Problems

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Total results29,423 problems

Harvesting a Farm
Hard8
Graph, BFS+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Rectangular Painting
Hard8
Tree, DFS+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Sightseeing
Hard8
Binary search, Graph+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Minimum-Cost Prefix-Free Language
Hard8
Dynamic programming, Greedy+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
New Island
Hard8
Graph, Shortest path+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Sharif Super Computer
Hard8
Brute force, Backtracking+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Circle Artwork
Hard8
Geometry, Brute force+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Crazy Bits
Hard8
BFS, Simulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Nurikabe
Hard8
Backtracking, DFS+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Against Mammoths
Hard8
Binary search, Greedy+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Triangle Pizza
Hard8
Backtracking, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Triangles and Quadrangle
Hard8
Geometry, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Share the Cakes
Hard8
Geometry, Binary search+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Quelling Blade
Hard8
Greedy, DFS+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Ball Machine
Hard8
Tree, Simulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Brunhilda's Birthday
Hard8
Dynamic programming, Number theory+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Tracks in the Snow
Hard8
Graph, Greedy+2
No attempts yet
Time limit
2s
Memory limit
1300 MB
Judgeable
Intervals
Hard8
Greedy, Sorting+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Timetable
Hard8
Graph, Shortest path+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Optimal Programs
Hard8
Brute force, DFS+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Video Surveillance
Hard8
Geometry, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Ouroboros Snake
Hard8
Combinatorics, Bit manipulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Fold-up Patterns
Hard8
Geometry, Graph+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Append
Hard8
String, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Tin Cutter
Hard8
Geometry, Graph+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
L-system Substring
Hard8
String, Simulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Intervals
Hard8
Geometry, Sorting+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Strictly Inscribed Similar Triangles
Hard8
Geometry, Math+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Xenosemantics
Hard8
String, Hash map+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Doing Windows
Hard8
Geometry, Math+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Stars
Hard8
Geometry, Hash map+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Hexagon
Hard8
Backtracking, Brute force+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Ships
Hard8
Backtracking, Brute force+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Perfect Hash
Hard8
Hash map, Math+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Hotel Booking
Hard8
Graph, Shortest path+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Frequent Values
Hard8
Segment tree, Divide and conquer+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Fold
Hard8
Dynamic programming, Recursion+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Addition Chains
Hard8
DFS, Backtracking+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Lisa the Ladybug and the Broken Calculator
Hard8
BFS, Implementation+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Simon the Spider
Hard8
Minimum spanning tree, Graph+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Simple Polygon
Hard8
Geometry, Sorting+2
No attempts yet
Time limit
10s
Memory limit
128 MB
Judgeable
Domino Tiling
Hard8
Backtracking, Dynamic programming+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
No Smoking
Hard8
Geometry, Union-find+2
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
Pyramid Guards
Hard8
Geometry, Math+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Letter Lies
Hard8
Dynamic programming, Graph+2
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
Robotic Rails
Hard8
Graph, Geometry+2
No attempts yet
Time limit
10s
Memory limit
128 MB
Judgeable
International Collegiate Programming Contest
Hard8
Simulation, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Careful Declaration
Hard8
Dynamic programming, String+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Tree Insertions
Hard8
Tree, Combinatorics+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Catch the Bus!
Hard8
Shortest path, Graph+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Money Money Money, Must Be Funny
Hard8
Dynamic programming, Greedy+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
All Friends
Hard8
Graph, Backtracking+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Board Game
Hard8
Game theory, Graph+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Failing Roads
Hard8
Tree, Dynamic programming+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Go Endgame
Hard8
Dynamic programming, Game theory+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Agents
Hard8
Graph, DFS+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Boatherds
Hard8
Divide and conquer, Tree+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
God of the Vile Baskers
Hard8
String, Sliding window+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Base Numbers
Hard8
Dynamic programming, Combinatorics+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Paper Cutting
Hard8
Math, Greedy+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Easter Holidays Ski Journey
Hard8
Binary search, Shortest path+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Subway Planning
Hard8
Geometry, Greedy+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Exploding CPU
Hard8
Number theory, Brute force+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Quantum
Hard8
Graph, Shortest path+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Request for Permission
Hard8
Geometry, Brute force+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Connected Gheeves
Hard8
Geometry, Binary search+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Rotating Scoreboard
Hard8
Geometry, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
ACM Underground
Hard8
Geometry, Graph+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Software Company
Hard8
Binary search, Greedy+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Transforming Comets
Hard8
String matching, Geometry+2
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
The Winds of War
Hard8
Geometry, Sorting+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Switch
Hard8
Dynamic programming, Greedy+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Fixing Disks
Hard8
Dynamic programming, Stack+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Nutrient Tree
Hard8
Tree, Dynamic programming+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Beware the Geoducks
Hard8
Implementation, Simulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
A Weighty Problem
Hard8
Dynamic programming, Greedy+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Gerrymandering
Hard8
Dynamic programming, Prefix sum+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Origin of Life
Hard8
BFS, Simulation+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Jengaism
Hard8
Geometry, Simulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Orko
Hard8
Game theory, Backtracking+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Concentration Cards
Hard8
Math, Geometry+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Cube
Hard8
Graph, DFS+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Post's Correspondence Problem
Hard8
BFS, String+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Partitions
Hard8
Dynamic programming, Combinatorics+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Ransom Note
Hard8
Dynamic programming, String+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
The Game of 31
Hard8
Game theory, Dynamic programming+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Manelzuma's Revenge
Hard8
Recursion, Divide and conquer
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Grading
Hard8
Dynamic programming, Number theory+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Snails
Hard8
Geometry, Simulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Railway Connection
Hard8
Graph, Shortest path+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Chain-Confined Path
Hard8
Geometry, Shortest path+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Generic Poker
Hard8
Combinatorics, Brute force+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
A Strip of Land
Hard8
Sliding window, Matrix+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Cow Ski Area
Hard8
Graph, DFS+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Clouds
Hard8
Geometry, Sorting+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Sweets
Hard8
Dynamic programming, Prefix sum+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Bugs Integrated, Inc.
Hard8
Dynamic programming, Bit manipulation
No attempts yet
Time limit
15s
Memory limit
128 MB
Judgeable
Word Counting
Hard8
String matching, Trie+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Circle
Hard8
Math, Geometry+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Sevens, Twos and Zeros
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
Harvesting a FarmGiven a grid of crops 1 and 2 with no 2x2 checkerboard, find the minimum number of cutter changes (including the first attachment) to harvest every cell, moving freely only on matching or empty cells.	Hard8	GraphBFS+2	No attempts yet	1s	128 MB	Judgeable
Rectangular PaintingGiven a nesting tree of rectangles and photo leaf sizes, orient each sibling group horizontally or vertically to minimize the root rectangle area.	Hard8	TreeDFS+2	No attempts yet	1s	128 MB	Judgeable
SightseeingTwo people walk from a start to a goal, one on B-edges only and one on W-edges only, each able to wait a day; minimize the maximum squared distance between them over nights.	Hard8	Binary searchGraph+2	No attempts yet	1s	128 MB	Judgeable
Minimum-Cost Prefix-Free LanguageGiven n and d character costs, find the minimum total cost of a prefix-free set of exactly n words; multiple test cases end with 0 0.	Hard8	Dynamic programmingGreedy+2	No attempts yet	1s	128 MB	Judgeable
New IslandGiven a graph whose edge i costs 2^i, delete the cheapest set of edges so the graph stays connected and every pairwise distance at most doubles.	Hard8	GraphShortest path+2	No attempts yet	1s	128 MB	Judgeable
Sharif Super ComputerChoose distinct positive slave heights between 0 and a top master height H so that all red cable lengths match exactly and every slave pair distance is an allowed blue length, minimizing the output sequence lexicographically.	Hard8	Brute forceBacktracking+2	No attempts yet	1s	128 MB	Judgeable
Circle ArtworkGiven up to 100 colored points, count how many colors have a circle through two of their points that contains no point of another color.	Hard8	GeometryBrute force+2	No attempts yet	1s	128 MB	Judgeable
Crazy BitsGiven initial and target 12-bit register values, find the minimum number of adjacent bit swaps (within and between registers) to transform one configuration into the other, or report impossibility.	Hard8	BFSSimulation+2	No attempts yet	1s	128 MB	Judgeable
NurikabeSolve Nurikabe puzzles on grids up to 9x9 by coloring cells black or white so all six connectivity and counting rules hold.	Hard8	BacktrackingDFS+2	No attempts yet	1s	128 MB	Judgeable
Against MammothsAssign each human planet to at most one alien planet and pick a launch year so the fleet wins on arrival, minimizing the year the last alien falls.	Hard8	Binary searchGreedy+2	No attempts yet	1s	128 MB	Judgeable
Triangle PizzaCount the number of distinct connected polyiamonds with N cells, where shapes that match under rotation or translation count as one and reflections are distinct.	Hard8	BacktrackingImplementation+2	No attempts yet	1s	128 MB	Judgeable
Triangles and QuadrangleGiven two triangles and a quadrangle, decide whether the triangles can be joined along a full edge, without overlap, to form the quadrangle up to translation, rotation, and reflection.	Hard8	GeometryImplementation+2	No attempts yet	1s	128 MB	Judgeable
Share the CakesGiven two disjoint convex polygons, find the single line that simultaneously bisects the area of both, and output its slope and intercept scaled by 1e6.	Hard8	GeometryBinary search+2	No attempts yet	2s	128 MB	Judgeable
Quelling BladeGiven a tree of weapon prerequisites with costs and benefits, find a buying order that reaches the root in minimum time while maximizing the sum over time of owned benefit.	Hard8	GreedyDFS+2	No attempts yet	1s	128 MB	Judgeable
Ball MachineSimulate a ball machine on a rooted tree: dropping balls follows a fixed priority path, and removing a ball makes balls above roll down; report resting node or number of moves.	Hard8	TreeSimulation+2	No attempts yet	1s	128 MB	Judgeable
Brunhilda's BirthdayFor each n, find the minimum number of calls of primes from a given set that reduce n to 0 by replacing n with p*floor(n/p), or report infinity.	Hard8	Dynamic programmingNumber theory+2	No attempts yet	1s	256 MB	Judgeable
Tracks in the SnowGiven a grid where each tracked cell shows the most recent animal (R or F), find the minimum number of animals that crossed from the top-left to the bottom-right.	Hard8	GraphGreedy+2	No attempts yet	2s	1300 MB	Judgeable
IntervalsGiven n integer intervals each needing at least c_i chosen points inside it, find the smallest set of integers satisfying all requirements.	Hard8	GreedySorting+2	No attempts yet	1s	128 MB	Judgeable
TimetableGiven a network of direct train legs, compute all Pareto-optimal journeys from city 1 to city n, where one journey dominates another if it departs no earlier and arrives no later.	Hard8	GraphShortest path+2	No attempts yet	1s	128 MB	Judgeable
Optimal ProgramsFor each set of input/output pairs, find the shortest stack-machine program of at most 10 commands made of ADD, SUB, MUL, DIV, and DUP, with lexicographically smallest ties.	Hard8	Brute forceDFS+2	No attempts yet	1s	128 MB	Judgeable
Video SurveillanceGiven a rectilinear simple polygon, decide whether one point exists from which the whole interior is visible.	Hard8	GeometryImplementation+2	No attempts yet	1s	128 MB	Judgeable
Ouroboros SnakeGiven n and k, find the n-bit number starting at position k in the de Bruijn circle built from the smallest Ouroboros number of size n.	Hard8	CombinatoricsBit manipulation+2	No attempts yet	1s	128 MB	Judgeable
Fold-up PatternsGiven a planar net of unit squares with specified fold directions on shared edges, determine whether folding yields a closed surface of a solid and report its volume.	Hard8	GeometryGraph+2	No attempts yet	1s	128 MB	Judgeable
AppendGiven an LZ-style encoding as a list of (back-reference, length) pairs, count how many prefix positions split it into two valid non-empty encodings whose concatenation reproduces the original string.	Hard8	StringImplementation+2	No attempts yet	1s	128 MB	Judgeable
Tin CutterGiven up to 100 axis-parallel cuts inside a plate, count how many holes (closed regions not touching the plate border) remain after all cuts are made.	Hard8	GeometryGraph+2	No attempts yet	1s	128 MB	Judgeable
L-system SubstringGiven a D0L system over {a,b} and a query z, decide whether z appears as a contiguous substring of some word derivable from the start word.	Hard8	StringSimulation+2	No attempts yet	1s	128 MB	Judgeable
IntervalsGiven a point light above the x-axis and non-overlapping circular pipes below it, find the shadowed intervals on the x-axis, sorted and rounded to two decimals.	Hard8	GeometrySorting+2	No attempts yet	1s	128 MB	Judgeable
Strictly Inscribed Similar TrianglesFor each triangle and angle theta, count how many strictly inscribed triangles similar in order to the given triangle exist with a chosen edge at that angle.	Hard8	GeometryMath+2	No attempts yet	1s	128 MB	Judgeable
XenosemanticsFind words over lowercase letters delimited by varying spacer letters in a bit stream, then report the distinct true words that repeat and overlap another true word.	Hard8	StringHash map+2	No attempts yet	1s	128 MB	Judgeable
Doing WindowsGiven a screen and four windows with fixed aspect ratios, decide whether the windows can be resized and placed to tile the screen with no gaps or overlaps.	Hard8	GeometryMath+2	No attempts yet	1s	128 MB	Judgeable
StarsCount and find the brightest occurrence of each constellation pattern as a direct similarity transform of integer points within a star map.	Hard8	GeometryHash map+2	No attempts yet	1s	128 MB	Judgeable
HexagonPlace 19 of 27 hexagonal pieces on a 19-cell board so that the total of all 15 monochromatic row scores is as large as possible.	Hard8	BacktrackingBrute force+2	No attempts yet	1s	128 MB	Judgeable
ShipsGiven partial knowledge of seven non-overlapping tetromino ships on a grid, decide if all 28 ship squares can be uncovered with at most one miss against every consistent arrangement.	Hard8	BacktrackingBrute force+1	No attempts yet	1s	128 MB	Judgeable
Perfect HashFor each line of up to 13 short words, find the smallest positive integer C so the hash floor(C/w) mod n is collision free, and print C after echoing the input line.	Hard8	Hash mapMath+2	No attempts yet	1s	128 MB	Judgeable
Hotel BookingGiven a road network and up to 100 hotel cities, find the minimum number of hotels to book so every driving leg between stays is at most 600 minutes.	Hard8	GraphShortest path+2	No attempts yet	1s	128 MB	Judgeable
Frequent ValuesFor each range query on a sorted array, output how many times the most frequent value occurs inside the range.	Hard8	Segment treeDivide and conquer+1	No attempts yet	1s	128 MB	Judgeable
FoldGiven the sequence of A/V fold directions along an unfolded paper strip, find the minimum number of all-layer folding steps that produce it.	Hard8	Dynamic programmingRecursion+2	No attempts yet	1s	128 MB	Judgeable
Addition ChainsFor each n up to 100, find a shortest addition chain ending at n and print the lexicographically smallest among all shortest ones.	Hard8	DFSBacktracking+2	No attempts yet	1s	256 MB	Judgeable
Lisa the Ladybug and the Broken CalculatorGiven a set of working calculator buttons, find the shortest sequence of presses that leaves target N on a display limited to 0..999.	Hard8	BFSImplementation+2	No attempts yet	2s	128 MB	Judgeable
Simon the SpiderPick a connected spanning subgraph minimizing total edge weight minus twice the heaviest chosen edge, or report that the graph is disconnected.	Hard8	Minimum spanning treeGraph+2	No attempts yet	2s	128 MB	Judgeable
Simple PolygonGiven up to 40,000 points defining a closed polygon, decide whether its edges only meet at shared endpoints (simple) or intersect anywhere (NO).	Hard8	GeometrySorting+2	No attempts yet	10s	128 MB	Judgeable
Domino TilingCover a grid with pre-placed tiles and all given dominoes, then output the lexicographically smallest valid tiling and the count of other tilings.	Hard8	BacktrackingDynamic programming+2	No attempts yet	1s	128 MB	Judgeable
No SmokingGiven up to 200 disjoint rectangles in a town rectangle, decide whether some point in the town lies at distance at least D minus 0.1 from every building.	Hard8	GeometryUnion-find+2	No attempts yet	3s	128 MB	Judgeable
Pyramid GuardsTwo guards walk opposite closed quadrilateral loops on a square pyramid's surface; find the minimum straight-line distance between them while they share a face.	Hard8	GeometryMath+2	No attempts yet	1s	128 MB	Judgeable
Letter LiesCount the number of length-L paths from a greeting sentence to a closing sentence in a directed graph whose successor rules guarantee no sentence repeats.	Hard8	Dynamic programmingGraph+2	No attempts yet	3s	128 MB	Judgeable
Robotic RailsGiven up to 100 line segments in the plane, find the shortest path from a fixed start point and heading to a fixed target point and heading, where turns at intersections may not exceed 90 degrees.	Hard8	GraphGeometry+2	No attempts yet	10s	128 MB	Judgeable
International Collegiate Programming ContestGiven the exact output of a banking simulator, rebuild the canonical input: map each result line to a fixed request and choose the smallest initial balance B that keeps every request valid.	Hard8	SimulationImplementation+2	No attempts yet	1s	128 MB	Judgeable
Careful DeclarationMerge two word sequences into the shortest common supersequence, breaking ties by choosing the lexicographically smallest result.	Hard8	Dynamic programmingString+2	No attempts yet	2s	128 MB	Judgeable
Tree InsertionsCount how many permutations of a given sequence build the same binary search tree; values may repeat and answers need big integers.	Hard8	TreeCombinatorics+2	No attempts yet	1s	128 MB	Judgeable
Catch the Bus!Given bus routes with hourly timetables and two students' start times and stops, find the earliest moment they can meet at any shared stop, considering 2-minute transfer times.	Hard8	Shortest pathGraph+2	No attempts yet	1s	128 MB	Judgeable
Money Money Money, Must Be FunnyGiven limited cash held by a customer and a shopkeeper, find the minimum number of coins and notes that must change hands to settle an exact amount.	Hard8	Dynamic programmingGreedy+1	No attempts yet	1s	256 MB	Judgeable
All FriendsCount the maximal cliques of an undirected graph with up to 128 vertices, reporting "Too many" when the count exceeds 1000.	Hard8	GraphBacktracking+2	No attempts yet	1s	128 MB	Judgeable
Board GameTwo pieces move on a small board with holes; positions cannot repeat, so decide which player wins under optimal play.	Hard8	Game theoryGraph+2	No attempts yet	1s	128 MB	Judgeable
Failing RoadsGiven an expression tree of merge and complement operations, compute the maximum independent set of the resulting graph.	Hard8	TreeDynamic programming+2	No attempts yet	1s	128 MB	Judgeable
Go EndgameGiven starting scores, region values, and sente flags, compute the final scores when Alice and Bob alternately pick regions and respond until all are settled.	Hard8	Dynamic programmingGame theory+2	No attempts yet	1s	128 MB	Judgeable
AgentsGiven a graph of dislikes where at most three agents touch everyone else, decide whether the vertices 3-color into at most three independent sets and output the lexicographically smallest coloring.	Hard8	GraphDFS+2	No attempts yet	1s	128 MB	Judgeable
BoatherdsGiven a weighted tree and up to 100 queries, decide for each target value whether some pair of vertices has a path cost exactly equal to it.	Hard8	Divide and conquerTree+2	No attempts yet	1s	128 MB	Judgeable
God of the Vile BaskersFind the longest prefix of a string that contains no two substrings with the same multiset of k alphabetic characters, ignoring case.	Hard8	StringSliding window+2	No attempts yet	1s	128 MB	Judgeable
Base NumbersFor each digit string, count the ways to insert parentheses and dashes so it decodes to a valid decimal-encoded number in some base greater than 1.	Hard8	Dynamic programmingCombinatorics+2	No attempts yet	1s	128 MB	Judgeable
Paper CuttingFor each test case, decide whether an A by B grid of C by D cards fits on an E by F sheet in some rotation, then report the minimum number of straight cuts needed to separate the cards.	Hard8	MathGreedy+2	No attempts yet	1s	128 MB	Judgeable
Easter Holidays Ski JourneyFor each resort, find a cycle that goes up by lifts then down by slopes, maximizing the ratio of total slope time to total lift time, and print it as a reduced fraction.	Hard8	Binary searchShortest path+2	No attempts yet	1s	128 MB	Judgeable
Subway PlanningGiven points in the plane and a radius d, cover all points using the fewest rays from the origin, where a ray covers a point if some point on the ray is within distance d.	Hard8	GeometryGreedy+2	No attempts yet	1s	128 MB	Judgeable
Exploding CPUCount integers in a range that factor as p1p2...pn (n>=3) where consecutive primes follow p_i = Ap_{i-1}+B, starting from p_0=1.	Hard8	Number theoryBrute force+2	No attempts yet	1s	128 MB	Judgeable
QuantumGiven up to 32 quantum operations on length-L bit words and their costs, find the minimum cost to transform each source word into a target word, or report it impossible.	Hard8	GraphShortest path+2	No attempts yet	1s	128 MB	Judgeable
Request for PermissionGiven a convex country, M nearest-station Voronoi cells, and a straight flight segment outside the border, list the cells the flight crosses in order.	Hard8	GeometryBrute force+2	No attempts yet	1s	128 MB	Judgeable
Connected GheevesGiven two convex funnel-shaped containers joined at the bottom, find the water level reached after pouring a given area of water, capped at the lower rim.	Hard8	GeometryBinary search+2	No attempts yet	1s	128 MB	Judgeable
Rotating ScoreboardGiven a simple polygon, decide whether some interior point sees every boundary point, which happens exactly when the polygon's kernel is nonempty.	Hard8	GeometryImplementation+2	No attempts yet	1s	128 MB	Judgeable
ACM UndergroundGiven metro lines, policemen on them, and two points, decide whether the destination is reachable without ever being checked, where checks happen at line changes and at non-intersection spots on lines.	Hard8	GeometryGraph+2	No attempts yet	1s	128 MB	Judgeable
Software CompanyAssign m subprojects of each of two projects to n employees, who work sequentially, to minimize the largest total working time.	Hard8	Binary searchGreedy+2	No attempts yet	1s	128 MB	Judgeable
Transforming CometsGiven two cyclic sequences of integer points, decide whether one is a rotation, uniform positive scaling, and translation of the other, and report the matching cyclic offset.	Hard8	String matchingGeometry+2	No attempts yet	5s	512 MB	Judgeable
The Winds of WarChoose a convex net containing the origin that covers as many enemy units as possible while covering as few friendly ones, and report the maximum difference.	Hard8	GeometrySorting+2	No attempts yet	2s	512 MB	Judgeable
SwitchGiven a row of K lights with no four consecutive on, find the fewest off-to-on switches needed so that all lights end up off, given the automatic clearing of any block of four or more on.	Hard8	Dynamic programmingGreedy+1	No attempts yet	2s	512 MB	Judgeable
Fixing DisksGiven a master stack and your own stack of N labeled disks, use three limited reorder moves on the top K disks to remove disks cheaply; minimize total cost under a removal-order constraint.	Hard8	Dynamic programmingStack+2	No attempts yet	2s	512 MB	Judgeable
Nutrient TreeGiven a binary tree whose leaves produce nutrients and whose edges have capacity (1+w)^2 after spending w agents, distribute X agents over edges and leaves to maximize the flow reaching the root.	Hard8	TreeDynamic programming+2	No attempts yet	2s	512 MB	Judgeable
Beware the GeoducksGiven two fixed walking routes on a weighted graph, decide whether the two travelers ever occupy the same point within t seconds, accounting for nodes with geoducks that make a traveler vanish.	Hard8	ImplementationSimulation+2	No attempts yet	1s	128 MB	Judgeable
A Weighty ProblemChoose which coins to hand over for a purchase so that the total weight of unspent coins plus the store's greedy change is minimized.	Hard8	Dynamic programmingGreedy+2	No attempts yet	1s	128 MB	Judgeable
GerrymanderingMerge adjacent ridings into blocks so Party 1 strictly wins a majority of the remaining ridings, minimizing the number of merges.	Hard8	Dynamic programmingPrefix sum+2	No attempts yet	1s	128 MB	Judgeable
Origin of LifeGiven a 2D cellular automaton with parameters a, b, c, find the smallest number of steps from a Garden of Eden (a state with no predecessor) to the given state, or -1 if impossible.	Hard8	BFSSimulation+2	No attempts yet	1s	1024 MB	Judgeable
JengaismSimulate Jenga moves (remove a block, place it on top) and report when any structure topples because its center of gravity leaves the convex hull of its supports.	Hard8	GeometrySimulation+2	No attempts yet	1s	128 MB	Judgeable
OrkoGiven ten cards for player A and the rest for B, compute how many of the ten rounds A wins when both play optimally, with A leading first.	Hard8	Game theoryBacktracking+2	No attempts yet	1s	128 MB	Judgeable
Concentration CardsGiven N cards of size W by H that can each be rotated, tile a filled rectangle with them and find the smallest possible perimeter.	Hard8	MathGeometry+2	No attempts yet	1s	128 MB	Judgeable
CubeGiven an n by n by n grid of letters, decide whether the connected same-letter pieces can be pulled apart without cutting, meaning no single piece separates the cube.	Hard8	GraphDFS+2	No attempts yet	1s	128 MB	Judgeable
Post's Correspondence ProblemFind the shortest, lexicographically smallest index sequence whose A-concatenation equals its B-concatenation, under k < m.	Hard8	BFSString+2	No attempts yet	1s	128 MB	Judgeable
PartitionsGiven k and a, output the a-th partition of k in lexicographic order, or Too big when a exceeds the partition count.	Hard8	Dynamic programmingCombinatorics+2	No attempts yet	1s	128 MB	Judgeable
Ransom NoteGiven a target note and a newspaper text, find the minimum number of contiguous clips (letters and spaces only, case-insensitive, reusable) needed to paste the note.	Hard8	Dynamic programmingString+2	No attempts yet	1s	128 MB	Judgeable
The Game of 31Given a partly played game of 31 with four cards of each value 1 to 6, determine the winner under perfect play.	Hard8	Game theoryDynamic programming+2	No attempts yet	1s	128 MB	Judgeable
Manelzuma's RevengeGiven a recursive square-substitution rule, answer queries that print a rectangular window of one generated fractal iteration.	Hard8	RecursionDivide and conquer	No attempts yet	1s	128 MB	Judgeable
GradingGiven point values and a threshold K, find the smallest integer at least K that cannot be any total score over all correct/wrong answer patterns.	Hard8	Dynamic programmingNumber theory+2	No attempts yet	2s	128 MB	Judgeable
SnailsEach of N snails moves in a fixed direction at speed 1 and stops at the fence, at any point an earlier snail crossed, or when it meets another snail simultaneously; find when the last snail stops.	Hard8	GeometrySimulation+2	No attempts yet	1s	128 MB	Judgeable
Railway ConnectionFind the cheapest route from station s to g in a multigraph where each maximal run of same-company edges is priced by that company's piecewise linear, concave fare table.	Hard8	GraphShortest path+2	No attempts yet	1s	128 MB	Judgeable
Chain-Confined PathFor a chain of circles where consecutive circles overlap, find the shortest path from the first center to the last center that stays inside the union of the circles.	Hard8	GeometryShortest path+2	No attempts yet	1s	128 MB	Judgeable
Generic PokerCount hands of L cards (ranks 1 to M, N copies each) that match a pattern of wildcards and variables shifted by pluses, then print the probability as an irreducible fraction.	Hard8	CombinatoricsBrute force+2	No attempts yet	1s	128 MB	Judgeable
A Strip of LandGiven a U by V grid of heights, find the largest-area rectangle whose height range is at most C and whose width is at most 100.	Hard8	Sliding windowMatrix+2	No attempts yet	2s	128 MB	Judgeable
Cow Ski AreaBuild the directed graph where each square has edges to same-or-lower neighbors, then find the minimum number of bidirectional edges to add so the whole graph becomes strongly connected.	Hard8	GraphDFS+2	No attempts yet	1s	128 MB	Judgeable
CloudsEach cloud is a polygon moving with the same velocity; count the separate time intervals during which the vertical beam at the origin intersects at least one cloud.	Hard8	GeometrySorting+2	No attempts yet	2s	128 MB	Judgeable
SweetsCount the ways to take up to m_i candies from each of n jars so the total is between a and b, modulo 2004.	Hard8	Dynamic programmingPrefix sum+2	No attempts yet	1s	128 MB	Judgeable
Bugs Integrated, Inc.Given a grid with some blocked cells, find the maximum number of 2x3 or 3x2 non-overlapping rectangles that fit on good cells.	Hard8	Dynamic programmingBit manipulation	No attempts yet	15s	128 MB	Judgeable
Word CountingGiven a rooted tree whose edges carry letter strings, count distinct occurrences of a query word along all paths from the root to the leaves, identifying each occurrence by its start and end position.	Hard8	String matchingTrie+2	No attempts yet	1s	128 MB	Judgeable
CircleGiven grid side k and circle radius r centered at a grid vertex, count cells the circle passes through, excluding cells touched only at a corner.	Hard8	MathGeometry+2	No attempts yet	1s	128 MB	Judgeable
Sevens, Twos and ZerosFind the smallest multiple of n that is at least n, uses only digits 7, 2, 0, and has at most 20 digits, or report NAV.	Hard8	BFSDynamic programming+2	No attempts yet	1s	128 MB	Judgeable