i' matches i, j, l and a written 'v' matches v, w, but all other characters must match exactly.	Medium6	Dynamic programmingString+2	No attempts yet	1s	512 MB	Judgeable
Taeyoung Throws BombsGiven the altitude grid after all first explosions, recover how many bombs landed at each cell, where each bomb lowers an MxM square by 1.	Medium6	Prefix sumImplementation+2	No attempts yet	2s	512 MB	Judgeable
Dino GameCount binary-height maps of length N, starting on ground, containing at least one height-2 cactus, where no run of cactus heights can exceed a total the dinosaur can clear.	Medium6	Dynamic programmingCombinatorics+2	No attempts yet	2s	256 MB	Judgeable
Restaurant TourGiven a directed graph of N restaurants and M one-way roads, decide whether one walk can cover all restaurants, all roads, or both.	Medium6	GraphTopological sort+1	No attempts yet	3s	1024 MB	Judgeable
Serious BusinessCount the integers in [L, R] whose number of even-digit-sum contiguous substrings is odd, modulo 998244353, with R up to 100000 digits.	Medium6	Dynamic programmingPrefix sum+2	No attempts yet	3s	1024 MB	Judgeable
Recess RocksReorder the children so that the number who see someone ahead of them with at least as many rocks is minimized.	Medium6	GreedySorting+2	No attempts yet	3s	1024 MB	Judgeable
Rounded WorkGiven N, compute the expected value of round(A/B) when A and B are each chosen uniformly from 1 to N independently.	Medium6	MathNumber theory+2	No attempts yet	1s	1024 MB	Judgeable
TeaGiven n cups with amounts and initial temperatures, decide whether repeated splitting and mixing can produce the required amounts and target temperatures.	Medium6	MathGreedy+2	No attempts yet	2s	256 MB	Judgeable
Non-Trivial Common DivisorPick a subset of the given numbers that all share a common divisor greater than 1, maximizing the subset's sum.	Medium6	Number theoryHash map+2	No attempts yet	3s	512 MB	Judgeable
Consistent TradingDecide whether some cycle of exchange rules lets item counts grow without limit, where each rule trades one A for x copies of B.	Medium6	Union-findGraph+1	No attempts yet	2s	512 MB	Judgeable
Rooks GameGiven M rooks on an N x N board, a rook captures another when they share a row or column with nothing between them; find the minimum and maximum number of captures before no captures remain.	Medium6	GraphUnion-find+2	No attempts yet	2s	512 MB	Judgeable
The SpellbookGiven spell costs, up to k cookies that each lower one cost by 1, and starting MP m, find the minimum rest time to cast every spell once.	Medium6	GreedySorting	No attempts yet	2s	512 MB	Judgeable
Bovine GeneticsCount the original genomes that could produce a partly corrupted edited genome (split at equal neighbors, reverse each piece, concatenate), modulo 1e9+7.	Medium6	StringDynamic programming	No attempts yet	1s	512 MB	Judgeable
Stuck in a RutGiven N cows on an infinite grid that move north or east and eat grass as they go, find how much grass each cow eats, or Infinity if it never stops.	Medium6	SimulationSorting+1	No attempts yet	1s	512 MB	Judgeable
Wind of Change 2020Given two weighted trees on N vertices (edge weights may be negative), output one integer: the answer defined by the maximum distance over pairs of vertices in T1.	Medium6	TreeDFS+1	No attempts yet	12s	1024 MB	Judgeable
Doomsday EscapeDecide if all survivors can reach Mars by shuttle without any listed triple sharing a planet while the pilot is away.	Medium6	CombinatoricsImplementation	No attempts yet	7s	1024 MB	Judgeable
Python is too slowGiven a digit string where each '-' deletes the last digit, compute the exact sum of all intermediate integers as a big number.	Medium6	StringStack+1	No attempts yet	5s	1024 MB	Judgeable
Patkice IIChange the fewest map cells so the ducks can sail from the island o to the island x by following the currents, and output the resulting map.	Medium6	GraphShortest path+1	No attempts yet	2s	512 MB	Judgeable
Reading Room DistancingSimulate seat assignments for reservation holders who each pick the seat farthest from any occupied seat, then report how many minutes Mingyu's preferred seat stays free.	Medium6	SimulationImplementation+2	No attempts yet	1s	512 MB	Judgeable
ChromeGiven N tabs each with CPU and memory usage plus a priority, choose a subset whose total CPU and memory reach the targets M and K while minimizing the sum of priorities.	Medium6	Dynamic programmingArray+2	No attempts yet	1s	512 MB	Judgeable
Kart RiderFind the minimum time to drive from vertex 1 to vertex N when speed changes by at most 1 per vertex and each edge caps the speed.	Medium6	Shortest pathGraph+1	No attempts yet	1s	512 MB	Judgeable
Mystery SignGiven convex polygon A, convex polygon B inside it, and a polyline of K points, decide whether every sign point lies strictly inside A and strictly outside B, or count the violating points.	Medium6	GeometryBinary search+2	No attempts yet	2s	512 MB	Judgeable
Science FictionGiven a hypercube of 2^n planets holding distinct numbers, output fewer than 12000 swaps between wormhole-connected planets that sort them.	Medium6	GraphGreedy+1	No attempts yet	2s	512 MB	Judgeable
Social DistancingGiven a grid with patients, blocked seats, a start, and an end, find a walk from start to end that maximizes the minimum Chebyshev distance to any patient, or report safe or -1.	Medium6	BFSBinary search+2	No attempts yet	2s	512 MB	Judgeable
Forbidden CardGiven each player's two cards, count for every player how many forbidden numbers X make that player lose when everyone plays their first card first.	Medium6	SimulationArray+1	No attempts yet	1s	512 MB	Judgeable
Exchange BottleneckCities are built in order; each new city links either to every earlier city or only to the previous one, and the task is the maximum shortest-path distance over all pairs.	Medium6	GraphBFS+2	No attempts yet	1s	512 MB	Judgeable
Police StationsChoose integer coordinates for a control center and axis-aligned cable limits L and W so every station is reachable, minimizing L+W then L.	Medium6	Binary searchMath+2	No attempts yet	1s	512 MB	Judgeable
Almost Balanced TreeGiven A weight-1 nodes and B weight-2 nodes, build a binary tree where each node's two child subtree weights differ by at most 1, or print -1.	Medium6	TreeRecursion+1	No attempts yet	2s	512 MB	Judgeable
Cryptoarithmetic Brain-TeaserGiven two addend words, the task finds every dictionary word that makes their sum a letter-to-digit puzzle with exactly one valid solution.	Medium6	BacktrackingString+1	No attempts yet	5s	512 MB	Judgeable
Lookup PerformanceGiven a binary search tree and range queries [L, R], count how many times the recursive lookup function is called for each query.	Medium6	TreeBinary search+1	No attempts yet	2s	512 MB	Judgeable
Colored SquaresDelete at most k squares from a colored row so that the longest run of one color is as large as possible, and output that maximum run length.	Medium6	Two pointersSliding window+2	No attempts yet	1s	512 MB	Judgeable
Spaceman Spoof's FunctionsGiven functions f and g on 1 to n and a transcript of YES/NO answers from two logical heroes, find every x consistent with the answers, or print -1 on contradiction.	Medium6	Hash mapSimulation	No attempts yet	2s	512 MB	Judgeable
SSB TournamentCount triples of people that are either a triangle in the given acquaintance graph or an independent set of size three.	Medium6	GraphCombinatorics+2	No attempts yet	2s	512 MB	Judgeable
Temple MazeA square grid has walls, a start, a goal, up to 10 rune letters, and matching levers and gates; stepping on a lever opens every gate of that letter. Find the minimum number of moves to reach the goal, or IMPOSSIBLE.	Medium6	BFSBit manipulation+2	No attempts yet	3s	512 MB	Judgeable
Well, That's Just GrateFor each phone rectangle, decide whether its center lies outside the convex hull of all points where the wires cross the phone.	Medium6	GeometryImplementation	No attempts yet	2s	512 MB	Judgeable
AI JeopardyGiven a positive integer X up to 10^100, find n and k so that n choose k equals X, picking the smallest n and then the smallest k.	Medium6	MathBinary search	No attempts yet	1s	512 MB	Judgeable
GaggleGiven current mentor pointers, find the lexicographically best permutation with no fixed points that forms a single cycle through all Gagglers.	Medium6	GreedyGraph+1	No attempts yet	2s	512 MB	Judgeable
Winning the VoteGiven a vote order where 0 marks a teller, find the fewest adjacent swaps of a teller with a voter so party 1 wins, or report impossible.	Medium6	Dynamic programmingImplementation	No attempts yet	2s	512 MB	Judgeable
TramChoose the intercept a of the line y = x + a minimizing the sum of squared distances from given points to the line.	Medium6	MathGeometry+2	No attempts yet	1s	1024 MB	Judgeable
Finn the GiantGiven pillar strengths in a row, find the internal pillar whose removal starts the longest chain of collapsing pillars, and report the count and that pillar's index.	Medium6	Prefix sumTwo pointers+1	No attempts yet	1s	1024 MB	Judgeable
Cucumber ConundrumGiven a sandwich of radius s and pickles of radius r, find the most of n pickles that fit without overlap and cover at most z percent of the sandwich area.	Medium6	GeometryMath+1	No attempts yet	2s	512 MB	Judgeable
AlloysGiven a budget c per kilogram, choose titanium, aluminium, and magnesium ratios summing to 1 with x+y at most c to maximize hardness xy.	Medium6	MathGreedy+2	No attempts yet	1s	1024 MB	Judgeable
BonbonsGiven counts of three bonbon flavours for an R by C tray, find an arrangement where no two bonbons of the same flavour touch, or report that none exists.	Medium6	GreedyImplementation+1	No attempts yet	2s	512 MB	Judgeable
Text EditorFind the cheapest sequence of cursor moves, Shift selections, cuts, and pastes that turns the initial line order into the target order.	Medium6	Shortest pathBrute force+1	No attempts yet	3s	256 MB	Judgeable
Crushing blowFor each weapon (n dice with f faces plus modifier m), compute the probability that one roll reaches damage D, and print the best probability over all weapons.	Medium6	Dynamic programmingProbability+2	No attempts yet	2s	256 MB	Judgeable
BridgeGiven n old men on each side, rest time x, and crossing time t, find the minimum time for you to help all 2n men cross the bridge and return.	Medium6	GreedyMath+1	No attempts yet	1s	256 MB	Judgeable
Light Version of a Famous TaskFor each c up to 10^18, decide whether some a+b=c gives rad(abc) < c, where rad is the product of distinct primes.	Medium6	Number theoryMath+2	No attempts yet	3s	256 MB	Judgeable
Integers and RangesCount the digit strings of length n where the product of digits in every given range is divisible by 9, modulo 1e9+7.	Medium6	Dynamic programmingIntervals+1	No attempts yet	3s	512 MB	Judgeable
TV WatchingGiven parties on fixed days, each discussing certain TV series, decide whether Bob can watch every required series in time, at most 10 hours per day and no watching on party days.	Medium6	GreedySorting+2	No attempts yet	2s	1024 MB	Judgeable
Ferris WheelFind the minute when the last team finishes, with teams boarding the first free car in queue order and staying until all their turns are done.	Medium6	GreedyHeap	No attempts yet	1s	1024 MB	Judgeable
Group DivisionAssign each chair to group 1 or 2 so that every prefix is balanced within 1 and paired chairs match, choosing the lexicographically smallest sequence.	Medium6	GreedyUnion-find+2	No attempts yet	1s	1024 MB	Judgeable
StudschiffretSimulate a beam that travels diagonally through an N by M grid, bouncing off walls and skipping filled cells, to reconstruct the original plaintext from the row-by-row ciphertext.	Medium6	SimulationImplementation+2	No attempts yet	1s	1024 MB	Judgeable
Closing CeremonyGiven a row of up to 30 seats labeled A to D, find the maximum number of adjacent equal-group pairs after each person swaps at most once with someone within K seats.	Medium6	Dynamic programmingBit manipulation+2	No attempts yet	1s	1024 MB	Judgeable
School GraduationGiven an N by M grid of class letters, find the maximum number of colors so that cells in a shared column or class share a color.	Medium6	Union-findGraph+2	No attempts yet	2s	1024 MB	Judgeable
Fire MountainIn a grid where some cells are flames, find the shortest path from the top-left to the bottom-right cell while stepping on at most K flames.	Medium6	BFSGraph+2	No attempts yet	1s	1024 MB	Judgeable
KodkraftGiven a yearly contest schedule over K divisions, find the shortest window containing each division 1 through K in order, counting only contests that occur between his first and final win.	Medium6	Sliding windowTwo pointers+1	No attempts yet	2s	1024 MB	Judgeable
Buying a carpetGiven M and N, find integer side lengths L and B with M <= L*B <= N that minimize \|L - B\|, printing the shorter side first.	Medium6	MathBrute force+2	No attempts yet	1s	1024 MB	Judgeable
BrickorGiven a short row of black and white pieces, repeatedly remove an adjacent pair, flip both, and append them to either end, to turn all pieces white with the fewest moves.	Medium6	BFSImplementation+1	No attempts yet	1s	1024 MB	Judgeable
Breakfast BuffetPär and Oskar alternate eating dishes in a row, and the task is the largest sum of ratings Pär can guarantee for himself whatever Oskar does.	Medium6	Game theoryImplementation+1	No attempts yet	1s	1024 MB	Judgeable
Tower BuildingGiven N blocks each with a square width and height, stack a subset so width strictly decreases upward while height weakly increases upward, maximizing the total tower height.	Medium6	Dynamic programmingSorting+2	No attempts yet	3s	1024 MB	Judgeable
Lost in the TimetableGiven the seconds until each of N upcoming buses and a daily bus timetable, find every current time of day that matches the display.	Medium6	String matchingArray+1	No attempts yet	1s	1024 MB	Judgeable