Problems

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Total results29,425 problems

Tile Cut
Hard8
Graph, Dynamic programming+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
A Classic Myth: Flatland Superhero
Hard8
Geometry, Divide and conquer+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Collateral Cleanup
Hard8
Geometry, Topological sort+2
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
LatticeLand
Hard8
BFS, Graph+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Locksmith
Hard8
Geometry, Simulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Zombie Swallows
Hard8
Dynamic programming, Bit manipulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
This Can't Go On Forever
Hard8
Number theory, Math+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Spare the Ewoks!
Hard8
Dynamic programming, Prefix sum+1
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
Laser Shot
Hard8
Geometry, Math+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Power Grid
Hard8
Dynamic programming, Graph+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Cave Crisis
Hard8
Geometry, Union-find+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Optimal Strategy for the ICPC
Hard8
Dynamic programming, Bit manipulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Repair Depots
Hard8
Binary search, Geometry+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Missile Command
Hard8
Geometry, Greedy+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Rubik's Cube
Hard8
Simulation, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Cover Up
Hard8
Probability, Dynamic programming+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Coffin Tiles
Hard8
Number theory, Brute force+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Operation: Merchant Boorinei
Hard8
Dynamic programming, Geometry+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Honeycomb, Honeycomb, Me Want Honeycomb!
Hard8
Geometry, Hash map+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Barcode of Judgment
Hard8
String, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Filtration
Hard8
Simulation, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Fill the Crossword
Hard8
Backtracking, Trie+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Core Wars
Hard8
Simulation, Implementation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Panic Room
Hard8
Graph, Minimum spanning tree+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Jetpack Sniper 3000 Fragfest Extreme
Hard8
Geometry, Implementation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
As the Crow Flies
Hard8
Graph, Shortest path+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
The Mark of a Wizard
Hard8
Graph, Shortest path+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Su-domino-ku
Hard8
Backtracking, DFS+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Top This
Hard8
Backtracking, Brute force+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Quick Search
Hard8
Graph, Dynamic programming+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Line & Circle Maze
Hard8
Geometry, Graph+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Slink
Hard8
Simulation, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Jump, Lizard!
Hard8
Graph, Shortest path+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Ink Blots
Hard8
Geometry, Graph+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Bright Bracelet
Hard8
Backtracking, Brute force+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Fax Regions
Hard8
Simulation, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Hilbert Curve
Hard8
Recursion, Divide and conquer+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Split Windows
Hard8
Tree, Recursion+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Edge Detection
Hard8
Simulation, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
The Doors
Hard8
Geometry, Graph+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Funhouse
Hard8
Graph, Shortest path+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Grimm's Conjecture
Hard8
Number theory, Math+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Stained Glass
Hard8
Backtracking, Brute force+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Selling Cells
Hard8
Geometry, Math+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Word Ladder
Hard8
Graph, BFS+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Out of Sight
Hard8
BFS, Simulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Crosswords Insider
Hard8
Backtracking, Simulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Doors and Penguins
Hard8
Geometry, Divide and conquer+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Zoned Out
Hard8
Simulation, Graph+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
GHOST
Hard8
Game theory, Trie+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Line of Sight
Hard8
Geometry, Sorting+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Unhappy Numbers
Hard8
Math, Dynamic programming+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Walls
Hard8
Geometry, Greedy+2
No attempts yet
Time limit
5s
Memory limit
128 MB
Judgeable
CosmoCraft
Hard8
Greedy, Simulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
The Red Gem
Hard8
Geometry, Intervals+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
The Worm in the Apple
Hard8
Geometry, Binary search+1
No attempts yet
Time limit
15s
Memory limit
128 MB
Judgeable
Sloppy Sort
Hard8
Dynamic programming, Bit manipulation+2
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
Function Overloading
Hard8
Dynamic programming, Implementation+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Catching Shade in Flatland
Hard8
Geometry, Math+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Supply Mission
Hard8
Brute force, Geometry+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Task Scheduling
Hard8
Shortest path, Graph+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Soccer
Hard8
Brute force, Implementation+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Papa
Hard8
Graph, Union-find+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
When
Hard8
Simulation, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
National Treasures
Hard8
Greedy, Minimum spanning tree+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Pattern Matching
Hard8
Dynamic programming, String matching
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Moving Sticks
Hard8
Brute force, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
A-to-Z
Hard8
Graph, Shortest path+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Alpha of Degree k
Hard8
Graph, BFS+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Queue Sort
Hard8
BFS, Simulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Weaker than Planned
Hard8
Backtracking, String+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Driving an Icosahedral Rover
Hard8
BFS, Simulation+2
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
City Merger
Hard8
Dynamic programming, Bit manipulation+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Captain Q's Treasure
Hard8
Backtracking, Brute force+2
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
ASCII Expression
Hard8
Implementation, Recursion+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Laser Beam Reflections
Hard8
Geometry, Brute force+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Tighten Up!
Hard8
Geometry, Greedy+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Roll a Big Ball
Hard8
Geometry, Binary search+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Dr. Podboq, or: How We Became Asymmetric
Hard8
Tree, DFS+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Hexerpents of Hexwamp
Hard8
BFS, Simulation+2
No attempts yet
Time limit
10s
Memory limit
128 MB
Judgeable
Water Tank
Hard8
Simulation, Sorting+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Name the Crossing
Hard8
Graph, Union-find+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Eco-driving
Hard8
Graph, Binary search+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Galactic Warlords
Hard8
Geometry, Combinatorics+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Infiltration
Hard8
String, Hash map+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Private Space
Hard8
Dynamic programming, Bit manipulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Enemy Division
Hard8
Graph, Greedy+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Connection
Hard8
Graph, Shortest path+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Borg Boogie
Hard8
Dynamic programming, Probability+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Polyomino Powers
Hard8
Brute force, Backtracking+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Statisticians
Hard8
Prefix sum, Binary search+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Speedy Escape
Hard8
Graph, Shortest path+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Flight Planning
Hard8
Tree, DFS+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Beacons
Hard8
Geometry, Graph+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Code Permutations
Hard8
Combinatorics, Dynamic programming+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Dinner
Hard8
Graph, Sorting+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
The Pythagorean Theorem
Hard8
Number theory, Math+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
DNA Copy
Hard8
Dynamic programming, Bit manipulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Circle of Debt
Hard8
Dynamic programming, Backtracking+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Different Digits
Hard8
BFS, Dynamic programming+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable

Title	Level	Topics	Solved	Time limit	Memory limit	Judge
Tile CutGiven a grid of W, I, N letters, find the maximum number of disjoint straight or L-shaped triominoes spelling WIN.	Hard8	GraphDynamic programming+2	No attempts yet	1s	128 MB	Judgeable
A Classic Myth: Flatland SuperheroFor each swarm of points, compute the minimum area of a parallelogram that contains all of them, using the rotating calipers method on the convex hull.	Hard8	GeometryDivide and conquer+2	No attempts yet	1s	128 MB	Judgeable
Collateral CleanupGiven a triangulated rectangle, find the lexicographically smallest order to lower triangles straight down so no placed piece blocks a later one.	Hard8	GeometryTopological sort+2	No attempts yet	3s	128 MB	Judgeable
LatticeLandOn a 64x64 grid with up to 6 segment walls, find the fewest moves for a point that changes one velocity component per cell to travel from start to goal and stop there.	Hard8	BFSGraph+2	No attempts yet	2s	128 MB	Judgeable
LocksmithGiven up to three axis-aligned polygonal pieces that interlock without overlapping in area, count how many pieces can be separated by sliding pieces (translation only, no overlap) until a straight line splits that piece from the rest.	Hard8	GeometrySimulation+2	No attempts yet	1s	128 MB	Judgeable
Zombie SwallowsFor each of up to 30 swallows, decide whether some subset of up to 150 insect weights sums to a value in the range [Cmin, Cmax].	Hard8	Dynamic programmingBit manipulation+2	No attempts yet	1s	128 MB	Judgeable
This Can't Go On ForeverFor each modulus m up to 2^24, output the length of the Pisano period of the Fibonacci sequence modulo m.	Hard8	Number theoryMath+2	No attempts yet	1s	128 MB	Judgeable
Spare the Ewoks!Given an m by n grid with blocked cells, choose up to three non-overlapping axis-aligned rectangles to maximize the total covered area.	Hard8	Dynamic programmingPrefix sum+1	No attempts yet	3s	128 MB	Judgeable
Laser ShotFind two different-direction bouncing laser paths from the droid to the Jedi, each with at most n bounces, that minimize the difference of their lengths.	Hard8	GeometryMath+2	No attempts yet	1s	128 MB	Judgeable
Power GridCount the minimum-size edge sets connecting all living quarters to the power station on an 8x8 grid, modulo 1e9.	Hard8	Dynamic programmingGraph+2	No attempts yet	1s	128 MB	Judgeable
Cave CrisisFind the largest radius of a disc that can travel from the origin to the right end of a strip of width w without overlapping any polygon obstacle.	Hard8	GeometryUnion-find+2	No attempts yet	1s	128 MB	Judgeable
Optimal Strategy for the ICPCGiven up to 15 problem solving times, schedule them on three parallel workers within 300 minutes to maximize solved count, then minimize total completion-time penalty, with lexicographically smallest order.	Hard8	Dynamic programmingBit manipulation+2	No attempts yet	1s	128 MB	Judgeable
Repair DepotsPlace at most c depots anywhere in the plane to minimize the largest distance from any of n bots (n at most 16) to its nearest depot, and print that distance to six decimals.	Hard8	Binary searchGeometry+2	No attempts yet	1s	128 MB	Judgeable
Missile CommandGiven missiles moving at constant velocity and circular shots that grow then shrink over 2 seconds, find the minimum number of shots needed to neutralize the same missiles and report the battle score.	Hard8	GeometryGreedy+2	No attempts yet	1s	128 MB	Judgeable
Rubik's CubeGiven a scrambled Rubik's Cube as an unfolded net and a sequence of up to 1000 face rotations, output the cube state after applying all rotations.	Hard8	SimulationImplementation+2	No attempts yet	1s	128 MB	Judgeable
Cover UpGiven up to 5000 boards, each with d columns of distinct digits, compute the probability the contestant eventually wins Cover Up, assuming uniform random picks among untried digits in unfinished columns.	Hard8	ProbabilityDynamic programming+2	No attempts yet	1s	128 MB	Judgeable
Coffin TilesFor each n, find the smallest number of tiles whose unordered factor-pair count equals exactly n, or report Too big above 1000000.	Hard8	Number theoryBrute force+2	No attempts yet	1s	128 MB	Judgeable
Operation: Merchant BoorineiGiven moving vessels and a faster sleigh that spends one hour unloading at each, find the minimum time to visit every vessel and return to the start.	Hard8	Dynamic programmingGeometry+2	No attempts yet	1s	128 MB	Judgeable
Honeycomb, Honeycomb, Me Want Honeycomb!Given intact unit-length hexagonal cell walls as line segments, count how many hexagons still have all six of their walls.	Hard8	GeometryHash map+2	No attempts yet	1s	128 MB	Judgeable
Barcode of JudgmentA barcode is a fixed 7x9 grid pattern placed somewhere in a binary image, possibly rotated; find all valid placements and decode the data bits, or report none or ambiguity.	Hard8	StringImplementation+2	No attempts yet	1s	128 MB	Judgeable
FiltrationParse a set of FIR filter equations, evaluate each filter's output stream in dependency order, and print the resulting samples.	Hard8	SimulationImplementation+2	No attempts yet	1s	128 MB	Judgeable
Fill the CrosswordFill a crossword grid with a given word list so every slot holds a listed word exactly once and crossings match; also decide if no solution exists.	Hard8	BacktrackingTrie+2	No attempts yet	1s	128 MB	Judgeable
Core WarsSimulate 8000-cell Redcode MARS with three addressing modes and report which warrior survives or if they tie after 32000 steps.	Hard8	SimulationImplementation+1	No attempts yet	1s	128 MB	Judgeable
Panic RoomGiven a house of rooms with directed doors, intruder positions, and a panic room, find the minimum number of doors to lock so no intruder reaches it, or report impossible.	Hard8	GraphMinimum spanning tree+2	No attempts yet	1s	128 MB	Judgeable
Jetpack Sniper 3000 Fragfest ExtremeFor each of several 10x10 height grids and four 3D points, decide whether a building blocks the segment from you to players A, B, and C.	Hard8	GeometryImplementation+1	No attempts yet	1s	128 MB	Judgeable
As the Crow FliesGiven a network of cities with lat/lon coordinates and flight legs, find the pair whose shortest route (sum of great-circle leg distances) is the largest.	Hard8	GraphShortest path+2	No attempts yet	1s	128 MB	Judgeable
The Mark of a WizardOn a small DAG, find the shortest path from A to F and the fewest intersections to mark so that following marks still guarantees the shortest time.	Hard8	GraphShortest path+2	No attempts yet	1s	128 MB	Judgeable
Su-domino-kuComplete a 9x9 Sudoku grid in which 36 dominoes cover the empty cells and every distinct digit pair appears as exactly one domino.	Hard8	BacktrackingDFS+2	No attempts yet	2s	128 MB	Judgeable
Top ThisGiven three red tetromino-like pieces and three blue ones, print the row-major first filled cell shape that both sets can tile inside a 6x6 grid.	Hard8	BacktrackingBrute force+2	No attempts yet	1s	128 MB	Judgeable
Quick SearchGiven a small graph and k officers all starting at A, find the minimum time for the officers to jointly visit every node, where each officer walks a path.	Hard8	GraphDynamic programming+1	No attempts yet	1s	128 MB	Judgeable
Line & Circle MazeBuild a graph from intersections of line segments and circles, then report the longest shortest-path distance between any two connected junctions.	Hard8	GeometryGraph+2	No attempts yet	1s	128 MB	Judgeable
SlinkSolve a Slink (all-numbered Slitherlink) puzzle by repeatedly applying twelve local deduction rules, then print the resulting loop as ASCII art.	Hard8	SimulationImplementation+2	No attempts yet	1s	128 MB	Judgeable
Jump, Lizard!Find the maximum number of lizards that can escape the grid by jumping between pillars within Manhattan distance D, where each pillar limits the number of leaps leaving it.	Hard8	GraphShortest path+2	No attempts yet	1s	128 MB	Judgeable
Ink BlotsGiven up to 100 circles that pairwise either miss or cross at two points, count the connected white regions they carve out of the plane.	Hard8	GeometryGraph+2	No attempts yet	1s	128 MB	Judgeable
Bright BraceletArrange all octagons in a cycle so adjacent edges match in color, minimizing the total brightness at the joints.	Hard8	BacktrackingBrute force+2	No attempts yet	1s	128 MB	Judgeable
Fax RegionsGiven the width and run length encoding of a huge fax image, count the connected dark regions using 4-directional adjacency without expanding individual pixels.	Hard8	SimulationImplementation+2	No attempts yet	1s	128 MB	Judgeable
Hilbert CurveCount how many points the n-th Hilbert curve shares with a given horizontal segment whose endpoints are grid multiples of 1/2^n.	Hard8	RecursionDivide and conquer+2	No attempts yet	1s	128 MB	Judgeable
Split WindowsGiven a preorder traversal of a split tree, draw the minimum-sized grid whose boundaries match the layout, applying proportional rounding at each split.	Hard8	TreeRecursion+2	No attempts yet	1s	128 MB	Judgeable
Edge DetectionGiven an image as run-length encoded runs, set each output pixel to the largest absolute difference from its 8 neighbors, and emit the result as runs.	Hard8	SimulationImplementation+2	No attempts yet	1s	128 MB	Judgeable
The DoorsGiven up to 18 vertical walls, each with two doorways, find the shortest path from (0,5) to (10,5) inside a 10x10 square without crossing any solid segment.	Hard8	GeometryGraph+2	No attempts yet	1s	128 MB	Judgeable
FunhouseGiven a walled floor plan, choose rooms covering the least total area so that every entrance-to-exit route passes through a chosen room.	Hard8	GraphShortest path+2	No attempts yet	1s	128 MB	Judgeable
Grimm's ConjectureAssign to each number in a composite interval a distinct prime divisor, choosing the lexicographically smallest assignment, for many test cases with H up to 10^10.	Hard8	Number theoryMath+1	No attempts yet	2s	128 MB	Judgeable
Stained GlassGiven up to 8 polyomino-like ASCII piece silhouettes, each flippable horizontally, decide whether translations of them exactly tile the hole silhouette.	Hard8	BacktrackingBrute force+2	No attempts yet	1s	128 MB	Judgeable
Selling CellsCompute the fraction of a large circle covered by at least one of up to 24 smaller circles whose centers lie outside each other's coverage.	Hard8	GeometryMath+1	No attempts yet	2s	128 MB	Judgeable
Word LadderGiven a vocabulary, find the longest shortest path (number of words) between any two words where a move changes, adds, or removes one letter.	Hard8	GraphBFS+2	No attempts yet	1s	128 MB	Judgeable
Out of SightGiven a walled grid, your start, and the step-by-step routes of several robots, find the maximum number of turns you can survive without any robot seeing you along a row or column.	Hard8	BFSSimulation+2	No attempts yet	1s	128 MB	Judgeable
Crosswords InsiderGiven a list of words and a crossword grid template, decide whether each word can fill one run of empty cells and output the lexicographically smallest filled grid.	Hard8	BacktrackingSimulation+2	No attempts yet	1s	128 MB	Judgeable
Doors and PenguinsGiven axis-parallel rectangles labeled Doors or Penguins, decide whether one straight line avoiding all rectangles can separate the two groups.	Hard8	GeometryDivide and conquer+2	No attempts yet	1s	128 MB	Judgeable
Zoned OutSimulate clerks who union incoming forms with all their past outputs, apply checks and erasures, and report the final version clerk 0 sends.	Hard8	SimulationGraph+2	No attempts yet	1s	128 MB	Judgeable
GHOSTGiven a GHOST position and dictionary, decide whether the computer should challenge, add the smallest safe letter, or bluff.	Hard8	Game theoryTrie+2	No attempts yet	1s	128 MB	Judgeable
Line of SightGiven a house segment, a property-line segment, and horizontal obstruction segments, find the length of the longest continuous stretch of the property line from which the whole house is visible.	Hard8	GeometrySorting+2	No attempts yet	1s	128 MB	Judgeable
Unhappy NumbersCount numbers in [lo, hi] that never reach 1 under the digit-square-sum map; bounds go up to 1e18 so answers need digit DP over precomputed unhappy states.	Hard8	MathDynamic programming+2	No attempts yet	1s	128 MB	Judgeable
WallsChoose the minimum number of odd-coordinate vertical or horizontal walls so that every segment between two stations is crossed by at least one wall.	Hard8	GeometryGreedy+2	No attempts yet	5s	128 MB	Judgeable
CosmoCraftDecide how to split income among workers, facilities, and army each turn so all attacks are survived and the final army is as large as possible.	Hard8	GreedySimulation+2	No attempts yet	1s	128 MB	Judgeable
The Red GemFor each test case, find the fraction of a circular platform's circumference from which an entire red disk is visible without any orange disk blocking the line of sight.	Hard8	GeometryIntervals+2	No attempts yet	1s	128 MB	Judgeable
The Worm in the AppleGiven a convex polyhedron as the hull of n points, answer queries for the distance from an interior point to the surface.	Hard8	GeometryBinary search+1	No attempts yet	15s	128 MB	Judgeable
Sloppy SortGiven a possibly inconsistent comparison function as an n by n table, find the permutation of 0 to n-1 with the fewest inversions, breaking ties by the lexicographically smallest one.	Hard8	Dynamic programmingBit manipulation+2	No attempts yet	3s	128 MB	Judgeable
Function OverloadingParse nested overloaded function calls; for each, determine whether resolution is unique, impossible, or ambiguous, counting ambiguity cases up to 1000.	Hard8	Dynamic programmingImplementation+2	No attempts yet	2s	128 MB	Judgeable
Catching Shade in FlatlandGiven N disjoint circles inside a park, track a ray from a sun rotating around the origin and report the maximum total chord length cut through all trees over 1440 one-minute samples.	Hard8	GeometryMath+2	No attempts yet	1s	128 MB	Judgeable
Supply MissionFind the minimum total time for a helicopter to visit every moving submarine in any order, land one hour at each, and return to base.	Hard8	Brute forceGeometry+2	No attempts yet	2s	128 MB	Judgeable
Task SchedulingAssign each task the earliest possible start minute so that all minimum-gap and bounded-window constraints between pairs of tasks hold, or report impossibility.	Hard8	Shortest pathGraph+2	No attempts yet	1s	128 MB	Judgeable
SoccerGiven a partial soccer schedule with at most 12 unplayed matches, find the best and worst final rank each team can still achieve. Ties share the same position.	Hard8	Brute forceImplementation+2	No attempts yet	2s	128 MB	Judgeable
PapaGiven consistent family relations, infer spouses, parents, children, and sexes, then answer yes, no, or unknown for kinship queries like niece or grandfather.	Hard8	GraphUnion-find+2	No attempts yet	1s	128 MB	Judgeable
WhenExecute a complete When program, an event-driven language with simultaneous Set assignments and a rotating active-clause scheduler, and print its output.	Hard8	SimulationImplementation+2	No attempts yet	1s	128 MB	Judgeable
National TreasuresGiven a grid of artifacts with bitmask critical points and cells already holding guards, replace some artifacts with hired guards so every remaining artifact has a guard on each of its critical points, minimizing hires.	Hard8	GreedyMinimum spanning tree+2	No attempts yet	1s	128 MB	Judgeable
Pattern MatchingDecide whether digit sequences match patterns where digits match exactly and * and # stand for even and odd counts of arbitrary digits.	Hard8	Dynamic programmingString matching	No attempts yet	1s	128 MB	Judgeable
Moving SticksGiven an arithmetic equation written in seven-segment digits, move exactly n segments so the equation becomes true, choosing the lexicographically smallest solution.	Hard8	Brute forceImplementation+2	No attempts yet	1s	128 MB	Judgeable
A-to-ZGiven a word dictionary, for each pair of letters find the minimum total width of a word chain where consecutive words overlap by at least two letters, and the first starts with C1, the last ends with C2.	Hard8	GraphShortest path+2	No attempts yet	1s	128 MB	Judgeable
Alpha of Degree kGiven a dictionary, answer queries asking for the shortest chain from word s to word t where each step shares a suffix-prefix overlap of length at least k, with a cap on chain length.	Hard8	GraphBFS+2	No attempts yet	1s	128 MB	Judgeable
Queue SortGiven a permutation in a queue and two auxiliary stacks, find the minimum number of bulk transfer operations to sort the queue into ascending order.	Hard8	BFSSimulation+2	No attempts yet	1s	128 MB	Judgeable
Weaker than PlannedGiven candidate plaintext words and a ciphertext message, recover the plaintext under one unknown letter-pair substitution, or report that it is not unique.	Hard8	BacktrackingString+2	No attempts yet	1s	128 MB	Judgeable
Driving an Icosahedral RoverGiven a triangular grid and an icosahedron that rolls face-over-edge, find the fewest rolls to reach trigon (x, y) with face n on the bottom.	Hard8	BFSSimulation+2	No attempts yet	3s	128 MB	Judgeable
City MergerGiven up to 14 uppercase city names, find the length of the shortest string that contains every name as a consecutive substring, allowing overlaps.	Hard8	Dynamic programmingBit manipulation+2	No attempts yet	2s	128 MB	Judgeable
Captain Q's TreasureGiven a grid with at most 15 digit cells, each stating how many chests lie in its 3x3 neighborhood, find the minimum number of chests consistent with all digits.	Hard8	BacktrackingBrute force+2	No attempts yet	3s	128 MB	Judgeable
ASCII ExpressionParse a multi-line monospace arithmetic expression into its syntax tree, then evaluate it modulo the prime 2011 with modular inverses for fractions.	Hard8	ImplementationRecursion+2	No attempts yet	1s	128 MB	Judgeable
Laser Beam ReflectionsWith up to five mirrors and fewer than six reflections on the shortest path, compute the length of the generator-to-target path, rounding to three decimals.	Hard8	GeometryBrute force+1	No attempts yet	2s	128 MB	Judgeable
Tighten Up!Given a polygonal string between two holes and a set of pins, compute the length of the taut chain that wraps around the pins when pulled tight.	Hard8	GeometryGreedy+2	No attempts yet	1s	128 MB	Judgeable
Roll a Big BallFind the largest radius of a ball that rolls along a straight course without hitting any axis-aligned rectangular block.	Hard8	GeometryBinary search+2	No attempts yet	1s	128 MB	Judgeable
Dr. Podboq, or: How We Became AsymmetricRead a binary tree of cells, define each cell's left-right similarity by shared subtree shapes up to child swaps, then reorder children by asymmetry and print the normalized tree.	Hard8	TreeDFS+2	No attempts yet	1s	128 MB	Judgeable
Hexerpents of HexwampGiven a chain of up to 8 hexagon sections on a hex grid with rocks, find the minimum number of simultaneous legal moves to bring the head to a goal cell.	Hard8	BFSSimulation+2	No attempts yet	10s	128 MB	Judgeable
Water TankSimulate water filling a 100 cm tank divided by partition boards of distinct heights, with faucets pouring into regions, and report the exact water level at given positions and times as integers or reduced fractions.	Hard8	SimulationSorting+2	No attempts yet	1s	128 MB	Judgeable
Name the CrossingGiven named crossings of orthogonal streets, infer an equal-strength and stronger-than relation between streets, then answer whether each queried crossing name is valid.	Hard8	GraphUnion-find+2	No attempts yet	1s	128 MB	Judgeable
Eco-drivingFind a route from junction 1 to J with total length at most D that minimizes the largest turn angle at any intermediate junction, and print that angle.	Hard8	GraphBinary search+2	No attempts yet	1s	128 MB	Judgeable
Galactic WarlordsGiven N lines in the plane, find the minimum number of extra lines to add so that the arrangement has at least W unbounded regions (sectors of infinite area).	Hard8	GeometryCombinatorics+2	No attempts yet	1s	128 MB	Judgeable
InfiltrationGiven an encrypted line using a one-to-one letter substitution, recover the plaintext if exactly one consistent mapping exists using a subset of twelve known words that covers all distinct cipher letters.	Hard8	StringHash map+2	No attempts yet	1s	128 MB	Judgeable
Private SpaceChoose the smallest widest row width X (at most 12) so that all groups fit into triangular rows of widths X down to 1, keeping one empty seat between neighboring groups in a row.	Hard8	Dynamic programmingBit manipulation+2	No attempts yet	1s	128 MB	Judgeable
Enemy DivisionDivide soldiers into the fewest groups so that each soldier shares a group with at most one enemy, where every soldier has at most 3 enemies.	Hard8	GraphGreedy+2	No attempts yet	1s	128 MB	Judgeable
ConnectionPlace two vertex-disjoint grid paths on an N x M lattice, one joining A1 to A2 and the other B1 to B2, to minimize the total number of unit segments.	Hard8	GraphShortest path+2	No attempts yet	1s	128 MB	Judgeable
Borg BoogieGiven a connected undirected graph and a fixed walk, find the probability that a random-walking sentry never collides or swaps with the captain during the walk.	Hard8	Dynamic programmingProbability+2	No attempts yet	1s	128 MB	Judgeable
Polyomino PowersGiven a polyomino on a grid up to 10x10, find the smallest k in 2..5 such that the shape is tiled by k translated copies of one smaller polyomino, or report none.	Hard8	Brute forceBacktracking+2	No attempts yet	1s	128 MB	Judgeable
StatisticiansGiven a grid of counts, take the median of the mean densities over all axis-aligned subrectangles whose area lies in [a,b].	Hard8	Prefix sumBinary search+1	No attempts yet	1s	128 MB	Judgeable
Speedy EscapeOn a weighted graph with a speed-160 pursuer starting at p, find the smallest top speed so the brothers can reach any exit before being caught on any route.	Hard8	GraphShortest path+2	No attempts yet	1s	128 MB	Judgeable
Flight PlanningGiven a tree, delete one edge and add one edge so the result is a tree with the smallest possible diameter.	Hard8	TreeDFS+2	No attempts yet	1s	128 MB	Judgeable
BeaconsGiven point beacons and circular mountain peaks, build the visibility graph where a segment is blocked if it crosses a circle, then count the connected components minus one.	Hard8	GeometryGraph+2	No attempts yet	2s	128 MB	Judgeable
Code PermutationsCount permutations of 1..N whose order (LCM of cycle lengths) equals K, modulo 2^31-1.	Hard8	CombinatoricsDynamic programming+2	No attempts yet	2s	128 MB	Judgeable
DinnerGiven a complete graph on n vertices with edge years (default 2008), find the smallest year Y such that vertices split into two parts of size at most 2n/3, one with all edges before Y, the other with all edges at or after Y.	Hard8	GraphSorting+2	No attempts yet	1s	128 MB	Judgeable
The Pythagorean TheoremGiven n, count ordered triples (a,b,c) with 1<=a<=b<=n-1 and c<=n-1 such that a^2+b^2 is congruent to c^2 modulo n.	Hard8	Number theoryMath+2	No attempts yet	1s	128 MB	Judgeable
DNA CopyGiven a source string S of length at most 18, find the minimum number of copy operations (each taking a contiguous substring of S or of the already-built target, optionally reversed) needed to assemble T.	Hard8	Dynamic programmingBit manipulation+2	No attempts yet	1s	128 MB	Judgeable
Circle of DebtGiven three people's debts and the exact bills and coins each holds, find the minimum number of pieces that must change hands to settle all debts.	Hard8	Dynamic programmingBacktracking+2	No attempts yet	1s	128 MB	Judgeable
Different DigitsFor each n below 65536, find the smallest positive multiple of n whose decimal form uses the fewest distinct digits.	Hard8	BFSDynamic programming+2	No attempts yet	1s	128 MB	Judgeable