Problems

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Total results29,275 problems

Water Pipe Game
Hard8
Game theory, Graph+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Necklaces
Hard8
Sorting, Binary search+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Energy Generation
Hard8
Graph, Geometry
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Greedy Knapsack
Hard8
Greedy, Simulation+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Greatest Common Divisor
Hard8
Number theory, Math+1
No attempts yet
Time limit
5s
Memory limit
1024 MB
Judgeable
Meeting Point
Hard8
Tree, Divide and conquer+1
No attempts yet
Time limit
25s
Memory limit
1024 MB
Judgeable
Train Trip
Hard8
Graph, Greedy+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Breakdown
Hard8
Dynamic programming, Shortest path+2
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
TwoFour
Hard8
Game theory, Dynamic programming+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Image Correction Task
Hard8
Binary search, Graph
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Attack Relay
Hard8
Simulation, Geometry+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Concert for the Troops
Hard8
Array, Segment tree+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Brue Marble
Hard8
Graph, Dynamic programming+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Procurement Optimization
Hard8
Tree, Dynamic programming+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Projectors
Hard8
Geometry, Sorting+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Expedition to Sirius
Hard8
Sorting, Prefix sum+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Magnetic Games
Hard8
Implementation, Geometry+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Square Running
Hard8
Number theory, Math+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
GPS Hack
Hard8
Shortest path, Dynamic programming+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Bob's Average
Hard8
Binary search, Prefix sum+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Wires Puzzle
Hard8
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
JOIG Tour
Hard8
Dynamic programming, Segment tree
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Stacking Cups
Hard8
Dynamic programming, Combinatorics
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Jump Rope
Hard8
Geometry, Sorting+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Precise Map Construction
Hard8
Binary search, Two pointers+2
No attempts yet
Time limit
2.5s
Memory limit
1024 MB
Judgeable
Letter Delivery 2
Hard8
Segment tree, Binary search+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Dragonfly
Hard8
Tree, DFS+1
No attempts yet
Time limit
5s
Memory limit
1024 MB
Judgeable
Voting Cities
Hard8
Shortest path, Bit manipulation+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Grapevine
Hard8
Tree, Divide and conquer+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Fruits
Hard8
Dynamic programming, Greedy
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Digital XOR
Hard8
Bit manipulation, Implementation+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
How Much Money Can Eggs Make?
Hard8
Combinatorics, Math+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
DAGame
Hard8
Game theory, Dynamic programming+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Chino's Latte Art
Hard8
Geometry, String matching+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Tax Evasion
Hard8
Tree, Dynamic programming+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Gardening
Hard8
Implementation, Graph
No attempts yet
Time limit
0.2s
Memory limit
1024 MB
Judgeable
Present
Hard8
Number theory, Combinatorics+1
No attempts yet
Time limit
4s
Memory limit
1024 MB
Judgeable
Speedrun
Hard8
Tree, DFS+1
No attempts yet
Time limit
10s
Memory limit
1024 MB
Judgeable
Paths
Hard8
Tree, Dynamic programming+1
No attempts yet
Time limit
0.3s
Memory limit
1024 MB
Judgeable
Weirdtree
Hard8
Segment tree, Simulation
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Letter Passing
Hard8
Number theory, Math+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Floppy
Hard8
Tree, Stack+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Peru
Hard8
Dynamic programming, Sliding window+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Nice Lines
Hard8
Geometry, Math+1
No attempts yet
Time limit
0.2s
Memory limit
1024 MB
Judgeable
Colorful Tree
Hard8
Tree, Dynamic programming+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Birthday Gift
Hard8
Dynamic programming, Matrix+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Fishing Game
Hard8
Dynamic programming, Combinatorics
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Chimichangas
Hard8
Math, Dynamic programming+1
No attempts yet
Time limit
0.35s
Memory limit
1024 MB
Judgeable
Euclid
Hard8
Segment tree, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Cake Decoration
Hard8
Math, Combinatorics+1
No attempts yet
Time limit
10s
Memory limit
1024 MB
Judgeable
Sorting
Hard8
Combinatorics, Dynamic programming+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Game With Numbers
Hard8
Game theory, Number theory+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Pancake Tower
Hard8
Probability, Combinatorics+1
No attempts yet
Time limit
0.7s
Memory limit
1024 MB
Judgeable
Graph Traveler
Hard8
Graph, Union-find+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
K-Convex Hull
Hard8
Geometry, Sorting+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Sinchon Defense HQ Escape
Hard8
Graph, Shortest path+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Listening Test Practice
Hard8
String matching, Sorting+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Fencing the Sheep
Hard8
Geometry, Sorting+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
UFO in the Sinchon
Hard8
Math, Simulation+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Making a Good Binary String
Hard8
Prefix sum, Dynamic programming+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Cat Exercise
Hard8
Tree, Dynamic programming+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Modern Machine
Hard8
Simulation, Segment tree+1
No attempts yet
Time limit
2.5s
Memory limit
1024 MB
Judgeable
Tractor Paths
Hard8
Graph, Shortest path+1
No attempts yet
Time limit
4s
Memory limit
1024 MB
Judgeable
Subtree Activation
Hard8
Tree, Dynamic programming+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Branch Manager
Hard8
Tree, Greedy+1
No attempts yet
Time limit
4s
Memory limit
1024 MB
Judgeable
Digits of Unity
Hard8
Bit manipulation, Combinatorics+1
No attempts yet
Time limit
5s
Memory limit
1024 MB
Judgeable
Italian Data Centers
Hard8
Shortest path, Graph+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Base Station Pruning
Hard8
Tree, Divide and conquer+1
No attempts yet
Time limit
4s
Memory limit
1024 MB
Judgeable
Meeting Room 2
Hard8
Dynamic programming, Intervals
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Students
Hard8
Intervals, Sorting+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Team Formation
Hard8
Geometry, Segment tree+2
No attempts yet
Time limit
6s
Memory limit
1024 MB
Judgeable
Hilbert's Hedge Maze
Hard8
Recursion, Divide and conquer+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Forming a Team
Hard8
Segment tree, Sorting+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Convex Hull
Hard8
Geometry, Sorting+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Qizz Quzz (Hard)
Hard8
String, String matching+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Flipping and cutting (Hard)
Hard8
Number theory, Math+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Russian Roulette (Hard)
Hard8
Dynamic programming, Probability+1
No attempts yet
Time limit
5s
Memory limit
1024 MB
Judgeable
Ferries (Hard)
Hard8
Math, Bit manipulation
No attempts yet
Time limit
10s
Memory limit
1024 MB
Judgeable
Ultimate magic rectangles (Hard)
Hard8
Math, Combinatorics+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Dijkstra's Nightmare (Hard)
Hard8
Shortest path, Graph+1
No attempts yet
Time limit
60s
Memory limit
1024 MB
Judgeable
Copier
Hard8
String matching, Greedy+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Maximum enjoyment
Hard8
Graph, Shortest path+1
No attempts yet
Time limit
10s
Memory limit
1024 MB
Judgeable
Exploring the cave
Hard8
Graph, Combinatorics+1
No attempts yet
Time limit
10s
Memory limit
1024 MB
Judgeable
Grid travel
Hard8
Graph, Divide and conquer+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Harvesting potatoes
Hard8
Implementation, Greedy+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Rotate to divide
Hard8
Number theory, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Klingon High Council Training
Hard8
Game theory, Number theory+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Counting Cases
Hard8
Number theory, Dynamic programming+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Forest Scientist
Hard8
Tree, Greedy+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Oil Pipeline II
Hard8
Segment tree, Implementation+1
No attempts yet
Time limit
4s
Memory limit
1024 MB
Judgeable
Operator Party
Hard8
Math, Bit manipulation+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Name-Preserving Network
Hard8
Graph, Implementation
No attempts yet
Time limit
10s
Memory limit
1024 MB
Judgeable
The Cartesian Job
Hard8
Geometry, Probability+1
No attempts yet
Time limit
40s
Memory limit
1024 MB
Judgeable
Robot Programming Strategy
Hard8
String, Greedy+2
No attempts yet
Time limit
20s
Memory limit
1024 MB
Judgeable
Bacterial Tactics
Hard8
Game theory, Graph+1
No attempts yet
Time limit
30s
Memory limit
1024 MB
Judgeable
New Elements: Part 1
Hard8
Geometry, Sorting+1
No attempts yet
Time limit
20s
Memory limit
1024 MB
Judgeable
Pottery Lottery
Hard8
Probability, Game theory+1
No attempts yet
Time limit
40s
Memory limit
1024 MB
Judgeable
Zillionim
Hard8
Game theory, Math+1
No attempts yet
Time limit
50s
Memory limit
1024 MB
Judgeable
Go To Considered Helpful
Hard8
BFS, Graph+1
No attempts yet
Time limit
Not set
Memory limit
1024 MB
Judgeable
Join the Ranks
Hard8
Math, Implementation
No attempts yet
Time limit
Not set
Memory limit
1024 MB
Judgeable

Title	Level	Topics	Solved	Time limit	Memory limit	Judge
Water Pipe GameFor each intersection, decide whether the first player wins the game where crews take turns walking along unused road segments.	Hard8	Game theoryGraph+1	No attempts yet	1s	1024 MB	Judgeable
NecklacesGiven n beads with values, find the k-th subset ordered by total value, with ties broken by the lexicographic order of bead numbers.	Hard8	SortingBinary search+1	No attempts yet	2s	1024 MB	Judgeable
Energy GenerationGiven N towers on a plane, choose each tower's 90-degree orientation to maximize passive energy plus pairwise interaction energy for towers within radius R.	Hard8	GraphGeometry	No attempts yet	1s	1024 MB	Judgeable
Greedy KnapsackGiven N items with weights and values, find the largest total value the greedy packing reaches over every capacity M from 1 to T.	Hard8	GreedySimulation+1	No attempts yet	1s	1024 MB	Judgeable
Greatest Common DivisorGiven n and queries p, find the p-th pair (x, y) in lexicographic order where Gennady's div-based Euclid finishes and outputs the true gcd.	Hard8	Number theoryMath+1	No attempts yet	5s	1024 MB	Judgeable
Meeting PointGiven an odd-sized hidden tree queried only by three-node median (meeting point) queries, find the node minimizing the total distance to all friends.	Hard8	TreeDivide and conquer+1	No attempts yet	25s	1024 MB	Judgeable
Train TripSeat 4N people in an N by 4 grid to maximize the sum of 1/L^2 over friend pairs, where L is the distance between their seats.	Hard8	GraphGreedy+1	No attempts yet	1s	1024 MB	Judgeable
BreakdownGiven a complete directed graph with edges removed one at a time, report the shortest path from node 1 to node N using exactly K edges after each removal.	Hard8	Dynamic programmingShortest path+2	No attempts yet	3s	1024 MB	Judgeable
TwoFourGiven initial piles of 0 to 4 balls, find the winner of TwoFour under optimal play, where each two-ball pile belongs to whoever last moved it.	Hard8	Game theoryDynamic programming+1	No attempts yet	1s	1024 MB	Judgeable
Image Correction TaskGiven a grid of sharpness values, correct at most K cells to the maximum X so the largest difference between adjacent cells is as small as possible.	Hard8	Binary searchGraph	No attempts yet	3s	1024 MB	Judgeable
Attack RelayGiven N members with positions and view directions, find the total damage each member takes over K chase turns, modulo 998244353.	Hard8	SimulationGeometry+1	No attempts yet	3s	1024 MB	Judgeable
Concert for the TroopsGiven a ticket permutation, the task is to sum the total soldier moves over every pair of tickets that could have been swapped.	Hard8	ArraySegment tree+1	No attempts yet	1s	1024 MB	Judgeable
Brue MarbleGiven a grid of arrows and timed point events, find the score after L moves from a start cell, applying events as they are added.	Hard8	GraphDynamic programming+1	No attempts yet	3s	1024 MB	Judgeable
Procurement OptimizationAssign counts to tree vertices so each subtree sum lies in its [l, r] range, minimizing the total cost of counts times prices.	Hard8	TreeDynamic programming+1	No attempts yet	1s	1024 MB	Judgeable
ProjectorsEach projector lights one axis-aligned 90-degree corner of a w by h field; choose the directions that maximize the total lit area.	Hard8	GeometrySorting+1	No attempts yet	1s	1024 MB	Judgeable
Expedition to SiriusGiven players whose experience grows each round by the count of distinct higher levels, answer queries on level count, total gain, or one player's value.	Hard8	SortingPrefix sum+2	No attempts yet	2s	1024 MB	Judgeable
Magnetic GamesGiven the 8-direction compass readings on an n by m grid, find the magnet's cell and the two lines flipped by the anomaly.	Hard8	ImplementationGeometry+1	No attempts yet	1s	1024 MB	Judgeable
Square RunningGiven n runners on concentric lanes around a rectangle, find the earliest second when every runner is in the photographer's row or column, or report -1.	Hard8	Number theoryMath+1	No attempts yet	1s	1024 MB	Judgeable
GPS HackCount the s-to-t routes with total time exactly L, where the hacked GPS may deviate from a shortest path at most once, modulo 1e9+7.	Hard8	Shortest pathDynamic programming+1	No attempts yet	1s	1024 MB	Judgeable
Bob's AverageFor each query on an odd-length subarray, find the largest single value that repeated median-of-three merges can leave behind.	Hard8	Binary searchPrefix sum+1	No attempts yet	3s	1024 MB	Judgeable
Wires PuzzleRecover a hidden permutation that maps right wire labels to left wire labels, using exactly three interactive queries that report which left wires share a right-side group.	Hard8	MathImplementation	No attempts yet	1s	1024 MB	Judgeable
JOIG TourGiven paintings labeled J, O, I, G on a line, find for each query the shortest walk from S that visits a J, an O, an I, and a G painting in that order, then ends at T.	Hard8	Dynamic programmingSegment tree	No attempts yet	1s	1024 MB	Judgeable
Stacking CupsCount the valid stacks of exactly N red and blue cups, where each cup on top sits on two neighbors with at least one red, modulo prime P.	Hard8	Dynamic programmingCombinatorics	No attempts yet	2s	1024 MB	Judgeable
Jump RopeWoo-kyung starts at S among N ropes that translate at constant velocity, and the task is to find the fewest rope crossings needed to end off every rope.	Hard8	GeometrySorting+1	No attempts yet	3s	1024 MB	Judgeable
Precise Map ConstructionFind the smallest t that gives at least Q distinct sets of analyzed roads in which all building intersections are connected.	Hard8	Binary searchTwo pointers+2	No attempts yet	2.5s	1024 MB	Judgeable
Letter Delivery 2Given a walk along a corridor and M student pairs, count for each move how many letters have been delivered by the end of that move.	Hard8	Segment treeBinary search+1	No attempts yet	3s	1024 MB	Judgeable
DragonflyEach dragonfly flies along the unique tree path from pond 1 to its home pond, eating one bug per pond; count the distinct species it eats.	Hard8	TreeDFS+1	No attempts yet	5s	1024 MB	Judgeable
Voting CitiesFor each start city and ticket prices, find the cheapest road path to a voting city, where each of five discount tickets can be used at most once.	Hard8	Shortest pathBit manipulation+1	No attempts yet	1s	1024 MB	Judgeable
GrapevineGiven a weighted tree where joints get toggled as grapes and branch lengths change, find the distance from a joint to the nearest grape-holding joint.	Hard8	TreeDivide and conquer+1	No attempts yet	3s	1024 MB	Judgeable
FruitsGiven fixed sections and fruit costs that rise with tastiness, find for each prefix length k the maximum total cost of fruits Benson collects as tastiness records.	Hard8	Dynamic programmingGreedy	No attempts yet	1s	1024 MB	Judgeable
Digital XORFind two or more 7-segment digit strings (digits 1 to 9) whose digit-wise XOR equals a given N of up to 10000 digits, with the smallest sum and then the smallest product.	Hard8	Bit manipulationImplementation+1	No attempts yet	1s	1024 MB	Judgeable
How Much Money Can Eggs Make?Jaewoo drops i eggs on day i for K days, and the task is to sum the highest floor testable each day, modulo 1000000007, with K up to 10^18.	Hard8	CombinatoricsMath+1	No attempts yet	1s	1024 MB	Judgeable
DAGameTwo players take turns moving tokens along DAG edges, and same-colored token pairs move together once they meet. Output the winner under optimal play.	Hard8	Game theoryDynamic programming+2	No attempts yet	1s	1024 MB	Judgeable
Chino's Latte ArtGiven a simple polygon, decide whether one reflex vertex and one convex vertex form a symmetry axis that splits it into two convex halves.	Hard8	GeometryString matching+1	No attempts yet	1s	1024 MB	Judgeable
Tax EvasionGiven a tree of N accounts with M of them holding 1 gigadollar, find the earliest day Just must pay taxes when ERS investigates adversarially.	Hard8	TreeDynamic programming+1	No attempts yet	2s	1024 MB	Judgeable
GardeningFill an N by M grid with K flower types so each type forms one connected region and every cell has exactly two same-type neighbors, or report NO.	Hard8	ImplementationGraph	No attempts yet	0.2s	1024 MB	Judgeable
PresentGiven K, output the K-th finite set of positive integers that is closed under gcd, counted in Laikan order.	Hard8	Number theoryCombinatorics+1	No attempts yet	4s	1024 MB	Judgeable
SpeedrunMarcel must visit every node of a hidden tree by reading short binary hints stored on the nodes while keeping failed goTo calls under a limit.	Hard8	TreeDFS+1	No attempts yet	10s	1024 MB	Judgeable
PathsFor each vertex as root, find the maximum total edge weight covered by the union of root-to-vertex paths to K chosen vertices in a weighted tree.	Hard8	TreeDynamic programming+1	No attempts yet	0.3s	1024 MB	Judgeable
WeirdtreeGiven N trees, the task handles point assignments, range sum queries, and k cuts that each lower the leftmost tallest tree in a range by 1.	Hard8	Segment treeSimulation	No attempts yet	2s	1024 MB	Judgeable
Letter PassingGiven a permutation F, find the LCM of its cycle lengths, and the smallest LCM reachable by swapping two entries of F.	Hard8	Number theoryMath+1	No attempts yet	2s	512 MB	Judgeable
FloppyEncode an array of distinct integers into a bit sequence so that range-maximum index queries can be answered from the bits alone.	Hard8	TreeStack+1	No attempts yet	1s	1024 MB	Judgeable
PeruFor each prefix of beetles, find the minimum total glove effort needed to crush it, then output the base-23 weighted sum of those values modulo 1e9+7.	Hard8	Dynamic programmingSliding window+1	No attempts yet	1s	1024 MB	Judgeable
Nice LinesRecover the N hidden lines y = a_i x + b_i by querying the sum of distances from a chosen point to all lines, using few queries.	Hard8	GeometryMath+1	No attempts yet	0.2s	1024 MB	Judgeable
Colorful TreeCount the colorings of a rooted tree with k colors where each vertex takes one of its children's colors, and the children use between l_i and r_i colors.	Hard8	TreeDynamic programming+2	No attempts yet	2s	512 MB	Judgeable
Birthday GiftCount the decimal numbers with exactly a digits, no two adjacent digits equal, and remainder b mod 225, modulo 1e9+7.	Hard8	Dynamic programmingMatrix+1	No attempts yet	2s	1024 MB	Judgeable
Fishing GameCount the distinct ways three players can pass cards in Fishing until every card is discarded, given their hands after the first discard, modulo 1000000007.	Hard8	Dynamic programmingCombinatorics	No attempts yet	1s	1024 MB	Judgeable
ChimichangasCount the ordered sequences of exactly K calorie values from N types that sum to each queried meal, modulo 2999.	Hard8	MathDynamic programming+1	No attempts yet	0.35s	1024 MB	Judgeable
EuclidAnswer range gcd queries on an array after range updates that add an arithmetic progression to each interval.	Hard8	Segment treeMath	No attempts yet	1s	1024 MB	Judgeable
Cake DecorationCount distinct positive quadruples (dogs, cats, red, blue) with dogs plus cats in [L, R) whose product is at most X but exceeds X when any single count increases by one.	Hard8	MathCombinatorics+1	No attempts yet	10s	1024 MB	Judgeable
SortingCount permutations of N elements whose inversion count exceeds the minimum number of arbitrary swaps (N minus cycles), modulo 999017.	Hard8	CombinatoricsDynamic programming+1	No attempts yet	1s	1024 MB	Judgeable
Game With NumbersTwo players alternately delete all array elements divisible by b_i or all not divisible by b_i, and the task is the final sum under optimal play.	Hard8	Game theoryNumber theory+1	No attempts yet	1s	1024 MB	Judgeable
Pancake TowerGiven odd N and p/q, find the probability that spoiled pancakes outnumber fresh ones in a chain of N, modulo 998244353.	Hard8	ProbabilityCombinatorics+1	No attempts yet	0.7s	1024 MB	Judgeable
Graph TravelerFor each query start (x, y), count the distinct vertices the walk visits infinitely often, where the next edge depends on the running sum c mod m_i.	Hard8	GraphUnion-find+1	No attempts yet	2s	512 MB	Judgeable
K-Convex HullGiven N distinct points, count how many single points can be removed so that the convex hull of the remaining points has exactly K vertices.	Hard8	GeometrySorting+1	No attempts yet	1s	1024 MB	Judgeable
Sinchon Defense HQ EscapeRoute people from building 1 to exit building N through corridors that catch fire and collapse, maximizing evacuees first, then escape time, then fatigue.	Hard8	GraphShortest path+1	No attempts yet	1s	1024 MB	Judgeable
Listening Test PracticeFor each query, count the substrings of S whose longest common prefix with T[i..j] is exactly k characters.	Hard8	String matchingSorting+1	No attempts yet	3s	1024 MB	Judgeable
Fencing the SheepGiven N sheep on an infinite grid, find the fewest unit fences that enclose all sheep in one connected pen, and the smallest pen area with that many fences.	Hard8	GeometrySorting+1	No attempts yet	1s	1024 MB	Judgeable
UFO in the SinchonEach UFO pulls every person one king move per second toward its cell for a set time, and the task is to print final positions after all appearances.	Hard8	MathSimulation+1	No attempts yet	2s	1024 MB	Judgeable
Making a Good Binary StringGiven a binary string, find the fewest character flips so that the shortest intervals covering all 0s and all 1s have equal length.	Hard8	Prefix sumDynamic programming+1	No attempts yet	2s	1024 MB	Judgeable
Cat ExercisePlace obstacles on a tree of towers to maximize the total number of moves a cat makes while jumping to the highest reachable tower each time.	Hard8	TreeDynamic programming+1	No attempts yet	2s	1024 MB	Judgeable
Modern MachineGiven N light tiles and M buttons, answer Q queries that ask how many tiles are red after pressing buttons L to R in order.	Hard8	SimulationSegment tree+1	No attempts yet	2.5s	1024 MB	Judgeable
Tractor PathsGiven N intervals with sorted endpoints, answer queries for the shortest path length between two tractors and count special tractors on some shortest path.	Hard8	GraphShortest path+1	No attempts yet	4s	1024 MB	Judgeable
Subtree ActivationGiven a rooted tree, find the fewest toggles so that every subtree is exactly the active set at some moment, starting and ending with all ornaments off.	Hard8	TreeDynamic programming+1	No attempts yet	2s	1024 MB	Judgeable
Branch ManagerGiven a rooted tree of one-way roads and a line of destinations, find how many people can reach their target after closing roads before each one enters.	Hard8	TreeGreedy+1	No attempts yet	4s	1024 MB	Judgeable
Digits of UnityCount n-element sets of distinct integers from 1 to m whose bitwise AND has at least k set bits, modulo 998244353.	Hard8	Bit manipulationCombinatorics+1	No attempts yet	5s	1024 MB	Judgeable
Italian Data CentersGiven a connected graph with colored vertices, find the diameter of the graph after k rounds of the doubling construction.	Hard8	Shortest pathGraph+1	No attempts yet	2s	1024 MB	Judgeable
Base Station PruningFor each interval of base numbers s to e, find the minimum total length of tree passages that keep those bases mutually reachable, using any bases in between.	Hard8	TreeDivide and conquer+1	No attempts yet	4s	1024 MB	Judgeable
Meeting Room 2Count the ways to cancel all but one meeting, one per day, so that the total room cost over the removal days is minimal, modulo 1,000,000,007.	Hard8	Dynamic programmingIntervals	No attempts yet	2s	1024 MB	Judgeable
StudentsGiven M intervals of students each group excludes, find the day a complaint is filed under common-knowledge reasoning and the students who file it, or -1 if none.	Hard8	IntervalsSorting+1	No attempts yet	1s	1024 MB	Judgeable
Team FormationFor each query, find the largest (A1[i]+A2[j]) times (B1[i]+B2[j]) over a range of boys i and a range of girls j.	Hard8	GeometrySegment tree+2	No attempts yet	6s	1024 MB	Judgeable
Hilbert's Hedge MazeGiven a hedge maze of order n built from a Hilbert-curve-like string, find the shortest walking distance between two cells.	Hard8	RecursionDivide and conquer+2	No attempts yet	1s	1024 MB	Judgeable
Forming a TeamGiven N points (A_i, B_i) and Q pairs, find for each pair the smallest extra cost a third point adds to their bounding box in both coordinates.	Hard8	Segment treeSorting+1	No attempts yet	3s	1024 MB	Judgeable
Convex HullFor each point, count how many of the other points lie on the convex hull after that point is removed from the set.	Hard8	GeometrySorting+1	No attempts yet	1s	1024 MB	Judgeable
Qizz Quzz (Hard)Given a sequence of labels, find the longest prefix that some set of divisor-to-string rules in a Generalized Fizz Buzz program could produce.	Hard8	StringString matching+1	No attempts yet	1s	1024 MB	Judgeable
Flipping and cutting (Hard)Given circumference c and squared step s, find which pairs make repeated wedge flips return the paper to all black, and the fewest rounds needed.	Hard8	Number theoryMath+1	No attempts yet	1s	1024 MB	Judgeable
Russian Roulette (Hard)Given n players, c chambers, and k passes per empty shot, find the starting seat with the best survival chance and its probability modulo 1000000009.	Hard8	Dynamic programmingProbability+1	No attempts yet	5s	1024 MB	Judgeable
Ferries (Hard)Given car positions a_1 to a_k seen during a trip on 2n cars, find the fewest ferry crossings and an L/R string of ferry types that produces them.	Hard8	MathBit manipulation	No attempts yet	10s	1024 MB	Judgeable
Ultimate magic rectangles (Hard)Count the ways to fill a 3-row, c-column grid with nonnegative integers so every triplet on a line across all three rows sums to s, modulo 10^9 + 9.	Hard8	MathCombinatorics+1	No attempts yet	1s	1024 MB	Judgeable
Dijkstra's Nightmare (Hard)Construct graphs with negative edges where the reference Dijkstra variant terminates after processing exactly p vertices, for given p up to 10^7.	Hard8	Shortest pathGraph+1	No attempts yet	60s	1024 MB	Judgeable
CopierGiven a sequence built by repeatedly copying a contiguous block and inserting the copy to its right, recover the original permutation of 1 to l.	Hard8	String matchingGreedy+1	No attempts yet	1s	1024 MB	Judgeable
Maximum enjoymentGiven an undirected graph with link capacities, find the maximum total bandwidth from s to t when each path may use at most L links and shared links cannot exceed capacity.	Hard8	GraphShortest path+1	No attempts yet	10s	1024 MB	Judgeable
Exploring the caveGiven n and d, build a cave with n chambers and labeled one-way tunnels that meets the parameters, or report that no such cave exists.	Hard8	GraphCombinatorics+1	No attempts yet	10s	1024 MB	Judgeable
Grid travelGiven an r by c grid and two distinct points, output a longest simple path between them as a string of U, D, L, R moves.	Hard8	GraphDivide and conquer+1	No attempts yet	1s	1024 MB	Judgeable
Harvesting potatoesGiven an r by c field and a per-pass limit d, schedule row and column passes so each cell is harvested once, using the fewest passes and then the lowest difficulty.	Hard8	ImplementationGreedy+1	No attempts yet	1s	1024 MB	Judgeable
Rotate to divideGiven base b and ratio k, find the smallest number whose last digit moved to the front gives exactly 1/k of the original, and output its length and first digit.	Hard8	Number theoryMath	No attempts yet	1s	1024 MB	Judgeable
Klingon High Council TrainingTwo players take turns moving up to K of N ships toward the origin, each move strictly closer, and the task is to find the winner under optimal play.	Hard8	Game theoryNumber theory+1	No attempts yet	1s	1024 MB	Judgeable
Counting CasesGiven N rabbits that each pick a value from the set X, count the assignments whose product equals k for every k from 1 to K, modulo 1e9+7.	Hard8	Number theoryDynamic programming+2	No attempts yet	1s	1024 MB	Judgeable
Forest ScientistGiven N and a list of positions, find the values at those positions in the insertion order that minimizes the weighted energy of the resulting BST.	Hard8	TreeGreedy+2	No attempts yet	1s	1024 MB	Judgeable
Oil Pipeline IIEach plant needs T units of fuel from point events inside its station range [L, R]. After each point event, print the plants that just started running.	Hard8	Segment treeImplementation+1	No attempts yet	4s	1024 MB	Judgeable
Operator PartyStarting from X = 0, apply the operations for multiples of A to F at each step i from 1 to N, in the given priority order, and print the final X.	Hard8	MathBit manipulation+1	No attempts yet	2s	512 MB	Judgeable
Name-Preserving NetworkDesign a connected 4-regular simple graph on 10 to 100 vertices whose only automorphism is the identity, so the vertex labels can be recovered.	Hard8	GraphImplementation	No attempts yet	10s	1024 MB	Judgeable
The Cartesian JobGiven N rotating lasers with random directions, find the probability that some open time interval exists when no laser touches the segment from (0, 0) to (0, 1000).	Hard8	GeometryProbability+1	No attempts yet	40s	1024 MB	Judgeable
Robot Programming StrategyFind a move string that wins a single-elimination bracket against all given opponent programs, whatever the seating order, or report IMPOSSIBLE.	Hard8	StringGreedy+2	No attempts yet	20s	1024 MB	Judgeable
Bacterial TacticsBecca and Terry alternately place H or V colonies on a grid with radioactive cells, and the task is to count Becca's winning first moves or report 0.	Hard8	Game theoryGraph+1	No attempts yet	30s	1024 MB	Judgeable
New Elements: Part 1Given N molecules with Codium and Jamarium atom counts, count the orderings by molecular weight that some pair of positive integer atomic weights can produce.	Hard8	GeometrySorting+1	No attempts yet	20s	1024 MB	Judgeable
Pottery LotteryPlayer 100 gets up to 99 forge or peek actions against 20 vases, then picks one vase for their token so that it ends up as the unique minimum.	Hard8	ProbabilityGame theory+1	No attempts yet	40s	1024 MB	Judgeable
ZillionimGiven a Zillionim position on 10^12 coins where each move removes 10^10 consecutive coins, decide whether you can beat a random-moving AI most of the time.	Hard8	Game theoryMath+1	No attempts yet	50s	1024 MB	Judgeable
Go To Considered HelpfulFind the fewest-line program of N/S/E/W moves and G jumps that moves Marlin from M's cell to N's cell on a grid avoiding #.	Hard8	BFSGraph+1	No attempts yet	Not set	1024 MB	Judgeable
Join the RanksGiven R ranks and S suits, find the fewest pile-swap operations that regroup the deck by rank, and output the pile sizes for each operation.	Hard8	MathImplementation	No attempts yet	Not set	1024 MB	Judgeable