Problems

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Total results29,440 problems

Hold the Line!
Medium7
Array, Segment tree+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Elections
Medium7
Sliding window, Sorting+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Tourist Agency
Medium7
Sliding window, Segment tree+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Madness
Medium7
Matrix, String matching+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Coin Game
Medium7
Game theory, Math+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Siege
Medium7
Binary search, Number theory+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Christmas Tree
Medium7
Tree, DFS
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Pine is a tree
Medium7
Tree, Dynamic programming+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Graph decomposition
Medium7
Graph, Combinatorics+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Bloxx city game
Medium7
Dynamic programming, Bit manipulation+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Strange Digits
Medium7
Dynamic programming, Math+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
String Covering
Medium7
String matching, Dynamic programming
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Coin Tower Game
Medium7
Game theory, Dynamic programming
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Nested Collider Systems
Medium7
Combinatorics, Dynamic programming+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Cruel games
Medium7
Geometry, Brute force+1
No attempts yet
Time limit
5s
Memory limit
1024 MB
Judgeable
Labyrinth
Medium7
Shortest path, Graph+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Hot Potato Routing
Medium7
Simulation, Graph+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Number Guessing Game
Medium7
Game theory, Dynamic programming+1
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Triangles
Medium7
Geometry, Implementation+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Code lock
Medium7
Bit manipulation, BFS+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Hey! That's My Fish!
Medium7
Game theory, Dynamic programming+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Base Defense
Medium7
Dynamic programming, Matrix+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Making Strings
Medium7
Dynamic programming, Math+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Coreputer
Medium7
Bit manipulation, Divide and conquer+1
No attempts yet
Time limit
0.5s
Memory limit
1024 MB
Judgeable
Water Spreading
Medium7
BFS, Graph+1
No attempts yet
Time limit
2.5s
Memory limit
1024 MB
Judgeable
Digit Short Coding
Medium7
Dynamic programming, Math+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Soldier distribution
Medium7
Dynamic programming, Greedy+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Collecting Pancakes
Medium7
Game theory, Dynamic programming+1
No attempts yet
Time limit
30s
Memory limit
1024 MB
Judgeable
Regular Boss Hunting
Medium7
Dynamic programming, Bit manipulation+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Evolutionary Algorithms
Medium7
Tree, DFS+2
No attempts yet
Time limit
40s
Memory limit
1024 MB
Judgeable
Power Generation Device
Medium7
Combinatorics, Math+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Safe Trading (Hard)
Medium7
Matrix, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Two Pointers (hard version)
Medium7
Dynamic programming, Segment tree
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Clothesline
Medium7
Tree, String+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Partitions
Medium7
Segment tree, Sorting+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Final Round Invitation
Medium7
Sorting, Dynamic programming+1
No attempts yet
Time limit
1.5s
Memory limit
1024 MB
Judgeable
Card Game
Medium7
Segment tree, Prefix sum+1
No attempts yet
Time limit
0.3s
Memory limit
1024 MB
Judgeable
Choice
Medium7
Tree, Game theory+1
No attempts yet
Time limit
10s
Memory limit
1024 MB
Judgeable
Counting Triangles
Medium7
Geometry, Sorting+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Balanced bracket strings
Medium7
Prefix sum, String+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Sequence Deletion
Medium7
Greedy, Array+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
City
Medium7
Greedy, Segment tree+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
MAX Elements
Medium7
Dynamic programming, Tree+2
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
How to Avoid Disqualification in 75 Easy Steps
Medium7
Bit manipulation, Combinatorics+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Constellations
Medium7
Union-find, Sorting+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Boxers
Medium7
Graph, Sorting+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Lelud
Medium7
Divide and conquer, Sorting+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Clothing Stores
Medium7
Array, Segment tree+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Artillery
Medium7
Combinatorics, Math+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
A Boring Lesson with Four Squares
Medium7
Math, Combinatorics
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
How many possibilities?
Medium7
Dynamic programming, Math+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Neutrino Radar
Medium7
Number theory, Math+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Delivery robots
Medium7
Graph, DFS+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Rally in Deep Space
Medium7
Minimum spanning tree, Tree+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Tolled Road Segments
Medium7
Graph, Shortest path
No attempts yet
Time limit
4s
Memory limit
1024 MB
Judgeable
Painting Eggs
Medium7
Segment tree, Implementation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Safe
Medium7
Stack, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Qualifying Contest
Medium7
Greedy, Heap+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Extracting Pollen
Medium7
Heap, Simulation+1
No attempts yet
Time limit
0.5s
Memory limit
1024 MB
Judgeable
Xorshift+ prediction
Medium7
Bit manipulation, Math+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Angles of Overlapping Polygons
Medium7
Geometry, Math+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Dimensional Gate
Medium7
Union-find, Greedy+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Secret Garden
Medium7
Math, Sorting+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Tree and Queries 10^{9}
Medium7
Hash map, Tree+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Why Work?
Medium7
Math, Greedy+1
No attempts yet
Time limit
1.122s
Memory limit
1122 MB
Judgeable
Astronaut Jeongmin
Medium7
BFS, Simulation+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
GCD SUM
Medium7
Segment tree, Number theory+1
No attempts yet
Time limit
5s
Memory limit
1024 MB
Judgeable
Walking Through the Tree
Medium7
Tree, Dynamic programming+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Treasure Chests
Medium7
Dynamic programming, Segment tree+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Guess the Number!
Medium7
Game theory, Binary search
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Map Restoration
Medium7
Graph, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Geometry Problem
Medium7
Geometry, Math
No attempts yet
Time limit
4s
Memory limit
1024 MB
Judgeable
Blocks for Kids
Medium7
Dynamic programming, Math+1
No attempts yet
Time limit
5s
Memory limit
1024 MB
Judgeable
Pile it down
Medium7
Game theory, Dynamic programming
No attempts yet
Time limit
6s
Memory limit
1024 MB
Judgeable
Advise National Security!
Medium7
Dynamic programming, Bit manipulation+1
No attempts yet
Time limit
10s
Memory limit
1024 MB
Judgeable
Shopping Rush
Medium7
Dynamic programming, Sorting+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Chemicals
Medium7
Graph, Dynamic programming+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Animesh does not gift Malvika on her birthday
Medium7
Graph, Combinatorics+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Animesh has a war with tribal leader Malvika
Medium7
Greedy, Combinatorics+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Maximum Sine
Medium7
Math, Number theory
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Jaemin's Birthday
Medium7
Matrix, Two pointers+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Remove K Bars from a Histogram
Medium7
Array, Dynamic programming+1
No attempts yet
Time limit
6s
Memory limit
1024 MB
Judgeable
Apple Banana Tree
Medium7
Tree, Dynamic programming+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Equalize the graph with neighbor pair updates
Medium7
Union-find, Graph+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Spinning Water Cannons
Medium7
Simulation, Geometry+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Dining Hall Support Dispatch
Medium7
Simulation, Greedy+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Trench Warfare
Medium7
Sliding window, Binary search+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Dormitory Construction
Medium7
Two pointers, Math+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Drake Robbing
Medium7
Divide and conquer, Math+1
No attempts yet
Time limit
5s
Memory limit
1024 MB
Judgeable
Bad Bunny
Medium7
Graph, DFS+1
No attempts yet
Time limit
6s
Memory limit
1024 MB
Judgeable
Airplanes
Medium7
Tree, Segment tree+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Ones
Medium7
Number theory, Math+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Fortification
Medium7
Graph, Shortest path+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Television
Medium7
Greedy, Sorting+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Irreducible Permutation
Medium7
Greedy, Array+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Good Triangle
Medium7
Geometry, Combinatorics+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Sleeping Chameleons
Medium7
Shortest path, Graph+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Swapping Brackets
Medium7
Dynamic programming, Combinatorics+1
No attempts yet
Time limit
1.5s
Memory limit
1024 MB
Judgeable
Roulette
Medium7
Dynamic programming, Probability+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Card game
Medium7
Game theory, Dynamic programming+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable

Title	Level	Topics	Solved	Time limit	Memory limit	Judge
Hold the Line!Soldiers start sorted by height, and each command reverses the segment between the a-th and b-th shortest soldiers. Output the final height rank at each position.	Medium7	ArraySegment tree+1	No attempts yet	2s	1024 MB	Judgeable
ElectionsGiven n candidate votes and m range queries, report a candidate with the highest vote count inside each range [l, r].	Medium7	Sliding windowSorting+1	No attempts yet	2s	1024 MB	Judgeable
Tourist AgencyFor each query [l, r], find the longest run of consecutive sights inside that range where no two sights share a type.	Medium7	Sliding windowSegment tree+1	No attempts yet	2s	1024 MB	Judgeable
MadnessGiven apartment ids and lit windows on a grid, find the fewest apartments to change so a target lit/dark pattern appears as a sub-rectangle.	Medium7	MatrixString matching+1	No attempts yet	2s	1024 MB	Judgeable
Coin GameAnn and Betty flip coins on an m by n grid under a Wythoff-style rule. Decide the winner and print Ann's first winning move if one exists.	Medium7	Game theoryMath+1	No attempts yet	2s	1024 MB	Judgeable
SiegeFind the first day on which the distinct attack days exceed k, given n armies that attack on a_i and then every b_i days.	Medium7	Binary searchNumber theory+1	No attempts yet	2s	1024 MB	Judgeable
Christmas TreeGiven N branch lengths and the height differences between consecutive branches, the task answers M queries about the pair of branches numbered i and k.	Medium7	TreeDFS	No attempts yet	2s	1024 MB	Judgeable
Pine is a treeGiven a tree with up to 100000 vertices, find the minimum level of a pine structure it can be built as, where a pine is a trunk path with attached smaller pines.	Medium7	TreeDynamic programming+1	No attempts yet	2s	1024 MB	Judgeable
Graph decompositionGiven n and a partition of 2n-1 into parts a_i, output edge sets of K_{2n} so that each set is an a_i-factor and every edge appears in exactly one set.	Medium7	GraphCombinatorics+1	No attempts yet	2s	1024 MB	Judgeable
Bloxx city gameGiven a grid of existing houses (heights 0 to 5), add houses so the total height is maximized, and print the build order.	Medium7	Dynamic programmingBit manipulation+1	No attempts yet	2s	1024 MB	Judgeable
Strange DigitsGiven a base b, an allowed digit set, and a decimal n up to 10^100, decide whether n has no representation, exactly one, or more than one.	Medium7	Dynamic programmingMath+1	No attempts yet	2s	1024 MB	Judgeable
String CoveringFor each prefix of a string w, find the length of the shortest string whose occurrences together cover every position of that prefix.	Medium7	String matchingDynamic programming	No attempts yet	2s	1024 MB	Judgeable
Coin Tower GameTwo players take coins from two towers, and the one who takes the last coin gains or loses K coins. Find whether Yeongdo should move first or second to win.	Medium7	Game theoryDynamic programming	No attempts yet	1s	512 MB	Judgeable
Nested Collider SystemsCount nested chains of integer-centered circles that fit inside an axis-aligned rectangle of half-sides n and m, modulo 10^9.	Medium7	CombinatoricsDynamic programming+1	No attempts yet	2s	1024 MB	Judgeable
Cruel gamesAlice picks a point off every obstacle line so that the worst-case number of segments blocking her view of Bob, over all his positions, is minimized.	Medium7	GeometryBrute force+1	No attempts yet	5s	1024 MB	Judgeable
LabyrinthGiven a directed graph whose edges carry words of up to 10 letters, find the lexicographically smallest shortest path label from s to t.	Medium7	Shortest pathGraph+1	No attempts yet	2s	1024 MB	Judgeable
Hot Potato RoutingChoose the largest set of packets that all reach their destinations on fixed node schedules, with no two packets at the same node in the same tick.	Medium7	SimulationGraph+1	No attempts yet	2s	1024 MB	Judgeable
Number Guessing GameFor each N from 1 to M, find the first questions student 1 can ask to maximize their own winning chance, given K students playing the guessing game.	Medium7	Game theoryDynamic programming+1	No attempts yet	3s	512 MB	Judgeable
TrianglesEach step replaces every triangle with its medial-triangle expansion, and the task is to find the first step where some pair of triangles intersects.	Medium7	GeometryImplementation+1	No attempts yet	2s	1024 MB	Judgeable
Code lockCount the connected sets of exactly k button cells on a grid of up to 30 by 30 cells, where cells sharing a side connect.	Medium7	Bit manipulationBFS+1	No attempts yet	2s	1024 MB	Judgeable
Hey! That's My Fish!Two players place penguins on a row of fish cards and take turns moving them, maximizing their fish difference. Find the first player's best result.	Medium7	Game theoryDynamic programming+1	No attempts yet	2s	1024 MB	Judgeable
Base DefenseGiven F formations and each day's fixed last formation, find the minimum total squared-difference fatigue over L days of T changes each.	Medium7	Dynamic programmingMatrix+1	No attempts yet	1s	1024 MB	Judgeable
Making StringsGiven character sets grouped by weight from 1 to 9, count the strings whose total weight lies between a and b, modulo 1,000,000,007.	Medium7	Dynamic programmingMath+1	No attempts yet	1s	1024 MB	Judgeable
CoreputerFind all malfunctioning cores among N up to 16 by asking which of two groups has more bad cores, using an adaptive query protocol.	Medium7	Bit manipulationDivide and conquer+1	No attempts yet	0.5s	1024 MB	Judgeable
Water SpreadingGiven an N by N grid of heights and a starting cell with state X, count the cells that get water as it spreads to equal-height and lower neighbors.	Medium7	BFSGraph+1	No attempts yet	2.5s	1024 MB	Judgeable
Digit Short CodingGiven N up to 10^8, find the shortest postfix expression of digits, * and ^ that evaluates to N.	Medium7	Dynamic programmingMath+1	No attempts yet	1s	1024 MB	Judgeable
Soldier distributionAssign each of N soldiers to generals A, B, or C so that every general gets at least K soldiers, and find the maximum total ability value.	Medium7	Dynamic programmingGreedy+1	No attempts yet	1s	1024 MB	Judgeable
Collecting PancakesAlice and Bob take turns claiming adjacent stacks on a line after their opening picks; find the most pancakes Alice can get with optimal play.	Medium7	Game theoryDynamic programming+1	No attempts yet	30s	1024 MB	Judgeable
Regular Boss HuntingChoose at most M of N characters, each hunting for 15 minutes a day, and assign K bosses to them so the total meso from defeated bosses is maximized.	Medium7	Dynamic programmingBit manipulation+1	No attempts yet	1s	1024 MB	Judgeable
Evolutionary AlgorithmsCount ordered triplets (a, b, c) where b is an ancestor of a but not of c, and S_b is at least K times both S_a and S_c plus 1.	Medium7	TreeDFS+2	No attempts yet	40s	1024 MB	Judgeable
Power Generation DeviceGiven a pyramid whose edge modules follow an arithmetic speed sequence, compute the value at each queried (R, C) modulo 1e9+7 for up to 2 x 10^5 queries.	Medium7	CombinatoricsMath+1	No attempts yet	1s	1024 MB	Judgeable
Safe Trading (Hard)Given balances on days 0 to p-1 and a linear threshold recurrence, find the minimum balance on day k (up to 1e18) modulo 1e9+7.	Medium7	MatrixMath	No attempts yet	1s	1024 MB	Judgeable
Two Pointers (hard version)Alice and Bob must visit n events in order, each taken by one of them, and the task is to find the minimum total distance they drive.	Medium7	Dynamic programmingSegment tree	No attempts yet	2s	1024 MB	Judgeable
ClotheslineGiven a string of three shirt colors, answer per-color counts on ranges while moving segments to the front or back and reversing segments.	Medium7	TreeString+1	No attempts yet	2s	1024 MB	Judgeable
PartitionsGiven N non-overlapping axis-parallel rectangles, find the total length of boundary segments where two rectangles share an edge.	Medium7	Segment treeSorting+1	No attempts yet	1s	1024 MB	Judgeable
Final Round InvitationCount the ways to choose a nonempty set of students so that each invited student beats every uninvited student in at least one contest, modulo 1000000007.	Medium7	SortingDynamic programming+1	No attempts yet	1.5s	1024 MB	Judgeable
Card GameFind the least possible maximum hand size when picking up cards from a circle of 3N cards, and list every starting card that achieves it.	Medium7	Segment treePrefix sum+1	No attempts yet	0.3s	1024 MB	Judgeable
ChoiceAntek and Borys alternately persuade ordinary employees in a majority-vote tree; find the employees Antek should pick so apples win.	Medium7	TreeGame theory+1	No attempts yet	10s	1024 MB	Judgeable
Counting TrianglesGiven N line segments with integer endpoints, count the triangles whose three sides are three of the segments, excluding degenerate ones.	Medium7	GeometrySorting+1	No attempts yet	3s	1024 MB	Judgeable
Balanced bracket stringsGiven a bracket string and queries (L, R), decide whether some split point k inside (L, R) divides A[L..R] into two balanced bracket strings.	Medium7	Prefix sumString+1	No attempts yet	2s	1024 MB	Judgeable
Sequence DeletionSplit sequence A into consecutive blocks so that the list of block mex values is lexicographically maximum, then print that list B.	Medium7	GreedyArray+1	No attempts yet	2s	1024 MB	Judgeable
CityAssign distinct heights 1 to N to N buildings so that at least M-1 of the M segment minimum-height requirements hold, or report that no plan exists.	Medium7	GreedySegment tree+1	No attempts yet	3s	1024 MB	Judgeable
MAX ElementsGiven a binary tree with values on its leaves, find the fewest MAX nodes needed so the root reaches each query value M, or -1 if impossible.	Medium7	Dynamic programmingTree+2	No attempts yet	3s	1024 MB	Judgeable
How to Avoid Disqualification in 75 Easy StepsFind two chairmen among 1000 positions using R robots that each send one yes/no report about a chosen set of positions, within H hours.	Medium7	Bit manipulationCombinatorics+1	No attempts yet	1s	1024 MB	Judgeable
ConstellationsGiven a weighted graph, pick a threshold K so that the count of path components minus cycle components is as close to zero as possible, choosing the smallest K on ties.	Medium7	Union-findSorting+2	No attempts yet	1s	1024 MB	Judgeable
BoxersGiven a round-robin tournament of N boxers, find two boxers whose removal leaves results that match one strict strength order.	Medium7	GraphSorting+1	No attempts yet	1s	1024 MB	Judgeable
LeludRecover the hidden preference ranking of N toys by asking which toy is the median of an odd-sized set of toys, within a limited number of queries.	Medium7	Divide and conquerSorting+1	No attempts yet	1s	1024 MB	Judgeable
Clothing StoresPrices are non-increasing. Handle prefix updates that raise prices to at least Y, and count suits bought greedily from store X with budget Y.	Medium7	ArraySegment tree+1	No attempts yet	1s	1024 MB	Judgeable
ArtilleryFind the maximum sum of distances between consecutive shots, how many firing orders reach it mod 1e9+7, and the first and M-th such orders.	Medium7	CombinatoricsMath+1	No attempts yet	1s	1024 MB	Judgeable
A Boring Lesson with Four SquaresCount the ways to place four non-overlapping squares, one in each corner of an M by N sheet, modulo 1e9+7.	Medium7	MathCombinatorics	No attempts yet	1s	1024 MB	Judgeable
How many possibilities?Count the key press sequences on a staggered N by N keyboard where consecutive pressed keys are at the given distances, modulo 1e9+7.	Medium7	Dynamic programmingMath+1	No attempts yet	2s	1024 MB	Judgeable
Neutrino RadarFind the index A of the habitable planet among N planets using at most 40 calls to Scan(X, Y), which returns gcd(X, A+Y).	Medium7	Number theoryMath+1	No attempts yet	1s	1024 MB	Judgeable
Delivery robotsGiven a connected undirected graph, find the largest number of vertices that can lie on simple paths from a chosen start s to a chosen end f.	Medium7	GraphDFS+1	No attempts yet	1s	1024 MB	Judgeable
Rally in Deep SpaceFor each query of two checkpoints, find the minimum sum of 2^k over the courses on a path, where k is the course's speed, modulo 10^9+7.	Medium7	Minimum spanning treeTree+2	No attempts yet	1s	1024 MB	Judgeable
Tolled Road SegmentsFind the largest total toll on the main highway segments so that no driver prefers a side-road detour.	Medium7	GraphShortest path	No attempts yet	4s	1024 MB	Judgeable
Painting EggsGiven N eggs in a row, process paint, remove, and color-query operations, and report the longest run of unpainted eggs after each L query.	Medium7	Segment treeImplementation	No attempts yet	2s	1024 MB	Judgeable
SafeTwo equal-length numbers get digits appended and removed from the right, and each query asks for one digit of their sum.	Medium7	StackMath	No attempts yet	1s	1024 MB	Judgeable
Qualifying ContestChoose tasks within time T to maximize the count of solved tasks whose difficulty A_i is at least the total solved count, breaking ties by finish time.	Medium7	GreedyHeap+1	No attempts yet	1s	1024 MB	Judgeable
Extracting PollenGiven N flowers with pollen counts, each bee takes the digit sum from a currently largest flower; find the amount collected by the K-th bee.	Medium7	HeapSimulation+1	No attempts yet	0.5s	1024 MB	Judgeable
Xorshift+ predictionGiven K consecutive outputs of a xorshift+ style generator with known shifts, the task is to predict the next returned value.	Medium7	Bit manipulationMath+1	No attempts yet	1s	1024 MB	Judgeable
Angles of Overlapping PolygonsGiven nested convex polygons with non-increasing vertex counts A_i, find the maximum sum of counted angles in a valid figure.	Medium7	GeometryMath+1	No attempts yet	1s	1024 MB	Judgeable
Dimensional GateGiven a permutation, find the cheapest swaps (cost is the squared gap between swapped gate numbers) that merge all cycles into one.	Medium7	Union-findGreedy+2	No attempts yet	1s	1024 MB	Judgeable
Secret GardenGiven K planted cells in an N by M grid, find the fewest days until every cell is within Manhattan distance of a flower.	Medium7	MathSorting+1	No attempts yet	1s	1024 MB	Judgeable
Tree and Queries 10^{9}Given an infinite perfect binary tree, process queries that move a subtree under a new parent and print the sum of vertex numbers on the path between two vertices.	Medium7	Hash mapTree+1	No attempts yet	2s	1024 MB	Judgeable
Why Work?Given N coins whose prices follow a binary-counter-like update rule, find the maximum profit from trading one unit per coin per day over T days.	Medium7	MathGreedy+1	No attempts yet	1.122s	1122 MB	Judgeable
Astronaut JeongminFind the fewest seconds for Jeongmin to reach the spaceship cell across two grids while avoiding black holes that spread along the airflow.	Medium7	BFSSimulation+1	No attempts yet	1s	1024 MB	Judgeable
GCD SUMGiven an array, answer online range queries that ask for the sum of gcd over every contiguous subarray inside the range [l, r], with l and r XOR-encoded by the previous answer.	Medium7	Segment treeNumber theory+1	No attempts yet	5s	1024 MB	Judgeable
Walking Through the TreeCount the cyclic orders of all N tree vertices where no middle vertex lies on the tree path between its two neighbors, modulo 998244353.	Medium7	TreeDynamic programming+1	No attempts yet	1s	1024 MB	Judgeable
Treasure ChestsFor each i from 1 to K, find the largest count of distinct integers covered by the union of exactly i chosen intervals out of N.	Medium7	Dynamic programmingSegment tree+1	No attempts yet	2s	1024 MB	Judgeable
Guess the Number!Vytautas guesses a number from 1 to N against Artūras, who may adapt his secret number as long as his answers never contradict each other, and Vytautas must finish with at least as many points.	Medium7	Game theoryBinary search	No attempts yet	1s	1024 MB	Judgeable
Map RestorationGiven a 3-regular graph made by expanding each original intersection into a gadget, count the original intersections of each degree from 1 to 5.	Medium7	GraphImplementation	No attempts yet	1s	1024 MB	Judgeable
Geometry ProblemGiven two triangles with integer vertices and constant velocities, find the earliest time they collide, or report NO COLLISION if they never touch.	Medium7	GeometryMath	No attempts yet	4s	1024 MB	Judgeable
Blocks for KidsCount the ways to cut a 2xN Pango board into two tileable boards at some point k, modulo 10007, for up to 300 values of N up to 1e9.	Medium7	Dynamic programmingMath+1	No attempts yet	5s	1024 MB	Judgeable
Pile it downTwo piles of X and Y coins are played with removal moves and at most P passes; output the winner and the total number of moves under optimal play.	Medium7	Game theoryDynamic programming	No attempts yet	6s	1024 MB	Judgeable
Advise National Security!Given camera watch links along a highway, find the fewest minutes two terrorists need to destroy every camera without being caught.	Medium7	Dynamic programmingBit manipulation+1	No attempts yet	10s	1024 MB	Judgeable
Shopping RushPlace N gifts on distinct floors to minimize the expected travel time between two independent gift picks, and print the minimum as a reduced fraction.	Medium7	Dynamic programmingSorting+1	No attempts yet	1s	1024 MB	Judgeable
ChemicalsCount the ways to split N chemicals into K distinct nonempty boxes so that no box holds a pair where one chemical explodes with its partner C[i].	Medium7	GraphDynamic programming+1	No attempts yet	1s	1024 MB	Judgeable
Animesh does not gift Malvika on her birthdayGiven a graph G on n vertices where every vertex misses at most 2 neighbors, count the labeled graphs that are isomorphic to G.	Medium7	GraphCombinatorics+1	No attempts yet	1s	1024 MB	Judgeable
Animesh has a war with tribal leader MalvikaCount the soldier arrangements that maximize the sum of position distances between same-tribe pairs, modulo 1e9+7.	Medium7	GreedyCombinatorics+2	No attempts yet	1s	1024 MB	Judgeable
Maximum SineGiven a, b, p, and q, find the smallest integer x in [a, b] that maximizes \|sin(p/q * pi * x)\| across multiple test cases.	Medium7	MathNumber theory	No attempts yet	3s	1024 MB	Judgeable
Jaemin's BirthdayGiven an H by W grid of sweetness values, find the rectangle of exactly N cells whose max minus min is largest, or report -1 if no such rectangle exists.	Medium7	MatrixTwo pointers+1	No attempts yet	3s	1024 MB	Judgeable
Remove K Bars from a HistogramGiven N histogram bars, find for each K from 0 to N-1 the largest rectangle area left after removing exactly K bars.	Medium7	ArrayDynamic programming+1	No attempts yet	6s	1024 MB	Judgeable
Apple Banana TreeGiven a tree whose vertices are labeled A or B, find the fewest edge swaps that make each label form one connected subgraph, or -1.	Medium7	TreeDynamic programming+1	No attempts yet	1s	1024 MB	Judgeable
Equalize the graph with neighbor pair updatesDecide whether repeatedly adding k to two neighbors of one vertex can make every vertex hold the same value.	Medium7	Union-findGraph+1	No attempts yet	2s	1024 MB	Judgeable
Spinning Water CannonsGiven N cannons on a circle that rotate and fire jets at fixed periods, find every participant position that is guaranteed to survive until the game ends.	Medium7	SimulationGeometry+1	No attempts yet	1s	1024 MB	Judgeable
Dining Hall Support DispatchGiven a day d and a soldier number x, find how many times the dispatch program picks soldier x through day d.	Medium7	SimulationGreedy+1	No attempts yet	1s	1024 MB	Judgeable
Trench WarfareChoose one contiguous range of trenches whose enemy total is at most K to bomb, then win as many other trenches as M soldiers allow.	Medium7	Sliding windowBinary search+1	No attempts yet	1s	1024 MB	Judgeable
Dormitory ConstructionFor each query [l, r], find the longest run of plots that can be leveled to one height with at most M soldiers, where a change of x costs x^2.	Medium7	Two pointersMath+1	No attempts yet	2s	1024 MB	Judgeable
Drake RobbingGiven n treasure types with huge counts, choose how many of each to carry under a volume limit V to maximize total worth.	Medium7	Divide and conquerMath+1	No attempts yet	5s	1024 MB	Judgeable
Bad BunnyGiven a connected graph and many queries (s, d), count the clearings that lie on every path from s to d, including s and d.	Medium7	GraphDFS+1	No attempts yet	6s	1024 MB	Judgeable
AirplanesGiven transfers forming a tree, where each landing time is the max of its schedule and its feeders' times, answer landing-time queries under delay updates.	Medium7	TreeSegment tree+1	No attempts yet	1s	1024 MB	Judgeable
OnesGiven N ones and a repdigit of M copies of digit d, divide the first by the second and output the digit sum of the quotient, or NESIDALO if it is not an integer.	Medium7	Number theoryMath+1	No attempts yet	1s	1024 MB	Judgeable
FortificationGiven fortification times for locations and roads that flood at set times, find the most locations that can be fortified on a round trip starting and ending at location 1.	Medium7	GraphShortest path+1	No attempts yet	2s	1024 MB	Judgeable
TelevisionGiven broadcasts with air times, a memory of V seconds, and K recording slots, find the earliest time all can be watched in order, or report NEGALIMA.	Medium7	GreedySorting+1	No attempts yet	1s	1024 MB	Judgeable
Irreducible PermutationGiven a permutation, find the fewest adjacent swaps that leave no proper prefix as a permutation, and print the swap sequence.	Medium7	GreedyArray+1	No attempts yet	1s	1024 MB	Judgeable
Good TriangleCount the triples of distinct points for which some point T is equidistant from all three under Manhattan distance, with up to 500000 points.	Medium7	GeometryCombinatorics+1	No attempts yet	2s	1024 MB	Judgeable
Sleeping ChameleonsFind the minimum seconds to wake chameleon N starting from chameleon 1, where king moves cost 1 and free tongue reaches cannot link same-colored chameleons.	Medium7	Shortest pathGraph+1	No attempts yet	1s	1024 MB	Judgeable
Swapping BracketsCount the nonempty position sets S where rearranging the brackets inside S can turn the sequence into a proper bracket sequence, modulo 998244353.	Medium7	Dynamic programmingCombinatorics+1	No attempts yet	1.5s	1024 MB	Judgeable
RouletteAlbums cost A_i won for B_i tickets each, and each re-spin costs R won; find the minimum expected cost to guarantee a win as a reduced fraction.	Medium7	Dynamic programmingProbability+1	No attempts yet	1s	1024 MB	Judgeable
Card gameAdam chooses each round whether to show or keep his card so that he wins the N-round game by the largest possible point margin.	Medium7	Game theoryDynamic programming+1	No attempts yet	1s	1024 MB	Judgeable