Problems

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Total results29,153 problems

Fruit Bowl
Medium7
Geometry, Simulation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Rectangles
Medium7
Dynamic programming, Sorting
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Pool
Medium7
Geometry, Implementation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Making Change
Medium7
Greedy, Dynamic programming+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Robot
Medium7
Graph, Shortest path+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Convex Hull Surface Area
Medium7
Geometry, Implementation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Dropping Tests
Medium7
Binary search, Greedy+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
The Cuboid Earth Theory
Medium7
Geometry, Math+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Do it!
Medium7
Greedy, Math+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Triangle
Medium7
Geometry, Number theory+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Maximum Sum of K Non-Overlapping Submatrices
Medium7
Dynamic programming, Prefix sum+2
No attempts yet
Time limit
2s
Memory limit
32 MB
Judgeable
Tree Game
Medium7
Tree, Game theory+2
No attempts yet
Time limit
1s
Memory limit
64 MB
Judgeable
Neighbours
Medium7
Sorting, Hash map+2
No attempts yet
Time limit
2s
Memory limit
64 MB
Judgeable
Book-case
Medium7
Dynamic programming, Implementation+1
No attempts yet
Time limit
1s
Memory limit
64 MB
Judgeable
Stock Exchange
Medium7
Divide and conquer, Segment tree+2
No attempts yet
Time limit
7s
Memory limit
32 MB
Judgeable
Triangulation
Medium7
Combinatorics, Math+2
No attempts yet
Time limit
1s
Memory limit
32 MB
Judgeable
Cards
Medium7
Simulation, Math+2
No attempts yet
Time limit
1s
Memory limit
16 MB
Judgeable
Counting Rectangles Drawn with Segments
Medium7
Geometry, Hash map+2
No attempts yet
Time limit
1s
Memory limit
16 MB
Judgeable
Reverse Numbers
Medium7
String, Math+1
No attempts yet
Time limit
1s
Memory limit
32 MB
Judgeable
Coloured Leaves
Medium7
Tree, DFS+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Cocktail
Medium7
Math, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Map Generator
Medium7
Dynamic programming, Combinatorics+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Map Generator Returns (MG-II)
Medium7
Probability, Dynamic programming+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Supersquare
Medium7
Math, Number theory+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Roman Corridor
Medium7
DFS, Graph+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Hospital
Medium7
Graph, DFS+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Counting Satisfying Assignments
Medium7
Implementation, Simulation+2
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
B-Matrix
Medium7
Dynamic programming, Matrix+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Superstitious Skylab Tower
Medium7
Math, Dynamic programming
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
GCD!
Medium7
Number theory, Math+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Jakarta Traffic Jam
Medium7
Graph, Shortest path+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Central Tree
Medium7
Tree, DFS+2
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
Lightning Energy Report
Medium7
Tree, Prefix sum+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Serial Numbers
Medium7
Dynamic programming, String matching+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Texture Tile
Medium7
Dynamic programming, Hash map+1
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
ACM Computer Factory
Medium7
Graph, BFS+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
One is Good, but Two is Better
Medium7
Brute force, Prefix sum+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Beach cut
Medium7
Geometry, Two pointers+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Tetris Alphabet
Medium7
Graph, Topological sort+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Better and Faster!
Medium7
Bit manipulation, Math+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Cave
Medium7
Stack, Greedy+1
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Everybody May Get Lost in Space
Medium7
Geometry, Math+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
(False) faces
Medium7
Combinatorics, Math+2
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Islands
Medium7
Union-find, Sorting+2
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Business Cards
Medium7
Math, Number theory+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Tower
Medium7
Math, Number theory+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Vase Collection
Medium7
Brute force, Backtracking+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Sightseeing Tour
Medium7
Graph, Union-find+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Floors
Medium7
Divide and conquer, Geometry+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Gophers
Medium7
Sorting, Binary search+2
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
Laundry
Medium7
Greedy, Sorting+1
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
ADOM
Medium7
Geometry, Brute force+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Artifact
Medium7
Prefix sum, Sliding window+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Violet Jigsaw Puzzle
Medium7
Backtracking, Implementation+1
No attempts yet
Time limit
5s
Memory limit
128 MB
Judgeable
The Existence of N
Medium7
Number theory, Math
No attempts yet
Time limit
5s
Memory limit
128 MB
Judgeable
Onion
Medium7
Geometry, Sorting+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Erdős Numbers
Medium7
Graph, BFS+2
No attempts yet
Time limit
5s
Memory limit
128 MB
Judgeable
Points
Medium7
Geometry, Sorting+2
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
Toy Cars
Medium7
Greedy, Heap+1
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
Bank Notes
Medium7
Dynamic programming, Greedy
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
Dicing
Medium7
Graph, Binary search+2
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
Template
Medium7
String, String matching+1
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
The Bus
Medium7
Dynamic programming, Sorting+1
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Formula One
Medium7
Greedy, Sorting+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Connectivity of a Permutation Graph
Medium7
Stack, Greedy+2
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
I'll Do It Tomorrow
Medium7
Greedy, Sorting+2
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Spies
Medium7
Graph, Greedy+1
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
The Islands
Medium7
Geometry, Sorting+1
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
Printed-Circuit Boards
Medium7
Tree, Dynamic programming+2
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
Smugglers
Medium7
Graph, Shortest path+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Mastermind II
Medium7
Brute force, Backtracking+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Treasure
Medium7
Graph, Simulation+2
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
Shuffle
Medium7
Combinatorics, Math+2
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
Railways
Medium7
Segment tree, Array+2
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
Superknight
Medium7
Math, Number theory+1
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
Parcel
Medium7
Stack, Dynamic programming+2
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Minuses
Medium7
Dynamic programming, Greedy+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Brackets
Medium7
Dynamic programming, Combinatorics+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Weaker Goldbach
Medium7
Number theory, Greedy+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Goldmine
Medium7
Sorting, Two pointers+2
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Chain
Medium7
Dynamic programming, Recursion+2
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Where to Build a Brewery?
Medium7
Prefix sum, Two pointers+2
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Stripes
Medium7
Game theory, Dynamic programming
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Viruses
Medium7
String matching, Trie+2
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Signatures
Medium7
Graph, DFS+2
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Binary Search Tree Code
Medium7
Tree, Recursion+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Musketeers
Medium7
Dynamic programming, Game theory+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Store-Keeper
Medium7
BFS, Graph+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Map
Medium7
Dynamic programming, Sorting+2
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
Primitivus
Medium7
Graph, Shortest path+2
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
How to Pack Containers?
Medium7
Greedy, Sorting+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
The Number of Symmetrical Choices
Medium7
Dynamic programming, String+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Genotypes
Medium7
Dynamic programming, Intervals+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Rods
Medium7
Geometry, Binary search+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Gambling Machine
Medium7
Graph, DFS+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Agents
Medium7
Graph, DFS+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Boxes
Medium7
Greedy, Prefix sum+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Word Equalizing
Medium7
String, Graph+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Trees
Medium7
Tree, Recursion+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Even Palindrome Decomposition
Medium7
Dynamic programming, String+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable

Title	Level	Topics	Solved	Time limit	Memory limit	Judge
Fruit BowlGiven a V-shaped bowl with left and right wall angles and height H, simulate greedily dropping unit circles to find how many fit below the rim.	Medium7	GeometrySimulation+1	No attempts yet	1s	128 MB	Judgeable
RectanglesFind the longest chain of rectangles where each rectangle's upper-right corner is strictly below and left of the next rectangle's lower-left corner.	Medium7	Dynamic programmingSorting	No attempts yet	1s	128 MB	Judgeable
PoolGiven cue, target, and blocker ball positions on a 108 by 54 table, decide which pockets the target can be potted into directly, with no other ball hit.	Medium7	GeometryImplementation+1	No attempts yet	1s	128 MB	Judgeable
Making ChangeChoose the fewest coins whose subsets can form every amount from 1 to C given bounded supplies of each denomination.	Medium7	GreedyDynamic programming+1	No attempts yet	1s	128 MB	Judgeable
RobotFind the shortest travel time for a robot that moves at speed 1 and turns 1 degree per second, hopping between points within distance R.	Medium7	GraphShortest path+2	No attempts yet	1s	128 MB	Judgeable
Convex Hull Surface AreaGiven up to 25 points in 3D, compute the surface area of their convex hull with triangular faces, rounded to the nearest integer.	Medium7	GeometryImplementation+1	No attempts yet	1s	128 MB	Judgeable
Dropping TestsGiven n test scores a_i/b_i, drop exactly k so the remaining total correct over total questions, times 100, is as large as possible.	Medium7	Binary searchGreedy+1	No attempts yet	1s	128 MB	Judgeable
The Cuboid Earth TheoryGiven a cuboid and a surface point, print the square of the shortest path length along the cuboid's surface from a vertex to that point.	Medium7	GeometryMath+2	No attempts yet	1s	128 MB	Judgeable
Do it!Choose when to shout 'do it!' over time so that positive, negative, and neutral workers finish their 100-unit fixtures with the smallest total finish time.	Medium7	GreedyMath+2	No attempts yet	1s	128 MB	Judgeable
TriangleCount the lattice points strictly inside a lattice triangle given by its three vertices, for many test cases.	Medium7	GeometryNumber theory+1	No attempts yet	1s	128 MB	Judgeable
Maximum Sum of K Non-Overlapping SubmatricesPick exactly K pairwise non-overlapping rectangular submatrices from an N x M matrix to maximize the sum of their elements.	Medium7	Dynamic programmingPrefix sum+2	No attempts yet	2s	32 MB	Judgeable
Tree GameOn a tree, players alternately move a token to an unchosen neighbor from Manco's start vertex; find all start vertices where Manco wins with optimal play.	Medium7	TreeGame theory+2	No attempts yet	1s	64 MB	Judgeable
NeighboursGiven n peaks on a w by h grid, count non-peak grid points by how many of their four axis directions contain a peak.	Medium7	SortingHash map+2	No attempts yet	2s	64 MB	Judgeable
Book-casePartition the books in alphabetical order across shelves of fixed width, allowing vertical books or horizontal stacks, to minimize total height.	Medium7	Dynamic programmingImplementation+1	No attempts yet	1s	64 MB	Judgeable
Stock ExchangeAnswer m online queries, each counting prices in a day range that fall within a decoded value range.	Medium7	Divide and conquerSegment tree+2	No attempts yet	7s	32 MB	Judgeable
TriangulationGiven n and m, compute the sum of triangulation counts T_3 + ... + T_n of convex polygons, reduced modulo m.	Medium7	CombinatoricsMath+2	No attempts yet	1s	32 MB	Judgeable
CardsFind the initial deck order that makes the shuffle, driven by the primes, output cards N down to 1.	Medium7	SimulationMath+2	No attempts yet	1s	16 MB	Judgeable
Counting Rectangles Drawn with SegmentsCount axis-aligned rectangles whose four sides are fully covered by the union of the given collinear segments.	Medium7	GeometryHash map+2	No attempts yet	1s	16 MB	Judgeable
Reverse NumbersGiven up to 10000-digit numbers M, decide whether some N satisfies M = N + Rev(N).	Medium7	StringMath+1	No attempts yet	1s	32 MB	Judgeable
Coloured LeavesGiven an unrooted tree whose leaves have fixed colors, choose an internal vertex as root and place the fewest labels so each leaf's color matches its last labeled vertex.	Medium7	TreeDFS+2	No attempts yet	1s	128 MB	Judgeable
CocktailA cube is lowered into a vessel holding two immiscible liquids of different densities; some liquid may spill. Find the final liquid height using Archimedes' principle.	Medium7	MathImplementation+2	No attempts yet	1s	128 MB	Judgeable
Map GeneratorGiven N planets each edge appears independently with probability P, find the probability that the resulting random graph is connected.	Medium7	Dynamic programmingCombinatorics+1	No attempts yet	1s	128 MB	Judgeable
Map Generator Returns (MG-II)Given N places and independent edge probability P, find the probability that the random graph on N vertices is connected.	Medium7	ProbabilityDynamic programming+2	No attempts yet	1s	128 MB	Judgeable
SupersquareFor each n, find the smallest 2n-digit number whose full value and both n-digit halves are nonzero perfect squares.	Medium7	MathNumber theory+2	No attempts yet	1s	128 MB	Judgeable
Roman CorridorFind a left-to-right path through the grid whose symbol string is a valid Roman numeral and has the smallest decimal value.	Medium7	DFSGraph+2	No attempts yet	1s	128 MB	Judgeable
HospitalGiven substitution lists for special nurses, find those who can never take vacation and all pairs that can go individually but not simultaneously.	Medium7	GraphDFS+2	No attempts yet	2s	128 MB	Judgeable
Counting Satisfying AssignmentsParse one logical formula and count how many of the 4096 assignments to twelve variables make it true.	Medium7	ImplementationSimulation+2	No attempts yet	2s	256 MB	Judgeable
B-MatrixFind two non-overlapping all-zero rectangles in a binary grid maximizing the total number of cells they cover.	Medium7	Dynamic programmingMatrix+2	No attempts yet	1s	128 MB	Judgeable
Superstitious Skylab TowerGiven a valid floor label with no digit 4 and no substring 13, count how many forbidden numbers precede it, then multiply by the floor height.	Medium7	MathDynamic programming	No attempts yet	1s	128 MB	Judgeable
GCD!For each pair n and k, compute gcd(n!, k); n can reach 1e9 so n! cannot be built, which forces a bound on the prime factors of k that matter.	Medium7	Number theoryMath+2	No attempts yet	1s	128 MB	Judgeable
Jakarta Traffic JamFind the fastest travel time between two intersections where each street is driven at half speed during its own daily rush hour, and you never stop to wait. Each test case gives up to 20 nodes; report the minimum minutes to two decimals.	Medium7	GraphShortest path+2	No attempts yet	1s	128 MB	Judgeable
Central TreeFor each weighted tree, find the vertex minimizing the sum of weighted distances to all other vertices and output that minimum sum.	Medium7	TreeDFS+2	No attempts yet	3s	128 MB	Judgeable
Lightning Energy ReportGiven a tree and many path updates that each add a value to every vertex on a path, report the final total at every vertex.	Medium7	TreePrefix sum+2	No attempts yet	1s	256 MB	Judgeable
Serial NumbersGiven up to 10 forbidden digit substrings, find the b-th smallest positive integer whose decimal form contains none of them as a substring.	Medium7	Dynamic programmingString matching+2	No attempts yet	1s	128 MB	Judgeable
Texture TileGiven an N x N image, find the largest square subimage whose top row equals its bottom row and left column equals its right column.	Medium7	Dynamic programmingHash map+1	No attempts yet	2s	256 MB	Judgeable
ACM Computer FactoryGiven machines with part-mask inputs, outputs, and hourly capacities, find the maximum factory throughput from the empty state to the full state.	Medium7	GraphBFS+1	No attempts yet	1s	128 MB	Judgeable
One is Good, but Two is BetterGiven an N by M grid of 0, 1, and 2, cover every 2 with two rectangles that avoid 1, minimizing the total area covered.	Medium7	Brute forcePrefix sum+2	No attempts yet	1s	128 MB	Judgeable
Beach cutGiven a polyline shoreline, pick two vertices at distance at most L and connect them below the shore to maximize the enclosed beach area.	Medium7	GeometryTwo pointers+1	No attempts yet	1s	128 MB	Judgeable
Tetris AlphabetGiven the final well of a Tetris game with lettered pieces, find the lexicographically smallest order in which the pieces could have landed.	Medium7	GraphTopological sort+2	No attempts yet	1s	128 MB	Judgeable
Better and Faster!Compute a CRC-style bit checksum of a string after each of up to 1e5 character substitutions, fast enough that recomputing from scratch times out.	Medium7	Bit manipulationMath+1	No attempts yet	2s	512 MB	Judgeable
CaveGiven floor and ceiling heights along a cave, find the maximum total area of settled fuel ponds that stay below the ceiling.	Medium7	StackGreedy+1	No attempts yet	3s	512 MB	Judgeable
Everybody May Get Lost in SpaceGiven three balls in 3D space, compute the exact volume of their union, rounded to six decimals.	Medium7	GeometryMath+2	No attempts yet	1s	512 MB	Judgeable
(False) facesGiven a 0/1 matrix of proposed left-right pairs, decide whether the number of perfect matchings is divisible by 4.	Medium7	CombinatoricsMath+2	No attempts yet	5s	512 MB	Judgeable
IslandsFor several nondecreasing sea levels, count the connected regions of cells whose height is above the water level.	Medium7	Union-findSorting+2	No attempts yet	3s	512 MB	Judgeable
Business CardsDecide whether a c x d sheet can be tiled exactly by axis-aligned a x b rectangles that may be rotated, for up to 1e5 cases.	Medium7	MathNumber theory+2	No attempts yet	1s	512 MB	Judgeable
TowerFor t up to 1e5 cases, given a2, N, and m, compute the sum of squares of the first N terms of the recurrence a1=1, an=2a2a(n-1)-a(n-2), modulo m.	Medium7	MathNumber theory+2	No attempts yet	1s	512 MB	Judgeable
Vase CollectionGiven up to 100 shape-decoration pairs drawn from a 36 by 36 grid, find the largest k for which some k shapes and k decorations form a complete k by k block of owned pairs.	Medium7	Brute forceBacktracking+2	No attempts yet	1s	128 MB	Judgeable
Sightseeing TourDecide whether a mixed graph of one-way and two-way streets has a closed tour that uses every street exactly once starting and ending at the same junction.	Medium7	GraphUnion-find+2	No attempts yet	1s	128 MB	Judgeable
FloorsGuillotine-cut a rectangle tiled by disjoint rectangles into the smallest possible pieces and output the largest piece's area.	Medium7	Divide and conquerGeometry+2	No attempts yet	1s	128 MB	Judgeable
GophersGiven gopher holes and CD players on a line, count holes covered by at least one player before and after each of d moves of a player, outputting d+1 counts.	Medium7	SortingBinary search+2	No attempts yet	3s	128 MB	Judgeable
LaundryAssign clothespin colors to each friend so socks and shirts each get one color, friends share no color, and the number of colors used is minimized.	Medium7	GreedySorting+1	No attempts yet	3s	128 MB	Judgeable
ADOMFor each board, remove every wall tile that the hero at the center of P cannot see within visibility radius r, given that walls block line of sight.	Medium7	GeometryBrute force+1	No attempts yet	1s	128 MB	Judgeable
ArtifactGiven n row intervals, choose k consecutive columns and pay the cost to extend each row's interval to cover them, minimizing total added tiles.	Medium7	Prefix sumSliding window+1	No attempts yet	1s	128 MB	Judgeable
Violet Jigsaw PuzzleCount how many ways to place and rotate the given pieces into an n by m rectangle so that all touching sides match tab-to-blank and border sides are flat.	Medium7	BacktrackingImplementation+1	No attempts yet	5s	128 MB	Judgeable
The Existence of NGiven a prime p, exponent m, and residue a, decide whether some positive n makes n^n + n^m congruent to a mod p.	Medium7	Number theoryMath	No attempts yet	5s	128 MB	Judgeable
OnionRepeatedly peel off the convex hull of the remaining points and report how many layers the onion has.	Medium7	GeometrySorting+2	No attempts yet	1s	128 MB	Judgeable
Erdős NumbersGiven papers with years and authors, find the shortest chain from Erdos to a person using strictly increasing years up to a query year.	Medium7	GraphBFS+2	No attempts yet	5s	128 MB	Judgeable
PointsGiven a pattern point set and up to 20 query sets, decide for each whether it is similar to the pattern under rotation, translation, reflection, and scaling.	Medium7	GeometrySorting+2	No attempts yet	3s	128 MB	Judgeable
Toy CarsBelady's caching: given a sequence of toy cars a child will request, minimize the number of times a car must be fetched from the shelf when at most k can be on the floor.	Medium7	GreedyHeap+1	No attempts yet	3s	128 MB	Judgeable
Bank NotesWith bounded supplies of each note denomination, find the fewest notes that sum exactly to k.	Medium7	Dynamic programmingGreedy	No attempts yet	3s	128 MB	Judgeable
DicingGiven an undirected multigraph of m games among n players, orient every edge so that the maximum number of edges pointing into any vertex is minimized.	Medium7	GraphBinary search+2	No attempts yet	3s	128 MB	Judgeable
TemplateFind a template whose overlapping occurrences cover every position of S, minimizing the template length.	Medium7	StringString matching+1	No attempts yet	3s	128 MB	Judgeable
The BusFind a path from (1,1) to (n,m) moving only east and north that collects the maximum total of passenger weights at visited intersections.	Medium7	Dynamic programmingSorting+1	No attempts yet	3s	512 MB	Judgeable
Formula OneGiven how many overtakes each starting-position car makes, decide whether some sequence of pairwise passes could produce exactly those counts.	Medium7	GreedySorting+2	No attempts yet	1s	128 MB	Judgeable
Connectivity of a Permutation GraphRead a permutation of up to one million elements and report the connected components of the graph joining i and j whenever i < j and a_i > a_j.	Medium7	StackGreedy+2	No attempts yet	2s	256 MB	Judgeable
I'll Do It TomorrowGiven n jobs with lengths and deadlines, find the longest idle prefix of days, counting from day 1, before some work must begin.	Medium7	GreedySorting+2	No attempts yet	2s	256 MB	Judgeable
SpiesGiven a functional graph where spy k shadows a_k, choose the largest subset S such that every member of S is shadowed by at least one spy outside S.	Medium7	GraphGreedy+1	No attempts yet	3s	512 MB	Judgeable
The IslandsGiven nested rectilinear coastlines listed parent-before-child, find the maximum nesting depth among islands and lakes.	Medium7	GeometrySorting+1	No attempts yet	3s	128 MB	Judgeable
Printed-Circuit BoardsGiven a series-parallel circuit described recursively, find the minimum number of connections that must be routed on the top side so every unit is reached from the top.	Medium7	TreeDynamic programming+2	No attempts yet	3s	128 MB	Judgeable
SmugglersFind a cycle from gold back to gold that minimizes total conversion cost plus 50% of the cheapest metal's price along the cycle.	Medium7	GraphShortest path+2	No attempts yet	1s	128 MB	Judgeable
Mastermind IIGiven c codes and their A/B compatibility scores with a hidden code of length c, find the lexicographically smallest code consistent with all scores.	Medium7	Brute forceBacktracking+2	No attempts yet	1s	128 MB	Judgeable
TreasureGiven clockwise-ordered corridors between vaults and guards following the right-hand rule, find which guards eventually collect all pieces of information.	Medium7	GraphSimulation+2	No attempts yet	3s	128 MB	Judgeable
ShuffleGiven a permutation b and an integer l, count the permutations a whose l-th iterate equals b, modulo 1e9+7.	Medium7	CombinatoricsMath+2	No attempts yet	3s	128 MB	Judgeable
RailwaysProcess train seat requests in order; accept a request only if every section it covers has enough free seats, and report T or N for each.	Medium7	Segment treeArray+2	No attempts yet	3s	128 MB	Judgeable
SuperknightFor each knight, decide whether the move vectors generate the full integer lattice of board squares.	Medium7	MathNumber theory+1	No attempts yet	3s	128 MB	Judgeable
ParcelGiven an n by n grid of 0 (arable) and 1 (waste), find the largest all-zero rectangle and print its area. n can be up to 2000.	Medium7	StackDynamic programming+2	No attempts yet	3s	512 MB	Judgeable
MinusesGiven a signed sum of distinct variables, find the fewest bracket pairs needed to turn the all-minus chain into an equivalent expression.	Medium7	Dynamic programmingGreedy+2	No attempts yet	1s	128 MB	Judgeable
BracketsCount the ways to fully bracket a minus chain so that the result equals a target expression with given signs, modulo 1e9.	Medium7	Dynamic programmingCombinatorics+1	No attempts yet	1s	128 MB	Judgeable
Weaker GoldbachFor each given integer, write it as a sum of distinct odd primes using the fewest terms, breaking ties by the lexicographically smallest ascending list.	Medium7	Number theoryGreedy+2	No attempts yet	1s	128 MB	Judgeable
GoldmineGiven n points and an axis-aligned rectangle of fixed width s and height w, find the maximum number of points the rectangle can cover, borders included.	Medium7	SortingTwo pointers+2	No attempts yet	3s	512 MB	Judgeable
ChainGiven which rings of a bytish chain are on a bar, find the minimum number of legal put-on/take-off moves to remove all rings.	Medium7	Dynamic programmingRecursion+2	No attempts yet	3s	512 MB	Judgeable
Where to Build a Brewery?On a ring of cities with given edge lengths and demands, pick the city minimizing total demand-weighted shortest-path distance around the ring.	Medium7	Prefix sumTwo pointers+2	No attempts yet	3s	512 MB	Judgeable
StripesGiven stripe lengths c, z, n, decide for each board length p whether the first player wins the impartial placement game.	Medium7	Game theoryDynamic programming	No attempts yet	3s	512 MB	Judgeable
VirusesGiven a set of forbidden binary words, decide whether an infinite binary sequence exists that avoids all of them as contiguous substrings.	Medium7	String matchingTrie+2	No attempts yet	3s	512 MB	Judgeable
SignaturesGiven vouching edges among workers, commanders have no guarantors; list clerks whose reachability from some non-spy commander depends on a single commander.	Medium7	GraphDFS+2	No attempts yet	3s	512 MB	Judgeable
Binary Search Tree CodeGiven n and k, output the n-th preorder string among all BSTs built from the first k letters, listed in alphabetical order.	Medium7	TreeRecursion+2	No attempts yet	1s	128 MB	Judgeable
MusketeersGiven a tournament matrix on n people in a circle, determine everyone who can be the last survivor when adjacent duels are scheduled in any order.	Medium7	Dynamic programmingGame theory+2	No attempts yet	1s	128 MB	Judgeable
Store-KeeperOn an n by m grid of cases and empty fields, the keeper walks and pushes a parcel; find the minimum number of pushes to reach the target field.	Medium7	BFSGraph+2	No attempts yet	1s	128 MB	Judgeable
MapPartition n populations into m groups to minimize the sum over each group of \|value - group median\|, where the median can be any value meeting the half-half condition.	Medium7	Dynamic programmingSorting+2	No attempts yet	3s	128 MB	Judgeable
PrimitivusGiven a set of ordered pairs, find the shortest sequence in which every pair appears consecutively at least once.	Medium7	GraphShortest path+2	No attempts yet	3s	128 MB	Judgeable
How to Pack Containers?Given boxes with power-of-two sizes and values, find the minimum total value of boxes that can exactly fill all arrived containers, or report impossibility.	Medium7	GreedySorting+1	No attempts yet	1s	128 MB	Judgeable
The Number of Symmetrical ChoicesGiven two word sequences of length n, count how many of the 2^n ways of picking one word per index produce a palindrome when concatenated.	Medium7	Dynamic programmingString+2	No attempts yet	1s	128 MB	Judgeable
GenotypesGiven budding rules A1 -> A2 A3, decide for each target word whether it can be derived from some number of supergenes S, and report the minimum count.	Medium7	Dynamic programmingIntervals+2	No attempts yet	1s	128 MB	Judgeable
RodsFor each rod, compute the distance from the chord midpoint to the arc midpoint after it bends into a circular arc of given arc length and chord length, rounded to an integer.	Medium7	GeometryBinary search+1	No attempts yet	1s	128 MB	Judgeable
Gambling MachineGiven n generators, each mapping to a subset of generators, decide whether some choice of output order lets the machine halt at Gn with all sets exhausted (defeat) or must it halt elsewhere.	Medium7	GraphDFS+2	No attempts yet	1s	128 MB	Judgeable
AgentsGiven a directed graph of who unmasked whom and the bribe cost of some agents, find the minimum cost to bribe agents so arrests cascade to everyone, or the smallest unreachable, unbribable agent.	Medium7	GraphDFS+2	No attempts yet	1s	128 MB	Judgeable
BoxesBoxes stand in a circle with at most n balls total; move balls to neighbors so each box holds at most one, minimizing the number of moves.	Medium7	GreedyPrefix sum+2	No attempts yet	1s	128 MB	Judgeable
Word EqualizingAppend the given words to x and y any number of times to make them equal, and output the minimum total number of appends, or NIE if impossible.	Medium7	StringGraph+2	No attempts yet	1s	128 MB	Judgeable
TreesGiven a sequence of leaf levels, decide whether it is a valid complete binary tree; if so, output the genealogical and bracket representations.	Medium7	TreeRecursion+2	No attempts yet	1s	128 MB	Judgeable
Even Palindrome DecompositionDecide whether a string can be split entirely into even-length palindromes, and if so report the minimum and maximum number of parts.	Medium7	Dynamic programmingString+2	No attempts yet	1s	128 MB	Judgeable