Problems

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Total results29,413 problems

Armrests
Medium6
Dynamic programming, Bit manipulation+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Bilda ord
Medium6
Backtracking, Combinatorics+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Smoke Signals
Medium6
String, Implementation+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Cubic Boxes
Medium6
Sorting, Dynamic programming+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Pekgalsvalsen
Medium6
Greedy, Sorting+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Hectic Harbour
Medium6
Dynamic programming, Simulation
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Mixtape Management
Medium6
String, Sorting+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Digit Card Game
Medium6
Brute force, Greedy+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Number Halli Galli Game
Medium6
Simulation, Queue+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Walking Is Annoying
Medium6
Greedy, BFS+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Priority Calculator
Medium6
Simulation, Linked list+1
No attempts yet
Time limit
1.5s
Memory limit
1024 MB
Judgeable
Seongsipdang
Medium6
Bit manipulation, Greedy+2
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Composite Factorization
Medium6
Math, Number theory+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Delivery Driver Minseo
Medium6
Math, Implementation+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Po
Medium6
Greedy, Stack+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Dance Mooves
Medium6
Union-find, Array+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Round Sugoroku
Medium6
Simulation, Implementation+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Furniture
Medium6
Union-find, Matrix+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Monochrome Points
Medium6
Greedy, Math
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Power Plant
Medium6
Tree, Dynamic programming
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Auction Market
Medium6
Greedy, Binary search+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Prize Coupon
Medium6
Dynamic programming, Greedy+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Door of the Ancient
Medium6
Dynamic programming, Greedy+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Sending Blessings
Medium6
Graph, Tree+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Domino Line
Medium6
Graph, Union-find+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Beautiful Permutation
Medium6
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Long Grid Covering
Medium6
Dynamic programming, Matrix
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Trade
Medium6
Binary search, Greedy+1
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Maximum Subsequence
Medium6
Dynamic programming, Bit manipulation+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
N-Queen 2
Medium6
Backtracking, Math
No attempts yet
Time limit
0.1s
Memory limit
512 MB
Judgeable
Ant Typing
Medium6
Dynamic programming, Greedy+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Condorcet
Medium6
Brute force, Graph+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Dominating Duos
Medium6
Stack, Array+1
No attempts yet
Time limit
4s
Memory limit
512 MB
Judgeable
Simply Sudoku
Medium6
Simulation, Implementation+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
LogDB
Medium6
String, Hash map+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Ride-Hailing
Medium6
Shortest path, Graph+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Redundant Binary Notation
Medium6
Dynamic programming, Combinatorics+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Safest Taxi
Medium6
Shortest path, Graph+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Early Orders
Medium6
Stack, Greedy+2
No attempts yet
Time limit
4s
Memory limit
1024 MB
Judgeable
Mentors
Medium6
Dynamic programming, Tree+1
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Figurines
Medium6
Segment tree, Implementation
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Comfortable Cows
Medium6
Implementation, Hash map+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Absenteeism
Medium6
Intervals, Sorting+1
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Cyclically Shifted Maze
Medium6
Matrix, BFS+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Phone Hoseokman
Medium6
Math, Brute force+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Genealogy Restorer Hoseok
Medium6
Graph, DFS+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Sunset
Medium6
Binary search, Graph+1
No attempts yet
Time limit
9s
Memory limit
1024 MB
Judgeable
Three Triangles
Medium6
Geometry, Math+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Octopus
Medium6
Greedy, Math+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Mingyeom Numbers
Medium6
String, Dynamic programming+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Spica
Medium6
Graph, Implementation+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Quiz
Medium6
Greedy, Sorting+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Candy
Medium6
Dynamic programming, Math+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
T-shirts
Medium6
Greedy, Sorting+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Magic Show
Medium6
Dynamic programming, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Video Clips
Medium6
Graph, Binary search+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Kingdom Division
Medium6
Tree, DFS+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Surveillance
Medium6
Array, Matrix+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Hundraelva kronor
Medium6
Dynamic programming, Math+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Digital Clock
Medium6
Prefix sum, Two pointers+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Code Lock
Medium6
Bit manipulation, Combinatorics+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Kontringsattack
Medium6
Sorting, Greedy+2
No attempts yet
Time limit
4s
Memory limit
1024 MB
Judgeable
Buying Paintings
Medium6
Dynamic programming, Array
No attempts yet
Time limit
14s
Memory limit
1024 MB
Judgeable
Minigolf
Medium6
BFS, Graph+2
No attempts yet
Time limit
4s
Memory limit
1024 MB
Judgeable
Konami Code
Medium6
Dynamic programming, String+2
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
List Testing
Medium6
Linked list, Implementation+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Average distance
Medium6
Tree, DFS+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Lingo
Medium6
Probability, Combinatorics+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Pachinko
Medium6
Dynamic programming, Probability+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Ranking
Medium6
Sorting, Simulation+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Internet Banking
Medium6
Greedy, Implementation+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Fitness Club
Medium6
Dynamic programming, Greedy+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Racing
Medium6
BFS, Graph+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Alien Attack
Medium6
Geometry, Intervals+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Snow White and the n Dwarfs
Medium6
Greedy, Sorting+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Labyrinth
Medium6
BFS, Graph+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Beautiful Phone Numbers
Medium6
Dynamic programming, String+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Jogging in Manhattan
Medium6
Math, Geometry+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Next partition into terms
Medium6
Greedy, Math+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Beautiful Scoreboard
Medium6
Greedy, Number theory+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
An aisle seat, please
Medium6
Greedy, Math+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Archimedean Spiral
Medium6
Math, Geometry+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Expression
Medium6
Greedy, Math
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Playing with a Divider
Medium6
Geometry, Hash map+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Maximum Sum
Medium6
Prefix sum, Brute force+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Three-color repainting
Medium6
Graph, DFS+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Experiment
Medium6
Graph, Topological sort+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Proving Ground
Medium6
Geometry, Binary search
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
River
Medium6
Linked list, Simulation+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Forest Cutting
Medium6
Binary search, Math+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Laying Tiles
Medium6
Dynamic programming, Combinatorics+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Traffic Lights
Medium6
Math, Binary search+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Candy Boxes
Medium6
Math, Brute force
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Petya and the Robot
Medium6
Sorting, Binary search+1
No attempts yet
Time limit
25s
Memory limit
1024 MB
Judgeable
Birch Alley
Medium6
Geometry, Two pointers+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Capitals
Medium6
Tree, Dynamic programming+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Graphics Editor <<Chameleon>>
Medium6
Implementation, Simulation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Sea Battle
Medium6
Intervals, Implementation+1
No attempts yet
Time limit
15s
Memory limit
1024 MB
Judgeable
Circular Fireworks
Medium6
Greedy, Sorting+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Ancient Calendar
Medium6
String, Implementation+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable

Title	Level	Topics	Solved	Time limit	Memory limit	Judge
ArmrestsPeople sit in a ring; each person wants a specific combination of left and right armrests, and we maximize how many preferences can be satisfied since each armrest holds at most one arm.	Medium6	Dynamic programmingBit manipulation+2	No attempts yet	1s	1024 MB	Judgeable
Bilda ordCount permutations of N distinct letters that satisfy rules forcing a letter into given positions or requiring one letter to come immediately before another.	Medium6	BacktrackingCombinatorics+2	No attempts yet	1s	1024 MB	Judgeable
Smoke SignalsParse a 26-letter Morse table and four pause lengths, then decode a binary smoke-signal string into text.	Medium6	StringImplementation+2	No attempts yet	1s	1024 MB	Judgeable
Cubic BoxesGiven N colored cubes, find the shop visiting order and a nesting of boxes that leaves the fewest outer boxes.	Medium6	SortingDynamic programming+1	No attempts yet	1s	1024 MB	Judgeable
PekgalsvalsenGiven a string with K distinct letters, choose the order to write the letters so that the total right-arrow distance is minimized, and print that minimum.	Medium6	GreedySorting+2	No attempts yet	2s	1024 MB	Judgeable
Hectic HarbourTwo cranes on a gantry of n positions must finish their task lists in order without colliding; find the minimum number of time steps.	Medium6	Dynamic programmingSimulation	No attempts yet	3s	512 MB	Judgeable
Mixtape ManagementGiven a permutation p, output n distinct positive integers with no leading zeros that increase in lexicographic order and whose numeric order matches p.	Medium6	StringSorting+1	No attempts yet	1s	512 MB	Judgeable
Digit Card GameSplit a multiset of digit cards (6 and 9 interchangeable by rotation) into two numbers using every card, maximizing their product.	Medium6	Brute forceGreedy+2	No attempts yet	1s	512 MB	Judgeable
Number Halli Galli GameSimulates a two-deck Halli Galli card game for M rounds with ring rules on sums and tops, then reports who holds more cards.	Medium6	SimulationQueue+1	No attempts yet	1s	1024 MB	Judgeable
Walking Is AnnoyingGiven N rickshaws at sorted positions, each covering a range to its right, find the minimum number of transfers to reach point M without walking.	Medium6	GreedyBFS+2	No attempts yet	1s	1024 MB	Judgeable
Priority CalculatorEvaluate an expression of numbers joined by + - * / by repeatedly computing the pair with the largest result, breaking ties by precedence, then by position.	Medium6	SimulationLinked list+1	No attempts yet	1.5s	1024 MB	Judgeable
SeongsipdangList all 2^N binary strings of length N, starting from a given string, so that the total number of matching positions between consecutive strings is minimized.	Medium6	Bit manipulationGreedy+2	No attempts yet	3s	1024 MB	Judgeable
Composite FactorizationFactor N into a product of composite numbers, choosing the lexicographically smallest such sequence, or report that none exists.	Medium6	MathNumber theory+2	No attempts yet	1s	1024 MB	Judgeable
Delivery Driver MinseoMinseo visits points 0, -1, 1, -2, 2, -4, 4, ... in order; for each query x, report the first time she arrives at x.	Medium6	MathImplementation+2	No attempts yet	1s	1024 MB	Judgeable
PoGiven a nonnegative array built by adding positive values to nested or disjoint segments starting from zeros, find the minimum number of such segment additions needed.	Medium6	GreedyStack+2	No attempts yet	1s	512 MB	Judgeable
Dance MoovesGiven N cows and K swaps repeated until minute M, find for each cow how many distinct positions it ever occupies.	Medium6	Union-findArray+1	No attempts yet	2s	512 MB	Judgeable
Round SugorokuA piece bounces left and right along a row, reversing direction at X and at each # it clears, until every # is erased; report the total time.	Medium6	SimulationImplementation+2	No attempts yet	2s	1024 MB	Judgeable
FurnitureGiven a grid with furniture, decide for each query cell whether placing furniture there keeps a south-and-east path from the top-left to the bottom-right corner.	Medium6	Union-findMatrix+1	No attempts yet	1s	512 MB	Judgeable
Monochrome PointsGiven 2N points on a circle colored with N white and N black, find the maximum number of crossing pairs among white-black segments that match every point.	Medium6	GreedyMath	No attempts yet	1s	512 MB	Judgeable
Power PlantGiven a tree with generators on some bases, choose which switches to turn on so that profit is maximized, where an ON generator lying between two other ON generators on a path is broken.	Medium6	TreeDynamic programming	No attempts yet	1s	512 MB	Judgeable
Auction MarketBuyers in fixed order scan items left to right and bid on the first item they can afford or outbid, and we count how many items end up with a bidder.	Medium6	GreedyBinary search+2	No attempts yet	1s	512 MB	Judgeable
Prize CouponEach student has 0 to 3 coupons and may write only their own or an adjacent student's ID; maximize the number of distinct students named on at least one coupon.	Medium6	Dynamic programmingGreedy+2	No attempts yet	1s	512 MB	Judgeable
Door of the AncientChoose how many times to throw each item; every throw deals the item's current power, then doubles the power and halves the value, and you minimize the total value lost while reaching damage H.	Medium6	Dynamic programmingGreedy+2	No attempts yet	1s	512 MB	Judgeable
Sending BlessingsGiven a connected graph with N cities and N bridges (capacities C_i), answer Q max-flow queries between pairs of cities.	Medium6	GraphTree+2	No attempts yet	2s	512 MB	Judgeable
Domino LineEach domino is an edge between two values; partition all edges into the fewest trails, which by Euler path counting depends on odd-degree vertices per component.	Medium6	GraphUnion-find+2	No attempts yet	1s	512 MB	Judgeable
Beautiful PermutationGiven n, the task builds a permutation a where the absolute differences \|a_i - i\| also form a permutation of 0 to n-1, or reports NO when none exists.	Medium6	MathImplementation	No attempts yet	1s	512 MB	Judgeable
Long Grid CoveringCount the ways to tile a 3 by n grid with 3-cell pieces (rotations allowed) for n up to 10^18, modulo 10^9+7.	Medium6	Dynamic programmingMatrix	No attempts yet	2s	512 MB	Judgeable
TradeGiven n merchants with prices c_i and markup rates p_i, find the most souvenirs you can buy with budget S when each purchase raises the remaining prices by p_i.	Medium6	Binary searchGreedy+1	No attempts yet	2s	256 MB	Judgeable
Maximum SubsequencePermute a sequence of up to 16 integers so that its maximum contiguous subarray sum is as small as possible, and print that minimum.	Medium6	Dynamic programmingBit manipulation+2	No attempts yet	2s	1024 MB	Judgeable
N-Queen 2Place N queens on an N by N board so that no two attack each other, then print the column of the queen in each row.	Medium6	BacktrackingMath	No attempts yet	0.1s	512 MB	Judgeable
Ant TypingChoose an arrangement of the digits 1 to 9 on nine keys so an ant walking left or right types a given digit string in the fewest seconds.	Medium6	Dynamic programmingGreedy+2	No attempts yet	1s	512 MB	Judgeable
CondorcetGiven vote tallies for up to 5 candidates, find the fewest added voters whose rankings make every candidate lose at least one head-to-head matchup.	Medium6	Brute forceGraph+1	No attempts yet	2s	512 MB	Judgeable
Dominating DuosCount pairs (i, j) in a permutation where both endpoints exceed every element strictly between them, with n up to 10^6.	Medium6	StackArray+1	No attempts yet	4s	512 MB	Judgeable
Simply SudokuGiven a Sudoku grid, repeatedly apply the Single Value and Unique Location rules, then report whether the puzzle is fully solved and print the result.	Medium6	SimulationImplementation+2	No attempts yet	1s	1024 MB	Judgeable
LogDBParse a database of facts with parenthesized argument lists, then answer queries whose arguments may contain variables, counting matching fact occurrences.	Medium6	StringHash map+2	No attempts yet	1s	1024 MB	Judgeable
Ride-HailingGiven directed road travel times and scheduled trips with fixed pickup times, find the minimum number of drivers so every trip is served.	Medium6	Shortest pathGraph+2	No attempts yet	2s	1024 MB	Judgeable
Redundant Binary NotationCount how many ways N can be written in base 2 with digits from 0 to t and no leading zeros, modulo 998244353.	Medium6	Dynamic programmingCombinatorics+2	No attempts yet	1s	1024 MB	Judgeable
Safest TaxiFind the shortest time for each trip on a grid of lanes, using at most X left turns and Y lane changes.	Medium6	Shortest pathGraph+1	No attempts yet	1s	1024 MB	Judgeable
Early OrdersGiven a sequence where every value from 1 to k appears at least once, find the lexicographically smallest subsequence that contains each of those k values exactly once.	Medium6	StackGreedy+2	No attempts yet	4s	1024 MB	Judgeable
MentorsCount trees on ranks 1 to N where each mentor outranks their mentees, each member has at most two mentees, and rank R has none, modulo M.	Medium6	Dynamic programmingTree+1	No attempts yet	3s	512 MB	Judgeable
FigurinesGiven daily add and remove logs for N figurines, each step counts the shelved figurines at least x on a queried day, and the program outputs the final x.	Medium6	Segment treeImplementation	No attempts yet	3s	512 MB	Judgeable
Comfortable CowsCows arrive one at a time on a grid; after each arrival, report how many cows have exactly three occupied orthogonal neighbors.	Medium6	ImplementationHash map+2	No attempts yet	1s	512 MB	Judgeable
AbsenteeismFind Alex's arrival and departure times within [0, m] that keep his shift at most k hours and avoid every colleague's complaint, minimizing the time spent at work.	Medium6	IntervalsSorting+1	No attempts yet	3s	512 MB	Judgeable
Cyclically Shifted MazeGiven a maze that was cyclically shifted by some rows and columns, list every (row, column) shift that restores a connected maze.	Medium6	MatrixBFS+1	No attempts yet	2s	512 MB	Judgeable
Phone HoseokmanGiven the same number written in two unknown bases A and B, find the base-10 value X and the two bases, reporting Multiple or Impossible.	Medium6	MathBrute force+2	No attempts yet	1s	512 MB	Judgeable
Genealogy Restorer HoseokGiven each living person's known ancestor relations, reconstruct the forest of family trees and print founders plus every person's children in lexicographic order.	Medium6	GraphDFS+2	No attempts yet	1s	512 MB	Judgeable
SunsetFind the earliest time shadows form a walkable path from house 1 to the hotel's north side, or NATT if that time is not before K.	Medium6	Binary searchGraph+1	No attempts yet	9s	1024 MB	Judgeable
Three TrianglesGiven triangle vertices in a fixed coordinate setup, compute the areas of the original triangle, the triangle formed by altitude and perpendicular-bisector intersections, and its reflection.	Medium6	GeometryMath+2	No attempts yet	1s	512 MB	Judgeable
OctopusGiven N octopuses in a circle, each adjacent pair holds a numbered hand (1 to 8), find the lexicographically smallest length-N sequence of hand numbers that is realizable.	Medium6	GreedyMath+2	No attempts yet	1s	1024 MB	Judgeable
Mingyeom NumbersSplit a string of M and K into valid Mingyeom digits so that the concatenated decimal values are maximized and minimized.	Medium6	StringDynamic programming+1	No attempts yet	1s	1024 MB	Judgeable
SpicaGiven the 12 edges of a fixed 12-vertex graph with shuffled labels, determine which vertex is Spica, the topmost star in the figure.	Medium6	GraphImplementation+2	No attempts yet	1s	1024 MB	Judgeable
QuizPick at most K questions out of N, where finishing every question in a category adds a bonus B, and maximize the total score.	Medium6	GreedySorting+2	No attempts yet	1s	1024 MB	Judgeable
CandyPick a subset of bags to maximize remaining candy after all candy and anti-candy pairs annihilate; each bag holds up to 10 signed types.	Medium6	Dynamic programmingMath+2	No attempts yet	1s	1024 MB	Judgeable
T-shirtsEach of N contestants accepts t-shirt sizes in an interval [L[i], H[i]], and N t-shirt sizes are given; match as many contestants to shirts as possible.	Medium6	GreedySorting+2	No attempts yet	1s	1024 MB	Judgeable
Magic ShowPick a signed rabbit count for each round, spending at most K magicks in total, to maximize the sum of distances from each round's interval midpoint.	Medium6	Dynamic programmingMath	No attempts yet	1s	1024 MB	Judgeable
Video ClipsFor each starting video index, find which video a viewer reaches after watching M videos, where the next video after i is S[i].	Medium6	GraphBinary search+2	No attempts yet	2s	1024 MB	Judgeable
Kingdom DivisionSplit a tree of N cities into P connected parts whose city values all sum to the same total, and report each city's part.	Medium6	TreeDFS+1	No attempts yet	2s	1024 MB	Judgeable
SurveillanceCount every W x W subrectangle of a B x B matrix that equals a given pattern plus some constant offset.	Medium6	ArrayMatrix+2	No attempts yet	2s	1024 MB	Judgeable
Hundraelva kronorGiven N, find the fewest notes with values 1, 11, 111, ... that sum exactly to N.	Medium6	Dynamic programmingMath+2	No attempts yet	1s	1024 MB	Judgeable
Digital ClockGiven the total energy n consumed by a digital clock over a continuous on-interval within one day, count how many start times are possible.	Medium6	Prefix sumTwo pointers+2	No attempts yet	1s	1024 MB	Judgeable
Code LockCount the ways to rotate N discs of M segments each so that some column position is a hole on every disc.	Medium6	Bit manipulationCombinatorics+2	No attempts yet	1s	1024 MB	Judgeable
KontringsattackChoose the smallest K so that counting matches with \|F-S\|<=K as ties maximizes Friberg's wins minus Skog's wins.	Medium6	SortingGreedy+2	No attempts yet	4s	1024 MB	Judgeable
Buying PaintingsThe paintings sit in a line; walking between adjacent ones costs 1 second and buying painting i costs t_i. Choose k paintings to buy, starting and ending anywhere, so the total buying plus walking time is smallest.	Medium6	Dynamic programmingArray	No attempts yet	14s	1024 MB	Judgeable
MinigolfOn a grid with walls, a ball can be putted 1 to K cells in a straight line; find the fewest putts to reach the hole.	Medium6	BFSGraph+2	No attempts yet	4s	1024 MB	Judgeable
Konami CodeGiven a string over the buttons U, N, V, H, B, A, find the minimum number of extra presses inserted between the Konami code's characters, where presses before and after the code are free.	Medium6	Dynamic programmingString+2	No attempts yet	3s	1024 MB	Judgeable
List TestingDesign a sequence of linked-list commands (add, remove, pop, clear, size) that triggers bugs in as many of ten buggy doubly linked list implementations as possible.	Medium6	Linked listImplementation+2	No attempts yet	1s	1024 MB	Judgeable
Average distanceGiven a weighted tree, compute the average distance over all unordered pairs of vertices, within 1e-6 relative or absolute error.	Medium6	TreeDFS+2	No attempts yet	1s	1024 MB	Judgeable
LingoGiven an n by n grid of numbered and covered cells, find the chance that drawing k balls without replacement covers an entire row, column, or diagonal.	Medium6	ProbabilityCombinatorics+2	No attempts yet	2s	1024 MB	Judgeable
PachinkoGiven a grid with obstacles and numbered gates, drop a ball in one column to maximize expected winnings as it falls and splits 50/50 at each obstacle.	Medium6	Dynamic programmingProbability+2	No attempts yet	1s	1024 MB	Judgeable
RankingGiven contest runs, compute each team's solved count, total penalty time, and tie-break by the last moment their score differed, then output the ranking.	Medium6	SortingSimulation+2	No attempts yet	1s	1024 MB	Judgeable
Internet BankingGiven n equal-length strings, find the minimum number of character swaps between positions of two strings needed to make some string equal a target, and output the operations.	Medium6	GreedyImplementation+2	No attempts yet	2s	1024 MB	Judgeable
Fitness ClubAssign k lockers to n groups of visitors so that the number of lockers still locked at day's end is maximized, given each group's counts of visitors who lock and do not lock.	Medium6	Dynamic programmingGreedy+1	No attempts yet	2s	1024 MB	Judgeable
RacingA car slides from its cell toward a chosen wall, stops half the remaining distance from the first obstacle, and we need the fewest presses to reach the target.	Medium6	BFSGraph+2	No attempts yet	2s	1024 MB	Judgeable
Alien AttackEach ship is an isosceles right triangle with legs s pointing southwest; find the area of points on the ground hit by vertical beams through all ships.	Medium6	GeometryIntervals+2	No attempts yet	2s	1024 MB	Judgeable
Snow White and the n DwarfsOrder the dwarfs so that at some moment every dwarf is asleep at once; output the order or -1.	Medium6	GreedySorting+2	No attempts yet	2s	1024 MB	Judgeable
LabyrinthGiven a 3D grid of h levels with blocked cells, find the shortest time from the start on the top level to the goal on the bottom, where horizontal moves and floor-breaking drops each cost 5 seconds.	Medium6	BFSGraph+2	No attempts yet	2s	1024 MB	Judgeable
Beautiful Phone NumbersGiven a 7-digit phone number, split the digits with hyphens into groups of 2 to 4 digits so that the total pattern-based beauty score is maximized, and print the best split with its score.	Medium6	Dynamic programmingString+2	No attempts yet	2s	1024 MB	Judgeable
Jogging in ManhattanGiven navigator readings every t minutes, each within Manhattan distance d of Misha's true position, find all lattice points he can occupy at the final time.	Medium6	MathGeometry+2	No attempts yet	2s	1024 MB	Judgeable
Next partition into termsGiven a partition of n written in nondecreasing order, print the next partition in lexicographic order, or No solution if none exists.	Medium6	GreedyMath+2	No attempts yet	2s	1024 MB	Judgeable
Beautiful ScoreboardGiven n teams' solved counts and m problems, find the maximum total submissions so the scoreboard stays sorted and every count divides m.	Medium6	GreedyNumber theory+2	No attempts yet	2s	1024 MB	Judgeable
An aisle seat, pleasePlace n x-by-y seats and at least one aisle strip of width a in an l-by-w cabin so the number of seats sharing a side with an aisle is maximized.	Medium6	GreedyMath+2	No attempts yet	2s	1024 MB	Judgeable
Archimedean SpiralGiven the angular speed, radial speed, initial radius, and end time, find the axis-aligned bounding rectangle of the Archimedean spiral arc traced from time 0 to T.	Medium6	MathGeometry+2	No attempts yet	2s	1024 MB	Judgeable
ExpressionPlace + or * between each pair of adjacent numbers, without parentheses, so that the value of the resulting expression is maximized.	Medium6	GreedyMath	No attempts yet	2s	1024 MB	Judgeable
Playing with a DividerGiven up to 1000 grid points hit by a divider with fixed needle distance, find all distances such that every point can be paired with another point exactly that far away.	Medium6	GeometryHash map+2	No attempts yet	2s	1024 MB	Judgeable
Maximum SumGiven an m by n grid of integers, find the axis-aligned rectangle with the largest sum along its border and print that sum plus the corner coordinates.	Medium6	Prefix sumBrute force+2	No attempts yet	2s	1024 MB	Judgeable
Three-color repaintingRecolor every vertex of a graph with a color different from its current one so that no edge joins two vertices of the same color.	Medium6	GraphDFS+2	No attempts yet	2s	1024 MB	Judgeable
ExperimentSchedule n stages with precedence constraints, each needing one of two devices, to minimize the number of switches between devices.	Medium6	GraphTopological sort+2	No attempts yet	2s	1024 MB	Judgeable
Proving GroundGiven a convex polygon that does not contain the origin, find the minimum over all rays from the origin of the nearest distance times the farthest distance along that ray.	Medium6	GeometryBinary search	No attempts yet	2s	1024 MB	Judgeable
RiverMaintain a sequence of river segment lengths under splits and bankruptcies, reporting the sum of squares after the initial state and each of k events.	Medium6	Linked listSimulation+2	No attempts yet	1s	1024 MB	Judgeable
Forest CuttingTwo lumberjacks cut A and B trees per day but rest every K-th and M-th day; find the first day the total felled reaches X.	Medium6	Binary searchMath+2	No attempts yet	1s	1024 MB	Judgeable
Laying TilesCount tilings of a 2 by n corridor with 1x2 and 1x1 tiles, given some 1x1 tiles already placed, modulo 1e9+7.	Medium6	Dynamic programmingCombinatorics+2	No attempts yet	1s	1024 MB	Judgeable
Traffic LightsFind the maximum constant speed at which a cart can travel between two synchronized traffic lights, each green for a minutes and red for b minutes, with distance x.	Medium6	MathBinary search+2	No attempts yet	2s	1024 MB	Judgeable
Candy BoxesGiven N and a candy box of size a x b x c, find a large box whose three sides sum to at most N and that holds the most candy boxes in the same orientation.	Medium6	MathBrute force	No attempts yet	2s	1024 MB	Judgeable
Petya and the RobotRestore a hidden permutation of 1 to n by swapping two positions and reading the inversion count the Robot reports after each swap.	Medium6	SortingBinary search+1	No attempts yet	25s	1024 MB	Judgeable
Birch AlleyPick a contiguous run of birches on each side of a W-wide strip so that a ribbon of length L encloses the most birches, then print that count.	Medium6	GeometryTwo pointers+1	No attempts yet	2s	1024 MB	Judgeable
CapitalsGiven a tree of n cities, count the triples of cities where every pair is exactly d roads apart.	Medium6	TreeDynamic programming+1	No attempts yet	2s	1024 MB	Judgeable
Graphics Editor <<Chameleon>>Given an N x N picture of black and white cells, find a sequence of chameleon cursor moves that produces it, starting from a black cursor on a black top left cell.	Medium6	ImplementationSimulation	No attempts yet	1s	1024 MB	Judgeable
Sea BattleImplement a server for a 1 x N Sea Battle field with T ships of length K that reports a hit only on certainly occupied cells and the count of such cells.	Medium6	IntervalsImplementation+1	No attempts yet	15s	1024 MB	Judgeable
Circular FireworksGiven N piles in a circle, remove N-2 piles where each removal lowers both neighbors by 1, and find the smallest possible height of the taller of the last two piles.	Medium6	GreedySorting+1	No attempts yet	1s	256 MB	Judgeable
Ancient CalendarGiven an N by M table of digits where some digits are unknown (*), fill them in so each row is exactly 1 more than the previous row, then print the first row's number.	Medium6	StringImplementation+1	No attempts yet	1s	1024 MB	Judgeable