Problems

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Total results29,125 problems

Lines
Medium7
Geometry, Binary search+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Mountain Hikes
Medium7
Graph, Union-find+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Klocki
Medium7
Graph, Combinatorics+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Returning Blocks
Medium7
Dynamic programming, Combinatorics
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Dividing the Highway into Repair Segments
Medium7
Math, Sorting+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Cylinders
Medium7
BFS, Graph+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Cheapest Closed Route
Medium7
Graph, Shortest path+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Sunset Views 2
Medium7
Array, Prefix sum+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Guessing Game
Medium7
Union-find, Prefix sum+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Number of Peanuts
Medium7
Simulation, Implementation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
LinkNet
Medium7
Intervals, Greedy+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Blockade
Medium7
Graph, Shortest path+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Error Correction
Medium7
Dynamic programming, String matching+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Visibility
Medium7
Stack, Graph+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Alliance
Medium7
Graph, Greedy+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Two-Colored Towers of Hanoi
Medium7
Dynamic programming, Recursion+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Rigged Tournament
Medium7
Graph, DFS
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Group Excursion
Medium7
Graph, DFS+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Non-Attacking Knights
Medium7
Graph, BFS+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Apteka
Medium7
Dynamic programming, Greedy+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Eraser
Medium7
Greedy, String matching
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Lamps
Medium7
Greedy, Heap+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Truncatable Primes
Medium7
Backtracking, Number theory
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Officials
Medium7
Greedy, Tree+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Cake Piece
Medium7
Binary search, Sorting+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Tigers
Medium7
Greedy, Sorting+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Bus
Medium7
Shortest path, Geometry+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Photos
Medium7
Segment tree, Sorting+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Last Digits
Medium7
Number theory, Math
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Byteland
Medium7
Minimum spanning tree, Union-find+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Product of Distinct Integers
Medium7
Number theory, Greedy+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Pressing and Glittering Records
Medium7
Greedy, Heap
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
Bridge Pillars
Medium7
Number theory, Prefix sum
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Weights and Scales
Medium7
Prefix sum, Hash map
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
The Structure
Medium7
Segment tree, Prefix sum+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Halloween
Medium7
Dynamic programming, Intervals
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Arithmetic Subsequences
Medium7
Math, Brute force
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Expressways
Medium7
Graph, Math+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Roundup
Medium7
Prefix sum, Matrix+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Points
Medium7
Geometry, Combinatorics+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Hostile States
Medium7
Graph
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Springs
Medium7
Prefix sum, Binary search+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Maximized Subset
Medium7
Greedy, Sorting
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
The Funny Informatics Contest
Medium7
Greedy, Intervals+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
ABC
Medium7
Dynamic programming, Greedy+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Guziki
Medium7
Number theory, Math
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Room Numbers
Medium7
Dynamic programming, String+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Friendly Points
Medium7
Segment tree, Sorting+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Strange Planet
Medium7
Combinatorics, Math
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Mouse in the Maze
Medium7
Binary search, Shortest path+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Tag
Medium7
Tree, Game theory+2
No attempts yet
Time limit
5s
Memory limit
128 MB
Judgeable
Continent
Medium7
Graph, Geometry+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Substring Draw
Medium7
String matching, Combinatorics+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Divisibility
Medium7
Graph, Topological sort
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Handel
Medium7
Graph
No attempts yet
Time limit
10s
Memory limit
128 MB
Judgeable
Bouquets
Medium7
Graph, BFS
No attempts yet
Time limit
5s
Memory limit
128 MB
Judgeable
Subspecies
Medium7
Divide and conquer, Sorting+2
No attempts yet
Time limit
10s
Memory limit
128 MB
Judgeable
Never Say Never
Medium7
Sorting, Intervals+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Painted Numbers
Medium7
Number theory, Math
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Investments
Medium7
Graph
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Separating Lines
Medium7
Geometry, Binary search+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Tournament
Medium7
Probability, Tree+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Fractions
Medium7
Number theory, Combinatorics+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
The Bike Trip
Medium7
Matrix, Graph
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
Museum
Medium7
Geometry
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Number of Obtainable Amounts
Medium7
Dynamic programming, Math+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Hamster
Medium7
Dynamic programming, Sorting
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Guessing Game
Medium7
Binary search, Combinatorics+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Paper Strips
Medium7
Dynamic programming, Divide and conquer+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
The Game
Medium7
Game theory, Topological sort+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Jigsaw Puzzle
Medium7
Backtracking, Graph
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Cactus Graph
Medium7
DFS, Graph
No attempts yet
Time limit
5s
Memory limit
128 MB
Judgeable
Magic Rectangle
Medium7
Dynamic programming, Combinatorics
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Banner Repair
Medium7
Dynamic programming, String
No attempts yet
Time limit
10s
Memory limit
128 MB
Judgeable
Moda na zwycięstwo
Medium7
Sliding window, Graph+1
No attempts yet
Time limit
20s
Memory limit
128 MB
Judgeable
Pattern
Medium7
String matching, Two pointers+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Almost LCS
Medium7
Prefix sum, Two pointers+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Visas
Medium7
Dynamic programming, Sorting+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Course Registration System
Medium7
Graph
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Trial Problem
Medium7
Math, Number theory
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Billabongs
Medium7
Tree, Greedy+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Toy-Cleanup Robots
Medium7
Binary search, Greedy+1
No attempts yet
Time limit
5s
Memory limit
64 MB
Judgeable
Bazza and Shazza
Medium7
Segment tree, Number theory+1
No attempts yet
Time limit
13s
Memory limit
230 MB
Judgeable
Self-Assembly
Medium7
Graph, Topological sort
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
Pollution Solution
Medium7
Geometry
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Up a Tree
Medium7
Tree, Backtracking+2
No attempts yet
Time limit
6s
Memory limit
128 MB
Judgeable
Accelerator
Medium7
Dynamic programming, Sorting+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Slicing Tree
Medium7
Dynamic programming, Tree
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Square Annulus
Medium7
Geometry, Binary search+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Color Length
Medium7
Dynamic programming
No attempts yet
Time limit
10s
Memory limit
128 MB
Judgeable
Equipment
Medium7
Brute force, Bit manipulation+1
No attempts yet
Time limit
5s
Memory limit
128 MB
Judgeable
Furniture Factory
Medium7
Graph, Intervals
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Laptop
Medium7
Dynamic programming, Greedy+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Pizza Delivery
Medium7
Dynamic programming, Intervals
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Soju
Medium7
Geometry, Sorting
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
Popping Groups
Medium7
Dynamic programming, String+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Mines
Medium7
Graph, DFS+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Tour Belt
Medium7
Minimum spanning tree, Union-find+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Airport
Medium7
Binary search, Greedy+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
GC-Ratio
Medium7
Binary search, Prefix sum
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable

Title	Level	Topics	Solved	Time limit	Memory limit	Judge
LinesFind the line through a fixed point P that minimizes the maximum distance from P's line to any of n given points, and print that minimum distance rounded down to three decimals.	Medium7	GeometryBinary search+2	No attempts yet	1s	128 MB	Judgeable
Mountain HikesGiven a weighted undirected graph, repeatedly pick any simple cycle, delete the minimum-weight edge on it, and count how many edges are deleted before no cycle remains.	Medium7	GraphUnion-find+2	No attempts yet	1s	128 MB	Judgeable
KlockiFind the length of the longest closed walk in the arrangement graph of k blocks in n drawers, returning to the start with no repeats except the endpoints.	Medium7	GraphCombinatorics+2	No attempts yet	1s	128 MB	Judgeable
Returning BlocksCount the ways to fill empty cells of a 2-by-n board with distinct blocks so every row and column reads in increasing order.	Medium7	Dynamic programmingCombinatorics	No attempts yet	1s	128 MB	Judgeable
Dividing the Highway into Repair SegmentsChoose a start offset s in [1,m] for tiling the number line into length-m segments, minimizing how many segments contain at least one of the given damaged kilometers, and list all optimal s.	Medium7	MathSorting+2	No attempts yet	1s	128 MB	Judgeable
CylindersTwo identical cylinders with the same n scale marks start empty; find the minimum number of fill, drain, and pour actions to leave exactly l millilitres in one cylinder, or report it impossible.	Medium7	BFSGraph+2	No attempts yet	1s	128 MB	Judgeable
Cheapest Closed RouteGiven an undirected weighted graph, find the minimum total weight of a non-empty closed walk that never repeats an edge, or report none exists.	Medium7	GraphShortest path+2	No attempts yet	1s	128 MB	Judgeable
Sunset Views 2For each point on an n by n grid, take the maximum building height within Manhattan distance k, then sum all these maxima.	Medium7	ArrayPrefix sum+2	No attempts yet	1s	128 MB	Judgeable
Guessing GameFind the largest prefix of interval parity answers that stays consistent with some 0/1 sequence of length one billion.	Medium7	Union-findPrefix sum+1	No attempts yet	1s	128 MB	Judgeable
Number of PeanutsSimulate a squirrel that toggles peanuts on a grid while turning left or right, and count the peanuts after t seconds with t up to 1e9.	Medium7	SimulationImplementation+1	No attempts yet	1s	128 MB	Judgeable
LinkNetGiven intervals on a line, schedule each transmission into a tick so that no interval in the same tick contains another interval's endpoint strictly inside it, and no point is used twice per tick; find the minimum ticks.	Medium7	IntervalsGreedy+2	No attempts yet	1s	128 MB	Judgeable
BlockadeGiven a directed graph, find the minimum number of edges whose removal disconnects server 1 from server n.	Medium7	GraphShortest path+1	No attempts yet	1s	128 MB	Judgeable
Error CorrectionGiven letter-to-bits codebook and binary strings, decide if exactly one letter sequence encodes to within one bit flip.	Medium7	Dynamic programmingString matching+1	No attempts yet	1s	128 MB	Judgeable
VisibilityGiven a sequence, count pairs whose relationship is in the transitive closure of the direct-visibility relation defined by strictly smaller intervening elements.	Medium7	StackGraph+2	No attempts yet	1s	128 MB	Judgeable
AllianceGiven a bipartite graph, pick the smallest set of edges so that every vertex which has any edge has at least one chosen incident edge.	Medium7	GraphGreedy+2	No attempts yet	1s	128 MB	Judgeable
Two-Colored Towers of HanoiThe task is to compute the minimum moves to gather odd disks on peg B and even disks on peg C under Hanoi rules.	Medium7	Dynamic programmingRecursion+1	No attempts yet	1s	128 MB	Judgeable
Rigged TournamentCount the players that can be made champion by scheduling matches against opponents they are certain to beat.	Medium7	GraphDFS	No attempts yet	1s	128 MB	Judgeable
Group ExcursionDecide whether each tourist's two visit wishes can be satisfied together and output the lexicographically smallest visit list.	Medium7	GraphDFS+2	No attempts yet	1s	128 MB	Judgeable
Non-Attacking KnightsPlace the most knights on a board with blocked squares so no two attack each other.	Medium7	GraphBFS+1	No attempts yet	1s	128 MB	Judgeable
AptekaPay each swapped person by distance times their fee and reach the front with the smallest total cost.	Medium7	Dynamic programmingGreedy+1	No attempts yet	1s	512 MB	Judgeable
EraserPick the alphabetically last name that appears as a subsequence in every scrap and keep bitek when nothing later exists.	Medium7	GreedyString matching	No attempts yet	1s	512 MB	Judgeable
LampsAdd up to K lamps along a ceiling to minimize the total area of the dark triangles between neighboring lamps, and report the minimum as a reduced fraction.	Medium7	GreedyHeap+2	No attempts yet	1s	512 MB	Judgeable
Truncatable PrimesCount integers in [a, b] whose every prefix from the left is prime.	Medium7	BacktrackingNumber theory	No attempts yet	1s	512 MB	Judgeable
OfficialsIn a rooted tree of officials, match each denouncer with a distinct descendant subordinate to maximize the number of executed officials.	Medium7	GreedyTree+1	No attempts yet	1s	512 MB	Judgeable
Cake PieceFind the k-th largest piece area after cutting a rectangle with n cuts in each direction.	Medium7	Binary searchSorting+2	No attempts yet	1s	512 MB	Judgeable
TigersSort tigers by size and put each one in an enclosure whose smallest tiger it cannot eat, opening a new enclosure when none fits.	Medium7	GreedySorting+1	No attempts yet	1s	512 MB	Judgeable
BusFind the fastest directed route that visits the midpoints of given streets in order while turning at most 90 degrees at intersections.	Medium7	Shortest pathGeometry+1	No attempts yet	1s	512 MB	Judgeable
PhotosFind the point covered by the largest number of given axis-aligned rectangles.	Medium7	Segment treeSorting+1	No attempts yet	1s	512 MB	Judgeable
Last DigitsPrint every k-digit number (with leading zeros) whose a-th power ends in itself.	Medium7	Number theoryMath	No attempts yet	1s	512 MB	Judgeable
BytelandDecide for every proposed road whether some cheapest network connecting all towns can include it.	Medium7	Minimum spanning treeUnion-find+1	No attempts yet	1s	512 MB	Judgeable
Product of Distinct IntegersDecide whether n can be expressed as a product of k distinct positive integers.	Medium7	Number theoryGreedy+1	No attempts yet	1s	128 MB	Judgeable
Pressing and Glittering RecordsPick k pressing days and k glittering days over n days so each press day precedes its glitter day at minimum total cost.	Medium7	GreedyHeap	No attempts yet	3s	128 MB	Judgeable
Bridge PillarsPick a modulus m above 1 that keeps the largest group of pillar heights sharing one remainder, with ties broken toward the larger m.	Medium7	Number theoryPrefix sum	No attempts yet	1s	128 MB	Judgeable
Weights and ScalesPlace one gray weight on the empty pan, then repeatedly merge each balanced scale in the nested tower, and report the fewest weights that can remain.	Medium7	Prefix sumHash map	No attempts yet	1s	128 MB	Judgeable
The StructureA tower splits the top load equally down its columns, and after each strength update you report how many queued visitors from the front it can hold.	Medium7	Segment treePrefix sum+1	No attempts yet	1s	128 MB	Judgeable
HalloweenGiven the sequence of required costumes, find the fewest put-ons when costumes stack and removals are free.	Medium7	Dynamic programmingIntervals	No attempts yet	1s	128 MB	Judgeable
Arithmetic SubsequencesCount index triples i<j<k in a permutation of 1 to n whose values form a three-term arithmetic progression.	Medium7	MathBrute force	No attempts yet	1s	128 MB	Judgeable
ExpresswaysDecide whether some subset of the given roads touches every city an odd number of times.	Medium7	GraphMath+1	No attempts yet	1s	128 MB	Judgeable
RoundupCount the axis-aligned squares of side at least 2 whose border cells are all 1 in an n by n binary grid.	Medium7	Prefix sumMatrix+1	No attempts yet	1s	128 MB	Judgeable
PointsCount triangles formed by white points that have no black point strictly inside them.	Medium7	GeometryCombinatorics+2	No attempts yet	1s	128 MB	Judgeable
Hostile StatesAssign each undecided city to one of two states to minimize the number of roads crossing between states.	Medium7	Graph	No attempts yet	1s	128 MB	Judgeable
SpringsPick one integer target length for the k shortest springs to minimize the total triangular stretching cost.	Medium7	Prefix sumBinary search+1	No attempts yet	1s	128 MB	Judgeable
Maximized SubsetYou choose k elements from the multiset to maximize the largest x with every integer from 1 to x as a subset sum.	Medium7	GreedySorting	No attempts yet	1s	128 MB	Judgeable
The Funny Informatics ContestDecide whether each round can be assigned a non-overlapping continuous block of the required length inside its time window.	Medium7	GreedyIntervals+1	No attempts yet	1s	128 MB	Judgeable
ABCFind the length of the longest nondecreasing common subsequence of two strings over a, b, and c.	Medium7	Dynamic programmingGreedy+1	No attempts yet	1s	128 MB	Judgeable
GuzikiCount the lines through the center of an odd n by n grid that contain exactly g buttons and print -1 when the count exceeds 1e12.	Medium7	Number theoryMath	No attempts yet	1s	128 MB	Judgeable
Room NumbersCount the distinct numbers formed by flipping each 6 or 9 in n independently that are at most h, modulo 9999997.	Medium7	Dynamic programmingString+2	No attempts yet	1s	128 MB	Judgeable
Friendly PointsCount the pairs of points whose axis-aligned rectangle contains no other point strictly inside.	Medium7	Segment treeSorting+1	No attempts yet	1s	128 MB	Judgeable
Strange PlanetCount binary strings of length n whose Hamming distances to three given binary strings are all equal, modulo 1e9+7.	Medium7	CombinatoricsMath	No attempts yet	1s	128 MB	Judgeable
Mouse in the MazeFind the largest starting thickness allowing a path from s to d when visited rooms add their cheese weight and each corridor caps the current thickness.	Medium7	Binary searchShortest path+1	No attempts yet	1s	128 MB	Judgeable
TagA pursuer at K always steps toward an evader at J on a tree while the evader moves or waits to maximize the capture time.	Medium7	TreeGame theory+2	No attempts yet	5s	128 MB	Judgeable
ContinentCount the countries formed by up to 8000 border segments and print each polygon area in ascending order.	Medium7	GraphGeometry+1	No attempts yet	1s	128 MB	Judgeable
Substring DrawTwo slips are drawn without replacement from all position-counted substrings of a word, and the tie probability is printed as a reduced fraction.	Medium7	String matchingCombinatorics+1	No attempts yet	1s	128 MB	Judgeable
DivisibilityDecide whether a directed graph matches the divisibility relation of some set of distinct natural numbers.	Medium7	GraphTopological sort	No attempts yet	1s	128 MB	Judgeable
HandelDecide whether trade amounts within the given bounds can make every country's total purchases equal its total sales.	Medium7	Graph	No attempts yet	10s	128 MB	Judgeable
BouquetsDecide whether two directed graphs with distinct outgoing labels spell the same strings on closed walks from node 1 back to node 1.	Medium7	GraphBFS	No attempts yet	5s	128 MB	Judgeable
SubspeciesCount for each specimen how many others differ by at most D in length, W in weight, and S in segments.	Medium7	Divide and conquerSorting+2	No attempts yet	10s	128 MB	Judgeable
Never Say NeverDecide whether two employees employed at the same moment ever have equal linear effectiveness values.	Medium7	SortingIntervals+1	No attempts yet	2s	128 MB	Judgeable
Painted NumbersDecide the red or blue color of each positive rational when adding 1 flips the color, reciprocals share it, and 1 is red.	Medium7	Number theoryMath	No attempts yet	1s	128 MB	Judgeable
InvestmentsPick some priced investments to unlock revenue benefits that each require a set of investments and maximize revenue minus cost.	Medium7	Graph	No attempts yet	1s	128 MB	Judgeable
Separating LinesFor each of up to 100000 query lines, report whether the given points fall on both sides of it or touch it.	Medium7	GeometryBinary search+1	No attempts yet	1s	128 MB	Judgeable
TournamentCompute the chance that two named entrants meet in a knockout bracket with random seeding and even match odds.	Medium7	ProbabilityTree+1	No attempts yet	1s	128 MB	Judgeable
FractionsCount pairs (a, b) up to N whose fraction equals a fraction with both parts up to M.	Medium7	Number theoryCombinatorics+1	No attempts yet	1s	128 MB	Judgeable
The Bike TripStarting from place 1, follow staged runs of typed directed roads and list every possible end place.	Medium7	MatrixGraph	No attempts yet	3s	128 MB	Judgeable
MuseumDecide whether an orthogonal integer-coordinate museum polygon has a point that sees every interior point.	Medium7	Geometry	No attempts yet	2s	128 MB	Judgeable
Number of Obtainable AmountsCount the distinct totals formable from bounded banknotes where each denomination is a multiple of the previous one, modulo 1e9+7.	Medium7	Dynamic programmingMath+1	No attempts yet	1s	128 MB	Judgeable
HamsterSchedule food packages with spoil days, meal counts and qualities to maximize total meal quality over M days.	Medium7	Dynamic programmingSorting	No attempts yet	2s	128 MB	Judgeable
Guessing GameFind the fewest adaptive rounds of up to K cell reveals that always identify the length of a painted prefix of N cells.	Medium7	Binary searchCombinatorics+1	No attempts yet	1s	128 MB	Judgeable
Paper StripsCount the sets of dyadic pieces from repeated halving that exactly tile sectors a to b, modulo m.	Medium7	Dynamic programmingDivide and conquer+1	No attempts yet	1s	128 MB	Judgeable
The GameTwo tokens sit on two directed acyclic boards and players alternate moving one token along an edge, and each query asks whether the first player wins.	Medium7	Game theoryTopological sort+1	No attempts yet	1s	128 MB	Judgeable
Jigsaw PuzzleGiven each piece's unordered neighbor list and the first two pieces of the top row, reconstruct the N by M puzzle grid or report that it is not unique.	Medium7	BacktrackingGraph	No attempts yet	1s	128 MB	Judgeable
Cactus GraphCount the simple cycles in an undirected graph, or print NIE when two cycles share more than one vertex.	Medium7	DFSGraph	No attempts yet	5s	128 MB	Judgeable
Magic RectangleCount the ways to fill a 3 by N grid with 1 to 3N so each row and column increases, matching the prefilled cells, modulo 1000007.	Medium7	Dynamic programmingCombinatorics	No attempts yet	2s	128 MB	Judgeable
Banner RepairTransform one uppercase banner string into another with block insertions and deletions where each block of length S costs X plus S times Y.	Medium7	Dynamic programmingString	No attempts yet	10s	128 MB	Judgeable
Moda na zwycięstwoFind the shortest block of consecutive episodes whose dated relationships connect a parent to its child through a chain of pairs.	Medium7	Sliding windowGraph+1	No attempts yet	20s	128 MB	Judgeable
PatternCount the positions in the text where the pattern matches when every letter is repeated the same number of times.	Medium7	String matchingTwo pointers+1	No attempts yet	1s	128 MB	Judgeable
Almost LCSGiven two binary strings up to 100000 characters, find the longest 0^a1^b or 1^a0^b string that is a subsequence of both.	Medium7	Prefix sumTwo pointers+1	No attempts yet	1s	128 MB	Judgeable
VisasChoose visa requests and give each a distinct day inside its window for the largest total payment.	Medium7	Dynamic programmingSorting+1	No attempts yet	1s	128 MB	Judgeable
Course Registration SystemStudents choose courses from preference lists within per-course and per-student limits to maximize total enrollments, or the answer is impossible.	Medium7	Graph	No attempts yet	1s	128 MB	Judgeable
Trial ProblemGiven n up to 2010, compute the final value of the triple loop that adds each floored s*k/i term modulo 2010.	Medium7	MathNumber theory	No attempts yet	1s	128 MB	Judgeable
BillabongsConnect the weighted forest into one network with fixed-cost links so the longest travel time between any two ponds is as small as possible.	Medium7	TreeGreedy+1	No attempts yet	1s	256 MB	Judgeable
Toy-Cleanup RobotsDecide whether weight-limited robots and size-limited robots can clear every toy and compute the shortest clearing time.	Medium7	Binary searchGreedy+1	No attempts yet	5s	64 MB	Judgeable
Bazza and ShazzaPoint updates set grid cells to new values and each query asks for the GCD of all values inside a rectangle.	Medium7	Segment treeNumber theory+1	No attempts yet	13s	230 MB	Judgeable
Self-AssemblyDecide whether unlimited rotatable square tiles with signed edge labels can form an arbitrarily large compatible assembly.	Medium7	GraphTopological sort	No attempts yet	3s	128 MB	Judgeable
Pollution SolutionCompute the area where a half-disk of radius r centered at the origin overlaps a given polygon above the x-axis.	Medium7	Geometry	No attempts yet	1s	128 MB	Judgeable
Up a TreeGiven three garbled preorder, inorder and postorder outputs from mixed-up recursive calls, list every call assignment and the smallest tree that fits each one.	Medium7	TreeBacktracking+2	No attempts yet	6s	128 MB	Judgeable
AcceleratorMatch every red point on a discrete circle to a distinct blue point so the sum of shorter-arc distances is as small as possible.	Medium7	Dynamic programmingSorting+1	No attempts yet	1s	128 MB	Judgeable
Slicing TreePlace the rotated rectangles under the slicing-tree constraints so the enclosing rectangle has minimum area.	Medium7	Dynamic programmingTree	No attempts yet	1s	128 MB	Judgeable
Square AnnulusGiven N points, find the minimum width of a concentric axis-parallel square ring that contains all of them.	Medium7	GeometryBinary search+2	No attempts yet	1s	128 MB	Judgeable
Color LengthMerge two color strings while keeping each order so the sum of first-to-last spans of all colors is as small as possible.	Medium7	Dynamic programming	No attempts yet	10s	128 MB	Judgeable
EquipmentChoose exactly K of N pieces, each with five scores, to maximize the sum of the five category maxima.	Medium7	Brute forceBit manipulation+1	No attempts yet	5s	128 MB	Judgeable
Furniture FactoryDecide if m workers can finish n preemptible jobs with release times and deadlines when each job takes at most one worker at a time.	Medium7	GraphIntervals	No attempts yet	2s	128 MB	Judgeable
LaptopPlace each unit-time task inside its release time and deadline so idle gaps between tasks are as few as possible.	Medium7	Dynamic programmingGreedy+2	No attempts yet	2s	128 MB	Judgeable
Pizza DeliveryChoose which houses on a road to visit and in what order so earnings minus delivery times give the largest total profit.	Medium7	Dynamic programmingIntervals	No attempts yet	1s	128 MB	Judgeable
SojuGiven two point sets with every point of the first west of every point of the second, find the smallest Manhattan distance between a point from each set.	Medium7	GeometrySorting	No attempts yet	3s	128 MB	Judgeable
Popping GroupsDecide whether a string of a and b can be fully erased by repeatedly deleting maximal runs of at least two equal letters.	Medium7	Dynamic programmingString+1	No attempts yet	2s	128 MB	Judgeable
MinesTrigger the fewest mines so chain reactions through overlapping blast squares detonate all N mines.	Medium7	GraphDFS+1	No attempts yet	1s	128 MB	Judgeable
Tour BeltFor each test case the program sums the sizes of connected island groups whose weakest inner synergy beats every outgoing synergy.	Medium7	Minimum spanning treeUnion-find+1	No attempts yet	1s	128 MB	Judgeable
AirportThe tower serves one of two waiting lines at each time to minimize the worst waiting position any aircraft receives.	Medium7	Binary searchGreedy+1	No attempts yet	1s	128 MB	Judgeable
GC-RatioFind the contiguous segment of length at least L with the largest share of ones, breaking ties by shorter length then earlier start.	Medium7	Binary searchPrefix sum	No attempts yet	2s	128 MB	Judgeable