Problems

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Total results29,098 problems

Nearby Gravitation
Medium7
Hash map, Geometry
No attempts yet
Time limit
5s
Memory limit
128 MB
Judgeable
Go Board
Medium7
Graph
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Splitting the Seminar into Two Groups
Medium7
Graph, Brute force
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Pyramid Sequence
Medium7
Number theory, Math
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Treasure Chests
Medium7
Dynamic programming, Bit manipulation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Delta Quadrant
Medium7
Dynamic programming, Tree
No attempts yet
Time limit
5s
Memory limit
128 MB
Judgeable
Holodeck Hacking
Medium7
Backtracking, Math
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Interstellar Trade
Medium7
Binary search, Greedy+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Card Game
Medium7
Game theory, Bit manipulation
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Erasing Game
Medium7
Combinatorics, Sorting+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Beautiful Odd Array
Medium7
Math, Combinatorics
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
NP-hard
Medium7
Dynamic programming, Intervals
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Line Game
Medium7
Game theory, Graph
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Anagrams divisible by 11
Medium7
Dynamic programming, Combinatorics+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Go up the Ultras
Medium7
Stack, Segment tree
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Hide and seek
Medium7
Geometry, Sorting
No attempts yet
Time limit
5s
Memory limit
128 MB
Judgeable
Join two kingdoms
Medium7
Tree, Sorting+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Handsome GCD
Medium7
Number theory
No attempts yet
Time limit
5s
Memory limit
128 MB
Judgeable
Subway
Medium7
Shortest path, Graph+2
No attempts yet
Time limit
8s
Memory limit
128 MB
Judgeable
Escape
Medium7
Graph, Greedy+1
No attempts yet
Time limit
8s
Memory limit
128 MB
Judgeable
Catch the Bomb
Medium7
Graph, Topological sort+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Swapping Game
Medium7
Greedy, Graph
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Lock Pattern
Medium7
Dynamic programming, Bit manipulation
No attempts yet
Time limit
5s
Memory limit
128 MB
Judgeable
Math Homework
Medium7
Matrix, Number theory+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Dice on a Board
Medium7
Shortest path, Graph
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Shortest Fence
Medium7
Geometry, Sorting
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Tornado operation homework
Medium7
BFS, Graph+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Line of Sight
Medium7
Geometry, Sorting+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
No Change
Medium7
Dynamic programming, Bit manipulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Pogo-Cow
Medium7
Dynamic programming, Sorting
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Torrent
Medium7
Graph, Binary search+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Bonus Cards
Medium7
Probability, Dynamic programming+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Easy Geometry
Medium7
Geometry, Two pointers
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Hack Protection
Medium7
Bit manipulation, Prefix sum+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
It Can Be Arranged
Medium7
Graph, Intervals+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Decoding the Hallway
Medium7
String, Recursion+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Factorials with an even number of trailing zeroes
Medium7
Number theory, Dynamic programming+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
VivoParc Animal Assignment
Medium7
Backtracking, Graph
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Clock Hands
Medium7
Math, Geometry
No attempts yet
Time limit
5s
Memory limit
128 MB
Judgeable
Directional Resemblance
Medium7
Geometry, Sorting+1
No attempts yet
Time limit
10s
Memory limit
128 MB
Judgeable
Don't Burst the Balloon
Medium7
Geometry, Binary search
No attempts yet
Time limit
7s
Memory limit
128 MB
Judgeable
Odd Area Lattice Squares
Medium7
Combinatorics, Math+1
No attempts yet
Time limit
5s
Memory limit
256 MB
Judgeable
Seven Segment Graph
Medium7
Graph, Math+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Airport Sort
Medium7
Binary search, Greedy+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Box
Medium7
Dynamic programming, Combinatorics
No attempts yet
Time limit
5s
Memory limit
128 MB
Judgeable
Shortest Subsequence With Sum at Least X
Medium7
Prefix sum, Queue
No attempts yet
Time limit
3s
Memory limit
256 MB
Judgeable
Distance Between Two Integers
Medium7
Dynamic programming, Combinatorics+1
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
Cup of Cowards
Medium7
Dynamic programming, Sorting
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
The Stones Game
Medium7
Game theory, Math
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Super Ants
Medium7
Dynamic programming, Prefix sum+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Battle for Silver
Medium7
Graph, Brute force
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Card Trick
Medium7
Dynamic programming, Probability+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Young diagrams and Young tableaux
Medium7
Dynamic programming, Combinatorics+1
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
Infix to Prefix
Medium7
Dynamic programming, Intervals+1
No attempts yet
Time limit
5s
Memory limit
128 MB
Judgeable
Jingle Balls
Medium7
Dynamic programming, Tree
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Endless Candy Party
Medium7
Math, Hash map+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
The course Mirko wins
Medium7
Shortest path, Graph+1
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
Traitor
Medium7
Dynamic programming, Tree
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Intelligent Traffic Surveillance
Medium7
Simulation, Binary search+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Hooking Up Power to the LEDs
Medium7
Shortest path, Union-find+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Suitcases
Medium7
Probability, Math
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Bytehattan
Medium7
Union-find, Graph
No attempts yet
Time limit
10s
Memory limit
128 MB
Judgeable
Demonstrations
Medium7
Intervals, Sorting
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
Speed Cameras
Medium7
Greedy, Tree+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Marbles
Medium7
Number theory, Math+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
The Hero
Medium7
Shortest path, Intervals
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Genetic engineering
Medium7
Dynamic programming, Greedy+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Janosik
Medium7
Math, Bit manipulation
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Blankets
Medium7
Segment tree, Sorting+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Sum of all numbers made from even digits
Medium7
Dynamic programming, Combinatorics+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Huge Knight
Medium7
Math, BFS
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
XOR Set Expansion
Medium7
Bit manipulation, BFS+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Sequence Merging
Medium7
Divide and conquer, Stack+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Division Game
Medium7
Game theory, Number theory+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Plastic Bags
Medium7
Backtracking, Brute force
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Self-Replicating Numbers
Medium7
Number theory, Math+1
No attempts yet
Time limit
2s
Memory limit
64 MB
Judgeable
Necklace of Beads
Medium7
Combinatorics, Number theory+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Trucking Diesel
Medium7
Shortest path, Graph+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Forensic
Medium7
Graph, DFS
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Weather
Medium7
Graph, String
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Jawbreak
Medium7
Backtracking, Simulation+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
The Urge to Merge
Medium7
Dynamic programming, Bit manipulation
No attempts yet
Time limit
5s
Memory limit
128 MB
Judgeable
Xenospeak
Medium7
Combinatorics, Dynamic programming+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Optimal Milking
Medium7
Segment tree, Dynamic programming
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
The Bessie Shuffle
Medium7
Simulation, Math
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
The Bessie Shuffle
Medium7
Simulation, Math
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Cow Curling
Medium7
Geometry, Sorting+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Ski Course Rating
Medium7
Union-find, Sorting+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Fludtown
Medium7
Geometry, Math
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Width of a Point Set
Medium7
Geometry, Two pointers
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Pair
Medium7
Backtracking, BFS+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Smallest LNR Sequence
Medium7
Graph, Greedy+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Magic Square
Medium7
Backtracking, Brute force+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Possible First Tiles
Medium7
Topological sort, Brute force+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Ride the dominoes on a chessboard
Medium7
Dynamic programming, Bit manipulation
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
Cleaning the Room
Medium7
Union-find, Graph+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
The Four Towers of Hanoi
Medium7
Dynamic programming, Math
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
Clearing an N×M Board
Medium7
Backtracking, BFS+1
No attempts yet
Time limit
3s
Memory limit
256 MB
Judgeable
Dominosa
Medium7
Backtracking, Brute force
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Stamps
Medium7
Shortest path, Number theory
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable

Title	Level	Topics	Solved	Time limit	Memory limit	Judge
Nearby GravitationCount pairs of 3D points whose Euclidean distance is smaller than k for each test case.	Medium7	Hash mapGeometry	No attempts yet	5s	128 MB	Judgeable
Go BoardPlace black stones on empty cells to capture lone white stones and leave as many empty cells as possible.	Medium7	Graph	No attempts yet	1s	128 MB	Judgeable
Splitting the Seminar into Two GroupsPick the largest subset of students that splits into two groups with each grade kept together and no disliking pair in the same group.	Medium7	GraphBrute force	No attempts yet	1s	128 MB	Judgeable
Pyramid SequenceCount the distinct pairs formed at matching positions of two repeating pyramid sequences of heights N and M.	Medium7	Number theoryMath	No attempts yet	1s	128 MB	Judgeable
Treasure ChestsOpen up to 12 treasure chests in the order that leaves the most keys, spending colored keys before wild ones to fill each lock.	Medium7	Dynamic programmingBit manipulation+1	No attempts yet	1s	128 MB	Judgeable
Delta QuadrantStarting anywhere on a weighted tree, find the shortest closed tour that visits all but k planets and returns to the start.	Medium7	Dynamic programmingTree	No attempts yet	5s	128 MB	Judgeable
Holodeck HackingCount the positive integers X whose sum with their digit reversal equals the given Y.	Medium7	BacktrackingMath	No attempts yet	2s	128 MB	Judgeable
Interstellar TradePlace the two ends of a wormhole on a line of planets to minimize the largest trip distance, where each trip uses the wormhole shortcut or the direct distance.	Medium7	Binary searchGreedy+2	No attempts yet	2s	128 MB	Judgeable
Card GameTwo players alternately pick cards and OR the value into a shared number, losing by completing 511 or moving with no cards left.	Medium7	Game theoryBit manipulation	No attempts yet	1s	128 MB	Judgeable
Erasing GameCount the ordered sequences A whose entries can each be matched to a distinct entry of S that is at least as large.	Medium7	CombinatoricsSorting+2	No attempts yet	1s	128 MB	Judgeable
Beautiful Odd ArrayFill empty grid cells with digits 1 to 9 so every run of H vertical and W horizontal cells sums to an odd number, and count the completions modulo 1e9+7.	Medium7	MathCombinatorics	No attempts yet	1s	128 MB	Judgeable
NP-hardFind the shortest route that visits each of up to 1500 cities once when every city keeps all lower-numbered cities on one side of it.	Medium7	Dynamic programmingIntervals	No attempts yet	2s	256 MB	Judgeable
Line GameTwo players alternately draw unused axis-parallel lines through marked points on the previous line, and the program names the side with a winning strategy.	Medium7	Game theoryGraph	No attempts yet	1s	128 MB	Judgeable
Anagrams divisible by 11Count distinct digit permutations of N with no leading zero that are multiples of 11, modulo 1e9+7.	Medium7	Dynamic programmingCombinatorics+1	No attempts yet	1s	128 MB	Judgeable
Go up the UltrasThe program reads an altitude profile of up to 100000 points and prints the indices of every peak with prominence of at least 150000 centimeters.	Medium7	StackSegment tree	No attempts yet	1s	128 MB	Judgeable
Hide and seekCount, for each of up to 10 seekers, how many of 10,000 kids are visible when 10,000 disjoint wall segments block sight lines.	Medium7	GeometrySorting	No attempts yet	5s	128 MB	Judgeable
Join two kingdomsTwo trees with up to 40000 nodes each are joined by one uniformly random cross edge, and you must output the expected diameter of the combined tree.	Medium7	TreeSorting+2	No attempts yet	1s	128 MB	Judgeable
Handsome GCDFind the maximum of gcd times length over all contiguous subarrays of the given sequence.	Medium7	Number theory	No attempts yet	5s	128 MB	Judgeable
SubwayFind a subway route that uses the fewest line boardings and, among those, takes the most minutes.	Medium7	Shortest pathGraph+2	No attempts yet	8s	128 MB	Judgeable
EscapeDecide whether detours on a tree can collect one-time HP gains so the hero walks from chamber 1 to chamber t without HP dropping below zero.	Medium7	GraphGreedy+1	No attempts yet	8s	128 MB	Judgeable
Catch the BombGiven forbidden left and upper neighbor pairs over 26 letters, find the largest fillable square grid, capped at 20.	Medium7	GraphTopological sort+1	No attempts yet	2s	128 MB	Judgeable
Swapping GameRearrange the letters of the given string into the lexicographically smallest string that fits the per-position allowed letters, or report NO SOLUTION.	Medium7	GreedyGraph	No attempts yet	1s	128 MB	Judgeable
Lock PatternCount valid lock patterns on a 3 by 4 grid whose Manhattan segment lengths sum to L while avoiding the dots in S.	Medium7	Dynamic programmingBit manipulation	No attempts yet	5s	128 MB	Judgeable
Math HomeworkCount N-digit strings, leading zeros allowed, whose divisibility by each of 1 to 6 matches a given pattern, modulo 1e9+7.	Medium7	MatrixNumber theory+1	No attempts yet	1s	128 MB	Judgeable
Dice on a BoardRoll a die from the start cell to the target for face-matching bonuses, reporting Impossible when unreachable and Infinity when the score grows without bound.	Medium7	Shortest pathGraph	No attempts yet	1s	128 MB	Judgeable
Shortest FenceEnclose up to 100 disjoint circles with the shortest closed fence and print its length rounded to five decimals.	Medium7	GeometrySorting	No attempts yet	1s	128 MB	Judgeable
Tornado operation homeworkChoose the fewest nondecreasing addition and exponent steps so the iterated value plus C is a multiple of 10 to the P.	Medium7	BFSGraph+1	No attempts yet	1s	128 MB	Judgeable
Line of SightCount the pairs of N points outside a central circle whose connecting segment avoids the circle.	Medium7	GeometrySorting+1	No attempts yet	1s	128 MB	Judgeable
No ChangePay the ordered purchases with distinct coins, each covering one consecutive group within its value, to maximize unused value, or print -1.	Medium7	Dynamic programmingBit manipulation+2	No attempts yet	1s	128 MB	Judgeable
Pogo-CowStarting from any target and hopping in one direction with non-decreasing jump lengths, collect the maximum total points from visited targets.	Medium7	Dynamic programmingSorting	No attempts yet	1s	128 MB	Judgeable
TorrentHwiwon collects all n pieces from seeds with fixed online windows at one piece per second and reports the earliest time the file is complete, or -1.	Medium7	GraphBinary search+1	No attempts yet	2s	128 MB	Judgeable
Bonus CardsDmitry compares his chance of winning a seat when he enters with a double-slot card and with a single-slot card.	Medium7	ProbabilityDynamic programming+1	No attempts yet	1s	128 MB	Judgeable
Easy GeometryFind the largest area of an axis-aligned rectangle that fits inside a given convex polygon.	Medium7	GeometryTwo pointers	No attempts yet	1s	128 MB	Judgeable
Hack ProtectionCount the subarrays of the given array whose bitwise XOR equals their bitwise AND.	Medium7	Bit manipulationPrefix sum+2	No attempts yet	1s	128 MB	Judgeable
It Can Be ArrangedFind the fewest rooms for daily courses that each need several parallel rooms, where a room can run course j after course i only if cleaning ends first.	Medium7	GraphIntervals+1	No attempts yet	2s	128 MB	Judgeable
Decoding the HallwayFor each query, decide whether the given string appears as a contiguous substring of the turn record built after n hallway walks.	Medium7	StringRecursion+2	No attempts yet	1s	128 MB	Judgeable
Factorials with an even number of trailing zeroesCount how many k from 0 to n have a factorial ending in an even number of zeros for each query.	Medium7	Number theoryDynamic programming+1	No attempts yet	1s	128 MB	Judgeable
VivoParc Animal AssignmentAssign one of four species to each of up to 100 enclosures so visible pairs differ, and print the lexicographically smallest valid assignment.	Medium7	BacktrackingGraph	No attempts yet	1s	128 MB	Judgeable
Clock HandsThe program finds the earliest time at or after the given time when the second hand bisects the angle between the other two hands with no overlap.	Medium7	MathGeometry	No attempts yet	5s	128 MB	Judgeable
Directional ResemblanceFind the pair with the smallest nonzero angle among up to 120000 3D vectors per dataset, where some vectors come from a given pseudorandom generator.	Medium7	GeometrySorting+1	No attempts yet	10s	128 MB	Judgeable
Don't Burst the BalloonFind the largest radius of a sphere resting on the floor of a square box with vertical needles that avoids the walls and needles.	Medium7	GeometryBinary search	No attempts yet	7s	128 MB	Judgeable
Odd Area Lattice SquaresYou count every lattice square with odd area that fits inside each m by n grid.	Medium7	CombinatoricsMath+1	No attempts yet	5s	256 MB	Judgeable
Seven Segment GraphGiven a graph, list every digit and subdivision degree whose seven-segment display graph has the same shape.	Medium7	GraphMath+1	No attempts yet	1s	128 MB	Judgeable
Airport SortFor each lineup of zone-grouped tickets, subtract the smallest possible longest simultaneous walk from the minimum adjacent swaps that group the zones.	Medium7	Binary searchGreedy+1	No attempts yet	2s	128 MB	Judgeable
BoxCount left-packed orderings of boxes with total width at most W so no unpacked box still fits the leftover space.	Medium7	Dynamic programmingCombinatorics	No attempts yet	5s	128 MB	Judgeable
Shortest Subsequence With Sum at Least XFind the length of the shortest contiguous subarray whose sum is at least X, or report -1 when none exists.	Medium7	Prefix sumQueue	No attempts yet	3s	256 MB	Judgeable
Distance Between Two IntegersSum the digitwise absolute differences over every ordered pair of integers from A to B, modulo 1,000,000,007.	Medium7	Dynamic programmingCombinatorics+1	No attempts yet	3s	128 MB	Judgeable
Cup of CowardsChoose hits from five bounded characters to reach at least L damage at minimum cost, breaking ties by smaller damage.	Medium7	Dynamic programmingSorting	No attempts yet	3s	128 MB	Judgeable
The Stones GameGiven N stones and M players in cyclic order with forced removals, decide if player X has a strategy that always takes the last stone.	Medium7	Game theoryMath	No attempts yet	1s	128 MB	Judgeable
Super AntsAn ant on a grid cell collects its value and spawns clones along eight rays within the remaining time, and you compute the total score modulo 1e9+7.	Medium7	Dynamic programmingPrefix sum+1	No attempts yet	1s	128 MB	Judgeable
Battle for SilverGiven coin counts on the vertices of a connected planar graph, find the largest total coins of a pairwise adjacent set.	Medium7	GraphBrute force	No attempts yet	1s	128 MB	Judgeable
Card TrickGiven the cards on the observed hopping path, compute the chance that a random start among positions 1 to 10 ends on the same final card.	Medium7	Dynamic programmingProbability+1	No attempts yet	2s	128 MB	Judgeable
Young diagrams and Young tableauxCount the fillings of the given Young diagram with numbers 1 to N that rise weakly across rows and strictly down columns.	Medium7	Dynamic programmingCombinatorics+1	No attempts yet	3s	128 MB	Judgeable
Infix to PrefixGiven a prefix expression with spaces and parentheses removed, compute the smallest and largest values over all valid parses.	Medium7	Dynamic programmingIntervals+1	No attempts yet	5s	128 MB	Judgeable
Jingle BallsMove as few balls as possible so the two sides of every split differ by at most one ball, or report impossible.	Medium7	Dynamic programmingTree	No attempts yet	1s	128 MB	Judgeable
Endless Candy PartyFor each s from 1 to N, find the smallest day k on which exactly s tables share the same floor(b_i/k) candies per person.	Medium7	MathHash map+1	No attempts yet	2s	128 MB	Judgeable
The course Mirko winsFind the directed cycle where Mirko beats Slavko with the fewest roads, breaking ties by the largest time difference.	Medium7	Shortest pathGraph+1	No attempts yet	3s	128 MB	Judgeable
TraitorCover as many marked nodes of a forest as possible by assigning each a distinct neighboring watcher with no two marked nodes watching each other.	Medium7	Dynamic programmingTree	No attempts yet	1s	128 MB	Judgeable
Intelligent Traffic SurveillanceReplay service logs to recover zone and exemption states and print one penalty ticket per vehicle-day with every violating photo.	Medium7	SimulationBinary search+2	No attempts yet	1s	128 MB	Judgeable
Hooking Up Power to the LEDsAssign a voltage to each junction so every wire joins equal voltages and each LED drops between m and M, with the smallest possible highest voltage.	Medium7	Shortest pathUnion-find+1	No attempts yet	1s	128 MB	Judgeable
SuitcasesGiven n passengers, k belt suitcases with none yours, and misplacement chance p, compute the chance your suitcase missed the plane.	Medium7	ProbabilityMath	No attempts yet	1s	128 MB	Judgeable
BytehattanAfter each street closure in an n by n grid, decide whether the two endpoints of the closed street stay connected by open streets.	Medium7	Union-findGraph	No attempts yet	10s	128 MB	Judgeable
DemonstrationsChoose up to two intervals to cancel so the total covered length of the remaining intervals shrinks as much as possible.	Medium7	IntervalsSorting	No attempts yet	3s	128 MB	Judgeable
Speed CamerasPlace the most cameras on the intersections of a tree so no simple route passes more than k cameras.	Medium7	GreedyTree+1	No attempts yet	1s	128 MB	Judgeable
MarblesDecide whether the given multiset of digits can be split into two equal halves with equal digit products.	Medium7	Number theoryMath+1	No attempts yet	1s	128 MB	Judgeable
The HeroFind the shortest sailing time from island 1 to island n, waiting on islands to dodge trap intervals that forbid presence on active days.	Medium7	Shortest pathIntervals	No attempts yet	1s	128 MB	Judgeable
Genetic engineeringDelete the fewest elements so the rest splits into blocks of k equal values, and print the lexicographically smallest among the longest such genomes.	Medium7	Dynamic programmingGreedy+1	No attempts yet	1s	128 MB	Judgeable
JanosikCount how many money bags Janosik pockets when n caskets holding 1 to n bags are emptied by the smallest-first split, pocket, or hand-out rule.	Medium7	MathBit manipulation	No attempts yet	1s	128 MB	Judgeable
BlanketsCompute the average pairwise overlap area of n identical axis-aligned rectangles from their corner positions.	Medium7	Segment treeSorting+2	No attempts yet	1s	128 MB	Judgeable
Sum of all numbers made from even digitsAdd up every distinct number that can be formed from the available copies of digits 2, 4, 6 and 8, modulo 1,000,000,007.	Medium7	Dynamic programmingCombinatorics+1	No attempts yet	1s	128 MB	Judgeable
Huge KnightGiven two squares on an N by N board with N up to 10^15, find the minimum number of knight moves between them.	Medium7	MathBFS	No attempts yet	1s	128 MB	Judgeable
XOR Set ExpansionGiven an initial integer set, count the expansion rounds that add XORs of current and original elements until the set stops growing.	Medium7	Bit manipulationBFS+1	No attempts yet	1s	128 MB	Judgeable
Sequence MergingRepeatedly replace an adjacent pair with its larger value and pay that value, ordering the merges to leave the smallest total cost.	Medium7	Divide and conquerStack+1	No attempts yet	1s	128 MB	Judgeable
Division GameDecide whether the first player wins a game that divides chosen entries of one matrix row per move.	Medium7	Game theoryNumber theory+1	No attempts yet	1s	128 MB	Judgeable
Plastic BagsPack every item weighing up to 2000 grams into capacity limited bags, including one free bag set by total price, at the lowest extra cost.	Medium7	BacktrackingBrute force	No attempts yet	1s	128 MB	Judgeable
Self-Replicating NumbersFind every n-digit base-b number whose square ends with the same n digits.	Medium7	Number theoryMath+1	No attempts yet	2s	64 MB	Judgeable
Necklace of BeadsCount distinct circular necklaces of n beads in three colors up to rotation and reflection for each n until -1.	Medium7	CombinatoricsNumber theory+1	No attempts yet	1s	128 MB	Judgeable
Trucking DieselStarting with 25000 liters that doubles as fuel, move east, south, or west across an altitude grid to the opposite corner with the most diesel left.	Medium7	Shortest pathGraph+2	No attempts yet	1s	128 MB	Judgeable
ForensicChange at most one array entry so the pointer chain starting at index 0 visits as many distinct indices as possible before reaching -1.	Medium7	GraphDFS	No attempts yet	2s	512 MB	Judgeable
WeatherReconstruct the first and last days of a weather string from its multiset of length-d substrings, choosing the alphabetically smallest pair when several fit.	Medium7	GraphString	No attempts yet	2s	512 MB	Judgeable
JawbreakRemove groups of at least 3 same-coloured connected balls to maximize the sum of squared group sizes plus a 1000 point clearing bonus.	Medium7	BacktrackingSimulation+1	No attempts yet	2s	512 MB	Judgeable
The Urge to MergeYou pick disjoint adjacent pairs in a 3 by n grid to maximize the sum of the products of paired values.	Medium7	Dynamic programmingBit manipulation	No attempts yet	5s	128 MB	Judgeable
XenospeakGiven words per page and a page number, print the first and last words on that page over tilings of a, ab and bb ordered by length then alphabetically.	Medium7	CombinatoricsDynamic programming+1	No attempts yet	1s	128 MB	Judgeable
Optimal MilkingEach day one machine value changes, then choose nonadjacent machines with maximum total output and add it to the overall sum.	Medium7	Segment treeDynamic programming	No attempts yet	1s	128 MB	Judgeable
The Bessie ShuffleShuffle the top M cards with the given permutation, move the top card to a pile, repeat until empty, and report the card at each queried pile position.	Medium7	SimulationMath	No attempts yet	1s	128 MB	Judgeable
The Bessie ShuffleRepeatedly shuffle the top M cards by a fixed permutation, deal the top card onto a pile, and report the labels at queried pile positions.	Medium7	SimulationMath	No attempts yet	1s	128 MB	Judgeable
Cow CurlingCount the stones of each team that lie inside or on some triangle formed by three opposing stones.	Medium7	GeometrySorting+1	No attempts yet	1s	128 MB	Judgeable
Ski Course RatingFrom each marked start cell, find the smallest elevation-step limit that connects it to at least T cells.	Medium7	Union-findSorting+1	No attempts yet	1s	128 MB	Judgeable
FludtownCount the corners of the region inside the square town where the Fenster house is closest.	Medium7	GeometryMath	No attempts yet	2s	512 MB	Judgeable
Width of a Point SetGiven up to 100000 points, compute the integer part of the squared minimum width of a strip enclosing all points.	Medium7	GeometryTwo pointers	No attempts yet	2s	512 MB	Judgeable
PairPair up equal digits on a board of at most 5 by 5 through empty squares to remove the most pairs with the smallest total path length.	Medium7	BacktrackingBFS+1	No attempts yet	2s	512 MB	Judgeable
Smallest LNR SequenceGiven n and a binary string s, find the position of s in the lexicographically smallest de Bruijn sequence of order n.	Medium7	GraphGreedy+1	No attempts yet	1s	128 MB	Judgeable
Magic SquareFill the empty cells with the unused numbers from 1 to N squared so every row, column, and both diagonals share one sum.	Medium7	BacktrackingBrute force+1	No attempts yet	2s	1024 MB	Judgeable
Possible First TilesGiven a top view of 5x5 letter tiles on a grid, print NO when the view is impossible and otherwise list the tiles that could have been laid first.	Medium7	Topological sortBrute force+1	No attempts yet	1s	128 MB	Judgeable
Ride the dominoes on a chessboardPlace exactly K non-overlapping dominoes on an N by 3 board of integers to maximize the sum of covered cells.	Medium7	Dynamic programmingBit manipulation	No attempts yet	3s	128 MB	Judgeable
Cleaning the RoomEach of N bottles fits exactly two of L drawers, and each bottle in order claims a drawer through a chain of displaced bottles or is discarded.	Medium7	Union-findGraph+1	No attempts yet	1s	256 MB	Judgeable
The Four Towers of HanoiMove all N disks to the last peg with four pegs in the fewest moves and print the count per test case.	Medium7	Dynamic programmingMath	No attempts yet	3s	128 MB	Judgeable
Clearing an N×M BoardRoll a ball that slides until blocked on a board with obstacles and find the fewest slides that visit every empty square.	Medium7	BacktrackingBFS+1	No attempts yet	3s	256 MB	Judgeable
DominosaReconstruct the domino tiling of an n by n+1 grid where each unordered symbol pair appears exactly once.	Medium7	BacktrackingBrute force	No attempts yet	1s	128 MB	Judgeable
StampsFor each set of stamp denominations, decide if every large postage is payable without the 1-lar stamp and give the largest postage that still needs it.	Medium7	Shortest pathNumber theory	No attempts yet	1s	128 MB	Judgeable