Problems

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Total results29,429 problems

Hongjun and the Fence
Hard8
Stack, Divide and conquer+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Buying Pancake Ingredients
Hard8
Matrix, Dynamic programming+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Mysterious Object
Hard8
Segment tree, Math+1
No attempts yet
Time limit
8s
Memory limit
128 MB
Judgeable
Proportional Representation
Hard8
Greedy, Binary search+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Antarctic Expedition
Hard8
Union-find, Tree+2
No attempts yet
Time limit
5s
Memory limit
128 MB
Judgeable
Parcel Delivery
Hard8
Shortest path, Dynamic programming+1
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Watermelon Throwing Game
Hard8
Matrix, Dynamic programming+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Apple Count
Hard8
Dynamic programming, Math+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Safe Deposit Business
Hard8
Number theory, Math+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Periodic Table
Hard8
Dynamic programming, Stack+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Road Network
Hard8
Shortest path, Graph+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Wall and Nails
Hard8
Geometry, Divide and conquer+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Grasshopper
Hard8
Dynamic programming, Matrix+1
No attempts yet
Time limit
4s
Memory limit
128 MB
Judgeable
Dungeon Escape
Hard8
Shortest path, BFS+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Frog Princess
Hard8
Segment tree, Simulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Highway
Hard8
Greedy, Sorting+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Wangnuni the Frog
Hard8
Dynamic programming, Sorting+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Gathering Cubes
Hard8
Simulation, Implementation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Number of Right Triangles
Hard8
Math, Geometry+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Bicycle Race
Hard8
Tree, Dynamic programming+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Circular Pebbles
Hard8
Math, Combinatorics+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Allowed Digit Multiples
Hard8
Dynamic programming, Math+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Rectangles in Three Dimensions
Hard8
Geometry, Sorting+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Study Leader Hongjun
Hard8
Segment tree, Binary search+1
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
Toy Tanks
Hard8
Greedy, Graph+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Military Base
Hard8
Geometry, Graph+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Minesweeper
Hard8
Backtracking, Brute force+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Buying a Highway
Hard8
Graph, Shortest path+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Bakery Line Order
Hard8
Graph, Greedy+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Grass
Hard8
Segment tree, Intervals+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Building a Wall
Hard8
Dynamic programming, Greedy+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Logo
Hard8
Graph, Math+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Mouse Traps
Hard8
Dynamic programming, Matrix+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Sheep Cloning
Hard8
Greedy, Number theory+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Flowers
Hard8
Sorting, Segment tree+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Scientist
Hard8
BFS, Dynamic programming+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Red Points and Blue Points
Hard8
Geometry, Binary search+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Concatenated Palindromes
Hard8
Combinatorics, Math+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Elephant
Hard8
Dynamic programming, Sorting+1
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
Splitting the Bureks
Hard8
Binary search, Geometry
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Image Square Lengths
Hard8
Matrix, Greedy+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Football Marathon
Hard8
Simulation, Math+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Train Ticket Inspection
Hard8
Greedy, Simulation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Tetris-Like Game
Hard8
Dynamic programming, Implementation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Crane
Hard8
Greedy, Simulation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Karla's Route
Hard8
BFS, Graph+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Reading Croatian Numbers
Hard8
Math, Binary search+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Triangle
Hard8
Geometry, Brute force+1
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
Fishermen
Hard8
Binary search, Greedy+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Swan Lake
Hard8
Binary search, BFS+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Roman Numeral Walk
Hard8
DFS, Backtracking+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Very Visible Point Pairs
Hard8
Divide and conquer, Geometry+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Balanced Bracket Segment
Hard8
Stack, String matching+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Banner Scheduling
Hard8
Dynamic programming, Greedy+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Martian DNA Formula
Hard8
Dynamic programming, String+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Ships on a River
Hard8
Dynamic programming, Greedy+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
JOKER
Hard8
Greedy, Simulation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Ant Tunnel
Hard8
Greedy, Simulation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Distance
Hard8
Prefix sum, Two pointers+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Slalom Shortest Path
Hard8
Geometry, Divide and conquer+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Radio Range Train Tour
Hard8
Graph, BFS+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
TOWER
Hard8
Union-find, Greedy+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Parking
Hard8
Tree, Greedy+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Loading Cattle onto Freight Cars
Hard8
Dynamic programming, Simulation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Beer Bottle Arrows
Hard8
Math, Simulation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Game
Hard8
Dynamic programming, Game theory+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Unidirectional Link Network
Hard8
Graph, Greedy+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Wedding Train
Hard8
Dynamic programming, Greedy+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Printed Circuit Board
Hard8
Geometry, Sorting+1
No attempts yet
Time limit
0.1s
Memory limit
32 MB
Judgeable
Sailing Race
Hard8
Dynamic programming, Geometry+1
No attempts yet
Time limit
3s
Memory limit
32 MB
Judgeable
Logo Matching
Hard8
String matching, Array+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Hotel
Hard8
Greedy, Heap+1
No attempts yet
Time limit
4s
Memory limit
128 MB
Judgeable
Traffic
Hard8
Graph, DFS+1
No attempts yet
Time limit
5s
Memory limit
128 MB
Judgeable
The Alliances
Hard8
Graph, Backtracking+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Bodyguards
Hard8
Greedy, Combinatorics+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
The MP3 Player
Hard8
Binary search, Greedy+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Insertion Sort vs Quicksort Comparisons
Hard8
Dynamic programming, Combinatorics+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Triangles
Hard8
Geometry, Sorting+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Dominance
Hard8
Geometry, Prefix sum+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Information
Hard8
Graph, Union-find+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Knights
Hard8
Game theory, Graph+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Fence
Hard8
Geometry, Dynamic programming+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Choosing Orders and Renting Machines
Hard8
Graph, Greedy+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Airport Show
Hard8
Simulation, Graph+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Antenna
Hard8
Geometry, Binary search+1
No attempts yet
Time limit
5s
Memory limit
32 MB
Judgeable
Walk
Hard8
Geometry, Shortest path+2
No attempts yet
Time limit
2s
Memory limit
64 MB
Judgeable
Connect
Hard8
Graph, Shortest path+1
No attempts yet
Time limit
0.5s
Memory limit
32 MB
Judgeable
Depot Rearrangement
Hard8
Graph, Greedy+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Mobile Service
Hard8
Dynamic programming, Greedy+1
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
Peaks
Hard8
Union-find, Sorting+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Fireworks in RightAngleles
Hard8
Binary search, Greedy+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Monument
Hard8
Binary search, Matrix+2
No attempts yet
Time limit
5s
Memory limit
128 MB
Judgeable
Building a Fence
Hard8
Geometry, Graph+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
City Planning
Hard8
Binary search, Greedy+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
RLE Compression
Hard8
Dynamic programming, String+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Moving Robots
Hard8
Dynamic programming, Simulation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Honeycomb Maximum Route Sum
Hard8
Dynamic programming, Matrix+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Who Wants to Live Forever?
Hard8
Bit manipulation, Math+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Graphic Madness
Hard8
Graph, Tree+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Racing Car Trail
Hard8
Graph, DFS+1
No attempts yet
Time limit
5s
Memory limit
128 MB
Judgeable

Title	Level	Topics	Solved	Time limit	Memory limit	Judge
Hongjun and the FenceGiven fence plank heights, find the minimum leftover area after optimally applying width-X roller strokes (each painting up to the min height of X consecutive planks) and the minimum number of strokes achieving that area.	Hard8	StackDivide and conquer+1	No attempts yet	1s	256 MB	Judgeable
Buying Pancake IngredientsCount walks from node 1 back to node 1 within K minutes on a directed graph where each edge can be crossed cheaply or with a shop visit collecting a subset of 4 ingredients, requiring all four collected, using state (node, ingredient mask) matrix exponentiation over a huge K.	Hard8	MatrixDynamic programming+2	No attempts yet	1s	128 MB	Judgeable
Mysterious ObjectSupport range updates that overwrite box X in [L,R] with ((X-L+1)*A) mod B, and answer range-sum queries over up to 10^9 boxes with 50000 operations.	Hard8	Segment treeMath+1	No attempts yet	8s	128 MB	Judgeable
Proportional RepresentationGiven partial vote counts, compute for every party the maximum and minimum seats it could receive under D'Hondt allocation with a 5% threshold, over all possible distributions of remaining votes.	Hard8	GreedyBinary search+2	No attempts yet	1s	128 MB	Judgeable
Antarctic ExpeditionProcess bridge, penguin-update, and route-sum queries on an incrementally connected forest, requiring dynamic connectivity checks and path-sum queries under updates.	Hard8	Union-findTree+2	No attempts yet	5s	128 MB	Judgeable
Parcel DeliveryFind minimum total cell-cost to visit an ordered sequence of targets on a grid where vertical movement is restricted to the first and last columns.	Hard8	Shortest pathDynamic programming+1	No attempts yet	2s	256 MB	Judgeable
Watermelon Throwing GameSimulate a watermelon-throwing process over up to 1e9 periods among 20 students, where each student's throw count parity depends on watermelons received, requiring matrix exponentiation or cycle detection to compute the total thrown.	Hard8	MatrixDynamic programming+1	No attempts yet	1s	128 MB	Judgeable
Apple CountGiven range [A,B] up to 10^15, sum for each number a value derived from run-length groups of equal digits, using digit-DP for efficiency.	Hard8	Dynamic programmingMath+1	No attempts yet	1s	128 MB	Judgeable
Safe Deposit BusinessGiven grid points on a plane watched by two guards with line-of-sight blocked by intermediate lattice points, count vaults seen by zero, one, or both guards, using number theory (gcd/visibility) and careful counting over huge L.	Hard8	Number theoryMath+2	No attempts yet	1s	128 MB	Judgeable
Periodic TableCount ways to place K non-attacking pieces on a histogram-shaped grid where two cells in the same row are close only if all columns between them reach that row, modulo 1e9+7.	Hard8	Dynamic programmingStack+1	No attempts yet	1s	128 MB	Judgeable
Road NetworkGiven a directed weighted graph, count for every edge how many shortest paths (over all source-destination pairs) use that edge, modulo 1e9+7.	Hard8	Shortest pathGraph+1	No attempts yet	1s	128 MB	Judgeable
Wall and NailsRepeatedly compute the convex hull area of a shrinking nail set as extreme points (leftmost, rightmost, highest, lowest) are removed one by one.	Hard8	GeometryDivide and conquer+1	No attempts yet	1s	128 MB	Judgeable
GrasshopperGiven an N×N grid and a special knight-like move rule requiring strictly increasing petal counts, find the longest such path starting from a given cell.	Hard8	Dynamic programmingMatrix+1	No attempts yet	4s	128 MB	Judgeable
Dungeon EscapeFind the shortest path from room 1 to room N in an infinite square spiral graph, using standard passages plus given extra shortcut edges derived from spiral geometry.	Hard8	Shortest pathBFS+2	No attempts yet	1s	128 MB	Judgeable
Frog PrincessSimulate a frog jumping to the nearest plant along diagonal directions, removing the departed plant each time, over up to 100,000 moves and plants.	Hard8	Segment treeSimulation+2	No attempts yet	1s	128 MB	Judgeable
HighwayGiven entry and exit points of N trucks, reassign entry tickets to exit interchanges (no truck keeping its own ticket) to minimize total absolute-difference toll.	Hard8	GreedySorting+1	No attempts yet	1s	128 MB	Judgeable
Wangnuni the FrogFind the path from leaf 1 to leaf N using only rightward or upward axis-aligned jumps costing K power each, that maximizes leftover power after eating flies along the way.	Hard8	Dynamic programmingSorting+1	No attempts yet	1s	128 MB	Judgeable
Gathering CubesGiven initial positions of a robot and five magnetic cubes on a grid, output a bounded move sequence that pushes the cubes into a fixed T pentomino shape.	Hard8	SimulationImplementation+1	No attempts yet	1s	128 MB	Judgeable
Number of Right TrianglesGiven up to 1500 planar points, count triples forming a right triangle, requiring an approach faster than brute force O(N^3).	Hard8	MathGeometry+1	No attempts yet	1s	128 MB	Judgeable
Bicycle RaceGiven a graph where every edge belongs to at most one cycle, find the longest walk ending at city 1 using each edge at most once.	Hard8	TreeDynamic programming+1	No attempts yet	1s	128 MB	Judgeable
Circular PebblesGiven a circular pebble sequence and a target obtained by applying K rounds of a XOR-like neighbor transformation, count distinct rotation classes of initial circles mapping to it after exactly K steps.	Hard8	MathCombinatorics+1	No attempts yet	1s	128 MB	Judgeable
Allowed Digit MultiplesCount multiples of X within [A,B] whose decimal digits all come from an allowed digit set, with values up to 10^11.	Hard8	Dynamic programmingMath+1	No attempts yet	1s	128 MB	Judgeable
Rectangles in Three DimensionsGiven N axis-aligned rectangles in 3D each parallel to one coordinate plane, count pairs of rectangles that intersect in at least one point.	Hard8	GeometrySorting+2	No attempts yet	1s	128 MB	Judgeable
Study Leader HongjunMaintain a dynamic set of (A,B) student pairs supporting insertion and queries for the student with minimal B difference (tie-broken by minimal A difference) among those with B >= B_i and A > A_i or (B=B_i and A>A_i).	Hard8	Segment treeBinary search+1	No attempts yet	3s	128 MB	Judgeable
Toy TanksGiven N tanks on an N by N board, find an assignment producing one tank per row and column, minimizing total moves, and output the exact move sequence.	Hard8	GreedyGraph+1	No attempts yet	1s	128 MB	Judgeable
Military BaseGiven up to 20 line-segment trenches, count unordered triples of intersection/endpoint points that are mutually visible along the trench network, meaning every pair's connecting segment lies fully on the union of trenches and no third point lies strictly between them.	Hard8	GeometryGraph+1	No attempts yet	1s	128 MB	Judgeable
MinesweeperGiven an N x N board whose border cells hold clue digits, place mines in the interior cells to satisfy every clue while maximizing total mines placed.	Hard8	BacktrackingBrute force+1	No attempts yet	1s	128 MB	Judgeable
Buying a HighwayGiven road segment purchase costs and trucks with routes and toll fees under a per-segment per-direction traffic cap K, minimize total cost of buying segments plus tolls paid.	Hard8	GraphShortest path+1	No attempts yet	1s	128 MB	Judgeable
Bakery Line OrderGiven a friendship graph, find any arrival order in which people join a line by a friend-insertion rule so the final line is exactly 1..N, or report impossible.	Hard8	GraphGreedy+1	No attempts yet	1s	128 MB	Judgeable
GrassSimulate N up to 1e9 plants under growth, cap, mow-left, mow-right, and clamp operations using an implicit interval structure, answering running sum queries efficiently.	Hard8	Segment treeIntervals+2	No attempts yet	1s	128 MB	Judgeable
Building a WallGiven block sizes/costs and two target wall silhouettes for horizontal and vertical placement days, compute the minimum total cost to build the wall over two days.	Hard8	Dynamic programmingGreedy+1	No attempts yet	1s	128 MB	Judgeable
LogoGiven N axis-aligned rectangles, compute the minimum number of pen-lift commands needed for a turtle to trace all rectangle boundaries without drawing extra lines.	Hard8	GraphMath+1	No attempts yet	1s	128 MB	Judgeable
Mouse TrapsGiven an N x N grid of trap counts, choose K consecutive cells per row to remove so no path exists left-to-right or top-to-bottom, maximizing removed traps.	Hard8	Dynamic programmingMatrix+1	No attempts yet	1s	128 MB	Judgeable
Sheep CloningDesign a minimum-length sequence of ENTER and CLONE commands so every cloning machine's sheep count reaches its exact target capacity via prime multiplications shared across machines under a per-command size limit.	Hard8	GreedyNumber theory+2	No attempts yet	1s	128 MB	Judgeable
FlowersFor each flower, find the rectangle formed by nearest boundary hits in four directions and count strictly interior flowers, using offline sweeps and range structures.	Hard8	SortingSegment tree+1	No attempts yet	1s	128 MB	Judgeable
ScientistGiven a grid maze and a sequence of box-shift events caused by a hidden mouse pushing box edges, compute the minimum number of mouse moves consistent with the observed box movements.	Hard8	BFSDynamic programming+1	No attempts yet	2s	128 MB	Judgeable
Red Points and Blue PointsGiven red and blue points on a plane, find two parallel lines (avoiding all points, excluding all blue points from the strip) that maximize red points strictly between them.	Hard8	GeometryBinary search+1	No attempts yet	1s	128 MB	Judgeable
Concatenated PalindromesCount N-digit numbers formed by concatenating two equal-length palindromes (first not starting with 0) that are divisible by M.	Hard8	CombinatoricsMath+1	No attempts yet	1s	128 MB	Judgeable
ElephantGiven N distinct 2D points, find the length of the longest strictly increasing chain in both coordinates and count how many such maximum chains exist modulo 1e9+7.	Hard8	Dynamic programmingSorting+1	No attempts yet	3s	128 MB	Judgeable
Splitting the BureksGiven two convex polygons separated by the y-axis, find the unique line y=Ax+B that bisects the area of both polygons simultaneously.	Hard8	Binary searchGeometry	No attempts yet	1s	128 MB	Judgeable
Image Square LengthsGiven a grid showing the topmost color at each pixel from K sequentially drawn axis-aligned squares, determine for each color the minimum and maximum possible side length consistent with the final image.	Hard8	MatrixGreedy+2	No attempts yet	1s	128 MB	Judgeable
Football MarathonSimulate a huge round-robin elimination marathon with up to 10^14 matches and output each team's total match count, requiring cycle detection to skip the brute-force simulation.	Hard8	SimulationMath+1	No attempts yet	1s	128 MB	Judgeable
Train Ticket InspectionGiven per-station boarding and alighting counts on a train with inspections on certain segments, find the min and max possible number of passengers whose tickets are never checked across all valid passenger assignments.	Hard8	GreedySimulation+1	No attempts yet	1s	128 MB	Judgeable
Tetris-Like GameGiven a score table for consecutive-letter group sizes, decide optimally which of three stack-like columns to drop each incoming letter into to maximize the total column score.	Hard8	Dynamic programmingImplementation+1	No attempts yet	1s	128 MB	Judgeable
CraneGiven N boxes each holding two colored balls, output a shortest crane command sequence that rearranges balls so all-white boxes and all-black boxes form contiguous groups.	Hard8	GreedySimulation+1	No attempts yet	1s	128 MB	Judgeable
Karla's RouteModify a grid by building at most K straight bridges over water and burning at most L forest components so a path exists from top-left to bottom-right.	Hard8	BFSGraph+1	No attempts yet	1s	128 MB	Judgeable
Reading Croatian NumbersGiven a letter and index N, find the N-th positive integer (up to 10^12) whose Croatian number reading starts with that letter, following specific rules about leading digits and place values.	Hard8	MathBinary search+2	No attempts yet	1s	128 MB	Judgeable
TriangleGiven up to 300 planar points, find three non-collinear points forming a triangle that contains the maximum number of the given points, counting boundary points.	Hard8	GeometryBrute force+1	No attempts yet	3s	128 MB	Judgeable
FishermenGiven fish production along towns on a line with transport losses proportional to distance, find the maximum equal number of children every town can feed via binary search on feasibility.	Hard8	Binary searchGreedy+1	No attempts yet	1s	128 MB	Judgeable
Swan LakeGiven a grid where ice melts by BFS layers each day, find the minimum number of days until two marked swan cells become connected through water.	Hard8	Binary searchBFS+1	No attempts yet	1s	256 MB	Judgeable
Roman Numeral WalkFind the longest path from the grid center through empty-separated cells that spells consecutive Roman numerals starting at 1, and print the last number reached.	Hard8	DFSBacktracking+2	No attempts yet	1s	128 MB	Judgeable
Very Visible Point PairsAfter each incremental point insertion, count pairs of points whose axis-aligned bounding rectangle contains no other current point, distinct x and y coordinates guaranteed.	Hard8	Divide and conquerGeometry+2	No attempts yet	1s	128 MB	Judgeable
Balanced Bracket SegmentMaintain a dynamic string under prefix/suffix bracket insertions and after each insertion report the shortest valid contiguous bracket substring covering the new character.	Hard8	StackString matching+1	No attempts yet	1s	128 MB	Judgeable
Banner SchedulingGiven N banner requests with fixed relative display-day patterns spanning at most 7 days, arriving in order with non-decreasing start days, find the minimum schedule length using at most K banner slots per day.	Hard8	Dynamic programmingGreedy+2	No attempts yet	1s	128 MB	Judgeable
Martian DNA FormulaCompress a DNA string into the shortest possible run-length style notation using nested parentheses with repeat counts.	Hard8	Dynamic programmingString+1	No attempts yet	2s	128 MB	Judgeable
Ships on a RiverGiven river fields with fish amounts and ships each needing a fixed anchor field and length placed without overlap, maximize total fish covered.	Hard8	Dynamic programmingGreedy+1	No attempts yet	1s	128 MB	Judgeable
JOKERGiven K shuffled and partly ambiguous card-removal records, decide if they can be reordered to remove all N-1 non-joker cards and output a valid execution order.	Hard8	GreedySimulation+1	No attempts yet	1s	128 MB	Judgeable
Ant TunnelGiven tunnel length, waiting spot positions, and arrival times of ants from both ends, compute the minimum time for all ants to finish crossing without opposite-direction collisions.	Hard8	GreedySimulation+1	No attempts yet	1s	128 MB	Judgeable
DistanceGiven a walk on a grid, find a contiguous segment of moves to delete so the remaining path stays within a bounding rectangle and ends as close as possible to the target point.	Hard8	Prefix sumTwo pointers+2	No attempts yet	1s	128 MB	Judgeable
Slalom Shortest PathGiven start, finish, and a sequence of horizontal gate segments at strictly decreasing y-coordinates, compute the length of the shortest path that touches each gate in order.	Hard8	GeometryDivide and conquer+2	No attempts yet	1s	128 MB	Judgeable
Radio Range Train TourGiven a town graph, find all towns Slavko can reach while continuously staying within distance D of Mirko as both move along tracks simultaneously.	Hard8	GraphBFS+1	No attempts yet	1s	128 MB	Judgeable
TOWERGiven a sequence of stack-merge operations on numbered cups, choose one extra initial merge move so that the largest resulting bunch after all merges is as big as possible.	Hard8	Union-findGreedy+1	No attempts yet	1s	128 MB	Judgeable
ParkingGiven a rooted tree garage with occupied rooms, find the minimum number of car pushes to clear the path from room P to the exit root, or report impossibility.	Hard8	TreeGreedy+1	No attempts yet	1s	128 MB	Judgeable
Loading Cattle onto Freight CarsPartition a sequence of animals into up to K contiguous car groups of size at most M, resolving chained attacker/protector fights inside each car, to maximize survivors.	Hard8	Dynamic programmingSimulation+1	No attempts yet	1s	128 MB	Judgeable
Beer Bottle ArrowsGiven a triangular pyramid of bottles each with an arrow, find the minimum number of clockwise/counter-clockwise triple-rotation moves to align all arrows upward.	Hard8	MathSimulation+1	No attempts yet	1s	128 MB	Judgeable
GameGiven a grid game where two players alternately move a token down, right, or diagonally with scoring foods, determine for each starting cell which player wins under optimal play.	Hard8	Dynamic programmingGame theory+1	No attempts yet	1s	128 MB	Judgeable
Unidirectional Link NetworkGiven a directed graph, partition nodes into disjoint simple rings or paths (following directed edges) to maximize total edge value, essentially a maximum weight matching style flow problem.	Hard8	GraphGreedy+1	No attempts yet	1s	128 MB	Judgeable
Wedding TrainArrange N guests in a line minimizing total adjacent height difference while keeping K given family members in a fixed relative order.	Hard8	Dynamic programmingGreedy+1	No attempts yet	1s	128 MB	Judgeable
Printed Circuit BoardGiven a simple polygon and an external origin point, find all polygon vertices that can be connected to the origin by a segment not crossing any polygon edge.	Hard8	GeometrySorting+1	No attempts yet	0.1s	32 MB	Judgeable
Sailing RaceFind the longest simple path on a circular arrangement of harbors using directed edges so that chords never cross except possibly one crossing involving the first stage, and report the max length with smallest starting harbor.	Hard8	Dynamic programmingGeometry+1	No attempts yet	3s	32 MB	Judgeable
Logo MatchingGiven a permutation pattern of length n and a sequence of m distinct heights, find all starting positions where a length-n window matches the relative order pattern.	Hard8	String matchingArray+1	No attempts yet	2s	128 MB	Judgeable
HotelGiven rooms with capacity and upkeep costs and requests with offered rent and minimum capacity, choose at most o request-room assignments maximizing total rent minus upkeep.	Hard8	GreedyHeap+1	No attempts yet	4s	128 MB	Judgeable
TrafficGiven a planar graph of junctions on an island with one-way and two-way streets, count for each western-side junction how many eastern-side junctions it can reach, exploiting planarity and geometric structure since streets cannot cross.	Hard8	GraphDFS+1	No attempts yet	5s	128 MB	Judgeable
The AlliancesDetermine if a grid of villages requiring exact alliance counts (with a directional twist for humans) admits a valid edge-selection satisfying all degree constraints.	Hard8	GraphBacktracking+1	No attempts yet	1s	128 MB	Judgeable
BodyguardsGiven row and column sums compressed into groups, decide if a 0/1 matrix exists matching those row and column sums (Gale-Ryser feasibility with huge grouped counts).	Hard8	GreedyCombinatorics+1	No attempts yet	1s	128 MB	Judgeable
The MP3 PlayerDetermine the largest lock timeout T and matching initial volume V1 so that a sequence of timed +/- presses on a lockable MP3 player ends at the given volume V2.	Hard8	Binary searchGreedy+1	No attempts yet	1s	128 MB	Judgeable
Insertion Sort vs Quicksort ComparisonsCount permutations of 1..N where insertion sort's comparison count exceeds quicksort's by between 1 and X, modulo 1234567.	Hard8	Dynamic programmingCombinatorics+2	No attempts yet	1s	128 MB	Judgeable
TrianglesGiven K points and M triangles each having the origin as one vertex, decide for each triangle whether any point lies strictly inside it, using geometric queries efficient for up to 100000 points and triangles.	Hard8	GeometrySorting+1	No attempts yet	1s	128 MB	Judgeable
DominanceGiven up to 3000 colored squares each with a Manhattan-distance attack range on a huge grid, count how many grid cells are dominated by white versus black using a diamond-shaped coverage counting technique.	Hard8	GeometryPrefix sum+1	No attempts yet	2s	128 MB	Judgeable
InformationDetermine whether a directed multigraph has two arc-disjoint spanning arborescences rooted at agent 1 covering all agents.	Hard8	GraphUnion-find+1	No attempts yet	1s	128 MB	Judgeable
KnightsDecide if the first player wins a combinatorial game where all knights with restricted moves must move simultaneously each turn until none can move.	Hard8	Game theoryGraph+1	No attempts yet	1s	128 MB	Judgeable
FenceChoose a subset of given points to form a convex polygon fence minimizing 20 times the number of posts used plus 111 times the number of trees left outside, considering all possible fences.	Hard8	GeometryDynamic programming+1	No attempts yet	1s	128 MB	Judgeable
Choosing Orders and Renting MachinesGiven orders with income and per-machine rent costs plus fixed machine purchase prices, choose orders and buy/rent decisions to maximize profit, solvable as a max-flow min-cut project selection problem.	Hard8	GraphGreedy+1	No attempts yet	2s	128 MB	Judgeable
Airport ShowDetermine whether two runway request sequences can interleave into a deadlock and, if so, output the lexicographically smallest interleaving sequence that causes it.	Hard8	SimulationGraph+1	No attempts yet	1s	128 MB	Judgeable
AntennaFind the minimum enclosing circle radius squared, as an exact fraction, for the smallest circle covering at least K of N given points.	Hard8	GeometryBinary search+1	No attempts yet	5s	32 MB	Judgeable
WalkCompute the shortest grid path length from (0,0) to (X,Y) avoiding up to 100,000 non-overlapping rectangular buildings that only occupy positive x squares.	Hard8	GeometryShortest path+2	No attempts yet	2s	64 MB	Judgeable
ConnectGiven a maze-like board with figures placed in rooms, pair up all figures and connect each pair with vertex-disjoint paths minimizing total path length.	Hard8	GraphShortest path+1	No attempts yet	0.5s	32 MB	Judgeable
Depot RearrangementFind the minimum number of single-item moves through one free slot to rearrange containers so every block of M consecutive positions contains all M distinct products, ending with the free slot restored.	Hard8	GraphGreedy+1	No attempts yet	2s	128 MB	Judgeable
Mobile ServiceGiven a cost matrix and a request sequence, find the minimum total cost of moving three servers to serve each request in order using optimal dynamic programming.	Hard8	Dynamic programmingGreedy+1	No attempts yet	3s	128 MB	Judgeable
PeaksGiven an elevation grid, find every peak flat-region and for each compute the maximum possible minimum elevation on a path leading to some strictly higher peak, using union-find over sorted elevations.	Hard8	Union-findSorting+1	No attempts yet	1s	128 MB	Judgeable
Fireworks in RightAnglelesChoose a vertical launch street V minimizing total Manhattan-like walking distance for citizens to reach nearest allowed point on the two crossing streets, respecting a safety gap S.	Hard8	Binary searchGreedy+1	No attempts yet	1s	128 MB	Judgeable
MonumentFind the maximum surface area 4ab of an axis-aligned a x a x b box of all-normal unit cubes that fits in a 3D grid with pores, where the square face can align with any of three axes.	Hard8	Binary searchMatrix+2	No attempts yet	5s	128 MB	Judgeable
Building a FenceFind the minimum-length axis-aligned rectilinear closed fence that encloses the main mansion's rectangle while avoiding the interiors of other forbidden rectangles.	Hard8	GeometryGraph+2	No attempts yet	1s	128 MB	Judgeable
City PlanningGiven N residents, transport cost T per distance unit, and increasing per-floor building costs up to K floors per lot, find the minimum total cost of building housing plus 30-year commuting across an infinite grid of lots.	Hard8	Binary searchGreedy+1	No attempts yet	1s	128 MB	Judgeable
RLE CompressionDecode a custom run-length encoding scheme and compute the minimum possible length of any code that decodes to the same character sequence.	Hard8	Dynamic programmingString+1	No attempts yet	1s	128 MB	Judgeable
Moving RobotsGiven several robots each with a bounded command sequence, find the minimum total deletions so all robots can be made to stop at one common grid cell, breaking ties by lexicographically smallest position.	Hard8	Dynamic programmingSimulation+1	No attempts yet	1s	128 MB	Judgeable
Honeycomb Maximum Route SumFind the maximum sum path through a hexagonal grid moving diagonally down-left or down-right, allowing one row to have its maximum value moved to any position once.	Hard8	Dynamic programmingMatrix+1	No attempts yet	1s	128 MB	Judgeable
Who Wants to Live Forever?Decide whether a bit string evolving under the Rule 90 XOR-neighbor cellular automaton eventually becomes all zeros or oscillates forever.	Hard8	Bit manipulationMath+2	No attempts yet	1s	128 MB	Judgeable
Graphic MadnessDecide whether a Hamiltonian cycle exists in a combined structure formed by two trees (with socket/processor degree rules) joined by a perfect matching between their sockets.	Hard8	GraphTree+2	No attempts yet	1s	128 MB	Judgeable
Racing Car TrailFor each empty cell in a grid, determine whether the first or second player wins a Tron-style trail game under perfect play, treated as a classic maximum matching / Sprague-Grundy style graph game.	Hard8	GraphDFS+1	No attempts yet	5s	128 MB	Judgeable