Problems

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Total results29,450 problems

Resignation
Medium5
Dynamic programming, Brute force+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Laboratory
Medium5
Brute force, BFS+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Financial Tsunami
Medium5
Simulation, Graph+1
No attempts yet
Time limit
10s
Memory limit
512 MB
Judgeable
Connectivity Potential
Medium5
Graph, Shortest path+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Mario Party
Medium5
Dynamic programming
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
The Other Way
Medium5
Graph, Shortest path+1
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Line Friends (Small)
Medium5
Graph, BFS+2
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Image Quilting (Small)
Medium5
Dynamic programming, Implementation
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
AI Tetris (Small)
Medium5
Simulation, Implementation+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Flower Path
Medium5
Brute force, Backtracking+2
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Love That Only Fails for Me
Medium5
Graph, Minimum spanning tree+2
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Scallion Chicken
Medium5
Binary search, Greedy+2
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Archers of the Geumgang Range
Medium5
Stack, Array+2
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Red Ginseng Game (Easy)
Medium5
BFS, Graph+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Reincarnated as a Slime Researcher (Easy)
Medium5
Greedy, Number theory+2
No attempts yet
Time limit
0.5s
Memory limit
512 MB
Judgeable
Rainwater
Medium5
Array, Two pointers+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Circular Highway
Medium5
Prefix sum, Greedy+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Voter Depression
Medium5
Dynamic programming, Intervals+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Oversized Pancake Flipper (Large)
Medium5
Greedy, Sliding window
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Tidy Numbers (Small)
Medium5
Greedy, Math+1
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Tidy Numbers (Large)
Medium5
Greedy, Math+2
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Unicorn Stable Arrangement
Medium5
Greedy, Implementation+2
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Pony Express (Small)
Medium5
Dynamic programming, Shortest path+1
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Core Training (All Cores)
Medium5
Greedy, Math+2
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Beaming With Joy (Large)
Medium5
Simulation, Graph+2
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Rectangles and Queries
Medium5
Prefix sum, Matrix+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Hamming distance queries
Medium5
Prefix sum, String+2
No attempts yet
Time limit
6s
Memory limit
512 MB
Judgeable
Tiling a 2 by N wall
Medium5
Dynamic programming, Combinatorics
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
From Seoul to Gyeongsan
Medium5
Dynamic programming, Brute force+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Two water jugs
Medium5
Math, Number theory+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Ramps
Medium5
Implementation, Simulation+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Slurpy
Medium5
Recursion, String+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Project Scheduling
Medium5
Topological sort, Dynamic programming+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Shoemaker's Job Order
Medium5
Greedy, Sorting
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Mixing two solutions
Medium5
Two pointers, Sorting+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Building a ranch
Medium5
Dynamic programming, Matrix+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Stone Skipping (SUJEBI)
Medium5
Math, Brute force+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Unchanging numbers
Medium5
Number theory, Math+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Curiosity
Medium5
Number theory, Prefix sum+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Flea Market
Medium5
Greedy, Prefix sum+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Escaping the Barracks
Medium5
Binary search, BFS+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Connect3
Medium5
Backtracking, Simulation+1
No attempts yet
Time limit
0.5s
Memory limit
512 MB
Judgeable
Rock Paper Scissors Machine
Medium5
String, String matching+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Passwords
Medium5
String matching, Hash map+1
No attempts yet
Time limit
1s
Memory limit
64 MB
Judgeable
Amsterdam Distance
Medium5
Geometry, Graph+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
King of the Waves
Medium5
BFS, Graph+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Best Relay Team
Medium5
Greedy, Sorting+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Alien Sunset
Medium5
Math, Number theory+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Deranging Hat
Medium5
Simulation, Sorting+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Education
Medium5
Greedy, Sorting+2
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Despojados
Medium5
Number theory, Combinatorics+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Musical Scale
Medium5
Implementation, Brute force+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Enigma
Medium5
Dynamic programming, Math+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Dinoscan
Medium5
Implementation, Brute force+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Foosball Dynasty
Medium5
Simulation, Implementation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Delayed Work
Medium5
Math, Brute force+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Purple Rain
Medium5
Array, Greedy+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Front Nine
Medium5
Probability, Dynamic programming+2
No attempts yet
Time limit
6s
Memory limit
512 MB
Judgeable
Greedy Generosity
Medium5
Simulation, Greedy+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Candy Sales
Medium5
Array, Prefix sum+1
No attempts yet
Time limit
6s
Memory limit
512 MB
Judgeable
Exciting Startup
Medium5
Binary search, Math+2
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Killer Sudoku
Medium5
Implementation, Simulation+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
nnnnn
Medium5
Math, Binary search+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
3D Printed Statues
Medium5
Greedy, Math+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Tiling
Medium5
Dynamic programming, Combinatorics+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Debug
Medium5
Array, Math+2
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Seat Assignment Algorithm
Medium5
Simulation, Implementation+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Easy Quest
Medium5
Greedy, Implementation+2
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Sweet, sour, bitter, salty
Medium5
Tree, Dynamic programming+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Robot Energy Source Order
Medium5
Sorting, Greedy+2
No attempts yet
Time limit
0.2s
Memory limit
128 MB
Judgeable
Cakey McCakeFace
Medium5
Hash map, Array+2
No attempts yet
Time limit
7s
Memory limit
512 MB
Judgeable
Candy Chain
Medium5
Dynamic programming, Intervals+2
No attempts yet
Time limit
7s
Memory limit
512 MB
Judgeable
Birthday Cake
Medium5
Geometry, Bit manipulation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Imperfect GPS
Medium5
Geometry, Simulation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Sugoroku
Medium5
Dynamic programming, BFS+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Trunk Roads
Medium5
Brute force, Prefix sum+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Hangul LCS
Medium5
Dynamic programming, String+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Counting a^i b^j c^k subsequences
Medium5
Dynamic programming, String+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Consultations before resignation
Medium5
Dynamic programming, Array+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Probability that the knight stays on the board
Medium5
Dynamic programming, Probability+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Pascal's triangle
Medium5
Array, Dynamic programming+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Equal digit sums in an arithmetic sequence
Medium5
Simulation, Implementation+1
No attempts yet
Time limit
2s
Memory limit
64 MB
Judgeable
Xayahh-Rakann at Moloco (Hard)
Medium5
Graph, Union-find+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Calling Extraterrestrial Intelligence Again
Medium5
Number theory, Math+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
The Stove
Medium5
Greedy, Sorting+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Art Exhibition
Medium5
Sorting, Prefix sum+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Maximum range sum? 1
Medium5
Array, Brute force+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Cute Ryan
Medium5
Two pointers, Sliding window+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Signal 1
Medium5
Dynamic programming, Sorting+2
No attempts yet
Time limit
1.5s
Memory limit
128 MB
Judgeable
Largest average
Medium5
Greedy, Math+2
No attempts yet
Time limit
1s
Memory limit
64 MB
Judgeable
Dunglish
Medium5
Implementation, Math+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Glyph Recognition
Medium5
Geometry, Binary search+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
High Score
Medium5
Greedy, Math+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
The Lawyer
Medium5
Sorting, Greedy+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Africa
Medium5
Implementation, Greedy
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Roasting Emma is a barista too
Medium5
Tree, DFS+2
No attempts yet
Time limit
1.5s
Memory limit
128 MB
Judgeable
Gears (2)
Medium5
Simulation, Implementation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
CCTV Blind Spots
Medium5
Brute force, Backtracking+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Sum of a geometric sequence
Medium5
Divide and conquer, Math+1
No attempts yet
Time limit
0.5s
Memory limit
128 MB
Judgeable
Cowburger set discount
Medium5
Greedy, Sorting+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable

Title	Level	Topics	Solved	Time limit	Memory limit	Judge
ResignationGiven each day's consultation length and payment, pick a non-overlapping set of jobs that all finish before day N+1 to maximize total payment.	Medium5	Dynamic programmingBrute force+1	No attempts yet	2s	512 MB	Judgeable
LaboratoryPlace exactly 3 walls on empty cells of a small grid to maximize the number of cells the virus cannot reach.	Medium5	Brute forceBFS+2	No attempts yet	2s	512 MB	Judgeable
Financial TsunamiGiven banks with balances and loans to each other, repeatedly mark as unsafe any bank whose total assets (balance plus loans from safe banks) fall below a limit, and list them in the order they fail.	Medium5	SimulationGraph+1	No attempts yet	10s	512 MB	Judgeable
Connectivity PotentialGiven a directed graph as an adjacency matrix, compute the number of hops in the longest shortest path times the number of ordered pairs attaining it.	Medium5	GraphShortest path+2	No attempts yet	2s	512 MB	Judgeable
Mario PartyGiven a row of coin values and a die roll range, find the maximum total coins collected on any route that reaches past the star within T turns.	Medium5	Dynamic programming	No attempts yet	2s	512 MB	Judgeable
The Other WayCount the number of distinct shortest paths between two towns in a weighted undirected multigraph, modulo 10^9+9.	Medium5	GraphShortest path+1	No attempts yet	2s	256 MB	Judgeable
Line Friends (Small)Given N line segments, build a graph where segments are adjacent when they overlap, then answer shortest-path queries between pairs of segments.	Medium5	GraphBFS+2	No attempts yet	2s	256 MB	Judgeable
Image Quilting (Small)Given two H by W grayscale images, choose one pixel per row forming a connected seam (rows shift by at most one column) minimizing the sum of squared pixel differences, and output that minimum.	Medium5	Dynamic programmingImplementation	No attempts yet	1s	512 MB	Judgeable
AI Tetris (Small)Given a 20x10 Tetris board, find the maximum number of rows a single dropped piece can clear, assuming it falls straight down.	Medium5	SimulationImplementation+2	No attempts yet	1s	512 MB	Judgeable
Flower PathPlace three plus-shaped flowers of 5 cells each on an N x N grid so no two overlap, all stay inside, and the total rented-cell cost is minimal.	Medium5	Brute forceBacktracking+2	No attempts yet	2s	256 MB	Judgeable
Love That Only Fails for MeFind the minimum spanning tree of a graph restricted to edges joining a men-majority school and a women-majority school, or report -1.	Medium5	GraphMinimum spanning tree+2	No attempts yet	2s	256 MB	Judgeable
Scallion ChickenFind the largest integer piece length x such that the scallions yield at least C pieces, then print the total leftover length.	Medium5	Binary searchGreedy+2	No attempts yet	2s	256 MB	Judgeable
Archers of the Geumgang RangeEach archer's dragon moves right and eats peaks lower than its start until it meets a taller peak; find the largest count any archer can eat.	Medium5	StackArray+2	No attempts yet	2s	256 MB	Judgeable
Red Ginseng Game (Easy)Two tokens move around a cycle, each jumping exactly D seats left or right per turn; find the fewest moves until a token lands on the other token's holder.	Medium5	BFSGraph+2	No attempts yet	1s	512 MB	Judgeable
Reincarnated as a Slime Researcher (Easy)Given a starting integer K, repeatedly factor it into two factors at least 2, minimizing the maximum number of splits along any root to leaf path.	Medium5	GreedyNumber theory+2	No attempts yet	0.5s	512 MB	Judgeable
RainwaterGiven stack heights across a 2D world, compute the total rainwater trapped between the blocks after heavy rain.	Medium5	ArrayTwo pointers+2	No attempts yet	1s	256 MB	Judgeable
Circular HighwayCount starting stations on a circular road where buying all fuel and driving forward never empties the tank before returning.	Medium5	Prefix sumGreedy+1	No attempts yet	1s	512 MB	Judgeable
Voter DepressionPick non-overlapping story intervals to multiply exposed voters' propensities and maximize the right-minus-left propensity gap.	Medium5	Dynamic programmingIntervals+1	No attempts yet	2s	512 MB	Judgeable
Oversized Pancake Flipper (Large)Given a row of happy or blank pancakes and a flipper of fixed width K, find the minimum number of flips that makes every pancake happy, or report that it is impossible.	Medium5	GreedySliding window	No attempts yet	5s	512 MB	Judgeable
Tidy Numbers (Small)Given N up to 10^18, find the largest integer at most N whose base-10 digits never decrease from left to right.	Medium5	GreedyMath+1	No attempts yet	5s	512 MB	Judgeable
Tidy Numbers (Large)Given N up to 10^18, find the largest number not exceeding N whose decimal digits are in non-decreasing order.	Medium5	GreedyMath+2	No attempts yet	5s	512 MB	Judgeable
Unicorn Stable ArrangementGiven counts of red, yellow, and blue unicorns, arrange them in a ring so no two neighbors share a hair color, or report IMPOSSIBLE, printing the lexicographically smallest valid string.	Medium5	GreedyImplementation+2	No attempts yet	5s	512 MB	Judgeable
Pony Express (Small)Cities lie on a line with a horse in each; find the minimum time from city 1 to city N, switching horses at intermediate cities, subject to each horse's endurance limit.	Medium5	Dynamic programmingShortest path+1	No attempts yet	5s	512 MB	Judgeable
Core Training (All Cores)With K = N, the AI works only if every core succeeds; split U training units among cores to maximize the product of final success probabilities.	Medium5	GreedyMath+2	No attempts yet	5s	512 MB	Judgeable
Beaming With Joy (Large)Rotate some horizontal/vertical beam shooters by 90 degrees so every empty cell is lit and no shooter is hit by any beam, choosing the lexicographically smallest grid.	Medium5	SimulationGraph+2	No attempts yet	5s	512 MB	Judgeable
Rectangles and QueriesGiven an N by N matrix with values at most 10, answer many rectangle queries, each asking how many distinct integers appear inside the submatrix.	Medium5	Prefix sumMatrix+2	No attempts yet	2s	512 MB	Judgeable
Hamming distance queriesGiven binary strings a and b, answer queries asking for the Hamming distance between a substring of a and a substring of b.	Medium5	Prefix sumString+2	No attempts yet	6s	512 MB	Judgeable
Tiling a 2 by N wallCount the ways to tile a 2 by N wall with 2x1, 1x2, and 1x1 tiles, modulo 1e9+7.	Medium5	Dynamic programmingCombinatorics	No attempts yet	2s	512 MB	Judgeable
From Seoul to GyeongsanChoose walking or cycling for each of N legs so the total time is at most K and the total donation is maximal.	Medium5	Dynamic programmingBrute force+1	No attempts yet	2s	512 MB	Judgeable
Two water jugsGiven two jug capacities a and b, decide whether some sequence of fills, empties, and pours can leave exactly c liters in one jug.	Medium5	MathNumber theory+1	No attempts yet	2s	512 MB	Judgeable
RampsCount rows or columns where every cell has equal height, or where unit ramps of length L can bridge each height step of exactly 1.	Medium5	ImplementationSimulation+1	No attempts yet	2s	512 MB	Judgeable
SlurpyDecide whether each uppercase string is a Slurpy, meaning a Slimp immediately followed by a Slump, where both are defined by recursive grammar rules.	Medium5	RecursionString+2	No attempts yet	2s	512 MB	Judgeable
Project SchedulingGiven each task's duration and its prerequisite tasks, find the minimum total time to finish the whole project.	Medium5	Topological sortDynamic programming+2	No attempts yet	2s	512 MB	Judgeable
Shoemaker's Job OrderOrder N jobs to minimize the total fine paid while each job waits, using the shortest processing time per fine ratio first, with lexicographically smallest ties.	Medium5	GreedySorting	No attempts yet	2s	512 MB	Judgeable
Mixing two solutionsGiven a sorted array of N integers, choose two different elements whose sum is closest to 0, breaking ties toward the smaller (negative) sum.	Medium5	Two pointersSorting+1	No attempts yet	1s	512 MB	Judgeable
Building a ranchGiven an M by N grid with trees and rocks as obstacles, find the side length of the largest square subgrid that contains no obstacle.	Medium5	Dynamic programmingMatrix+2	No attempts yet	1s	512 MB	Judgeable
Stone Skipping (SUJEBI)For each step size d, sum the cells at multiples of d and pick the d with the largest sum, printing 0 0 if that sum is not positive.	Medium5	MathBrute force+2	No attempts yet	2s	512 MB	Judgeable
Unchanging numbersFor a given digit count n, decide whether the n-digit idempotent number ending in 5 or the one ending in 6 is larger.	Medium5	Number theoryMath+1	No attempts yet	2s	512 MB	Judgeable
CuriosityFor each query [a, b], find the primes in the range in order and compute an alternating sum that triples odd-indexed primes.	Medium5	Number theoryPrefix sum+2	No attempts yet	1s	128 MB	Judgeable
Flea MarketEach person has a supply or demand of fleas at unit-distance positions; find the minimum total delivery cost.	Medium5	GreedyPrefix sum+1	No attempts yet	1s	128 MB	Judgeable
Escaping the BarracksFind the minimum level needed to walk from (0,0) to (n-1,m-1) on an n by m grid, using at most one jump that skips over exactly one block in a straight line.	Medium5	Binary searchBFS+2	No attempts yet	1s	256 MB	Judgeable
Connect3Given Black's opening column x and White's winning square (a,b), count final 4x4 board states where White's move there completes three in a row first.	Medium5	BacktrackingSimulation+1	No attempts yet	0.5s	512 MB	Judgeable
Rock Paper Scissors MachineGiven two RPS strings, choose where in the opponent's longer string to start matching your shorter string and report the most wins.	Medium5	StringString matching+2	No attempts yet	1s	512 MB	Judgeable
PasswordsCount ordered pairs of distinct passwords where one string is a substring of the other, treating the passwords as a multiset of short strings.	Medium5	String matchingHash map+1	No attempts yet	1s	64 MB	Judgeable
Amsterdam DistanceIn a half-disc street grid with M radial streets and N circular canals of radius R*y/N, find the shortest path length between two corners using only those streets and canals.	Medium5	GeometryGraph+1	No attempts yet	2s	512 MB	Judgeable
King of the WavesDecide whether Henk (participant 0) can be made tournament king, and if so print the specified BFS-tree order reversed.	Medium5	BFSGraph+1	No attempts yet	2s	512 MB	Judgeable
Best Relay TeamChoose four runners from n, assign one to leg 1 and three to the other legs, minimizing the total time with a lexicographic tie-break.	Medium5	GreedySorting+1	No attempts yet	1s	512 MB	Judgeable
Alien SunsetFind the earliest time when every settlement is dark on its own periodic day, or report that none exists within the term.	Medium5	MathNumber theory+1	No attempts yet	2s	512 MB	Judgeable
Deranging HatGiven a string, find a sorting network that turns its sorted letters back into the original string, following a specified rule.	Medium5	SimulationSorting+2	No attempts yet	2s	512 MB	Judgeable
EducationAssign departments to buildings by a deterministic greedy rule after sorting students descending, matching each to the cheapest available building that fits.	Medium5	GreedySorting+2	No attempts yet	5s	512 MB	Judgeable
DespojadosCount the divisors of N that are squarefree and have at least two prime factors.	Medium5	Number theoryCombinatorics+1	No attempts yet	1s	1024 MB	Judgeable
Musical ScaleGiven a sequence of played keys, decide whether all notes fit one major scale and print the earliest valid tonic, or desafinado.	Medium5	ImplementationBrute force+1	No attempts yet	1s	1024 MB	Judgeable
EnigmaGiven a digit pattern with question marks and an N, find the smallest matching number with no leading zero that is divisible by N.	Medium5	Dynamic programmingMath+2	No attempts yet	1s	1024 MB	Judgeable
DinoscanGiven two binary scans with aligned rows, decide whether shifting the right scan horizontally lets the 1s tile one solid rectangle with no gaps or overlaps.	Medium5	ImplementationBrute force+2	No attempts yet	2s	512 MB	Judgeable
Foosball DynastySimulate a foosball variation where seats rotate after each point and report the team whose scoring streak lasted longest.	Medium5	SimulationImplementation+2	No attempts yet	2s	512 MB	Judgeable
Delayed WorkChoose the integer number of painters that minimizes total cost X times painters plus K/P times P delay charge, then round to three decimals.	Medium5	MathBrute force+2	No attempts yet	1s	512 MB	Judgeable
Purple RainGiven a string of R and B characters, find the contiguous block maximizing \|r - b\|, breaking ties by westernmost start then westernmost end.	Medium5	ArrayGreedy+2	No attempts yet	1s	512 MB	Judgeable
Front NineGiven a clamped random walk on [0,h] with step probabilities, compute the expected area under the piecewise-linear terrain over n steps.	Medium5	ProbabilityDynamic programming+2	No attempts yet	6s	512 MB	Judgeable
Greedy GenerositySimulate a vending machine's coin stock over several purchases, adding a greedy overpayment when exact greedy change is impossible, and report the total excess paid.	Medium5	SimulationGreedy+2	No attempts yet	2s	512 MB	Judgeable
Candy SalesFor each day j, print the minimum over all i at most j of w_i + (j - i).	Medium5	ArrayPrefix sum+1	No attempts yet	6s	512 MB	Judgeable
Exciting StartupFind the smallest number of pieces b so that a string of length t split into b ordered pieces, each carrying a suffix "_a/b", fits in n-character messages.	Medium5	Binary searchMath+2	No attempts yet	3s	512 MB	Judgeable
Killer SudokuRead a 19 by 37 ASCII diagram of a Killer Sudoku grid plus one sum per cage, and report OK or NotOK for all constraints.	Medium5	ImplementationSimulation+2	No attempts yet	1s	512 MB	Judgeable
nnnnnGiven L equal to n times the digit length of n, recover n for L up to a 10^6-digit number.	Medium5	MathBinary search+2	No attempts yet	2s	512 MB	Judgeable
3D Printed StatuesWith one printer that prints a statue or a new printer each day, find the fewest days to produce at least n statues.	Medium5	GreedyMath+2	No attempts yet	2s	512 MB	Judgeable
TilingCount the ways to tile a 3 by W rectangle with 2 by 1 dominoes, printing the result modulo 1e9+7.	Medium5	Dynamic programmingCombinatorics+2	No attempts yet	2s	512 MB	Judgeable
DebugEach call increments every index divisible by the given jump; answer range-sum queries over the resulting array.	Medium5	ArrayMath+2	No attempts yet	3s	512 MB	Judgeable
Seat Assignment AlgorithmAssign n new passengers to seats in a 3-3-3 airplane layout by repeatedly applying an empty-seat and exit-row priority rule, then print the final layout.	Medium5	SimulationImplementation+1	No attempts yet	1s	512 MB	Judgeable
Easy QuestGiven a sequence of gifts (+type), costs (-type), and unicorns (0), decide if every cost can be paid and choose the lexicographically smallest item type for each unicorn.	Medium5	GreedyImplementation+2	No attempts yet	3s	512 MB	Judgeable
Sweet, sour, bitter, saltyCut edges of a rooted binary tree so that at least X resulting components each contain at least K nodes, minimizing total cut cost.	Medium5	TreeDynamic programming+2	No attempts yet	2s	512 MB	Judgeable
Robot Energy Source OrderReorder n energy sources, each with acceleration a_i and duration s_i, to maximize total distance, and print the gain over the given order.	Medium5	SortingGreedy+2	No attempts yet	0.2s	128 MB	Judgeable
Cakey McCakeFaceGiven sorted entry and exit timestamps, find the smallest nonnegative time difference d that maximizes how many entry times t satisfy t + d is an exit time.	Medium5	Hash mapArray+2	No attempts yet	7s	512 MB	Judgeable
Candy ChainGiven a candy string and a list of paid parts (each reversible), find the maximum total value obtainable by repeatedly removing sold parts and rejoining the remainder.	Medium5	Dynamic programmingIntervals+2	No attempts yet	7s	512 MB	Judgeable
Birthday CakeGiven up to 50 candle points and up to 15 cuts, decide whether the cuts carve the cake so that every resulting piece holds exactly one candle.	Medium5	GeometryBit manipulation+2	No attempts yet	2s	512 MB	Judgeable
Imperfect GPSGiven a running path and a recording interval t, compute the percentage of the real distance the GPS receiver loses by sampling positions at fixed times and joining them with straight lines.	Medium5	GeometrySimulation+2	No attempts yet	2s	512 MB	Judgeable
SugorokuSquares 2 to N+1 are each marked 0 or 1; find the smallest die size j such that some sequence of rolls from 1 to j reaches or passes square N+2 without landing on any square marked 1.	Medium5	Dynamic programmingBFS+2	No attempts yet	2s	512 MB	Judgeable
Trunk RoadsChoose one horizontal and one vertical line in an H by W grid to minimize the total distance residents at each cell pay to the nearer chosen line.	Medium5	Brute forcePrefix sum+1	No attempts yet	2s	512 MB	Judgeable
Hangul LCSGiven two Hangul strings of up to 1000 characters each, compute the length of their longest common subsequence in characters.	Medium5	Dynamic programmingString+2	No attempts yet	2s	512 MB	Judgeable
Counting a^i b^j c^k subsequencesCount subsequences of a string of a, b, c that read as some positive number of a's, then b's, then c's, modulo 1e9+7.	Medium5	Dynamic programmingString+1	No attempts yet	2s	512 MB	Judgeable
Consultations before resignationGiven up to 1.5 million days, each with a job of length T_i and pay P_i, pick jobs that fit before day N+1 to maximize total pay.	Medium5	Dynamic programmingArray+2	No attempts yet	2s	512 MB	Judgeable
Probability that the knight stays on the boardA knight on an N by N board makes K random moves, each of the eight directions equally likely; find the probability it is still on the board after K moves.	Medium5	Dynamic programmingProbability+2	No attempts yet	2s	512 MB	Judgeable
Pascal's triangleBuild Pascal's triangle and sum all entries inside the equilateral sub-triangle whose top cell is row R, position C, with side length W.	Medium5	ArrayDynamic programming+2	No attempts yet	1s	512 MB	Judgeable
Equal digit sums in an arithmetic sequenceScan n = 1, 2, 3, ... and stop when some digit sum of Cn + D in base B reaches M occurrences, then print those n values.	Medium5	SimulationImplementation+1	No attempts yet	2s	64 MB	Judgeable
Xayahh-Rakann at Moloco (Hard)Given n jars with m inseparable pairs, decide whether exactly k jars can be placed in one building so that no inseparable pair is split across the two buildings.	Medium5	GraphUnion-find+2	No attempts yet	2s	512 MB	Judgeable
Calling Extraterrestrial Intelligence AgainFor each query with m and fraction a/b, find primes p and q with pq <= m and a/b <= p/q <= 1 that maximize the product pq.	Medium5	Number theoryMath+2	No attempts yet	2s	512 MB	Judgeable
The StoveEach visitor stays for one time unit at a distinct arrival time; with at most K lights, minimize total stove-on time by skipping the largest idle gaps.	Medium5	GreedySorting+1	No attempts yet	1s	256 MB	Judgeable
Art ExhibitionChoose a subset of artworks maximizing the sum of values minus the difference between the largest and smallest sizes in the subset.	Medium5	SortingPrefix sum+1	No attempts yet	1s	256 MB	Judgeable
Maximum range sum? 1Maintain an array under point updates. For each range query, find the maximum of U times a subarray sum plus V times its length over all subarrays inside the range.	Medium5	ArrayBrute force+2	No attempts yet	1s	128 MB	Judgeable
Cute RyanGiven a row of N dolls labeled 1 or 2, find the length of the shortest contiguous block containing at least K dolls labeled 1.	Medium5	Two pointersSliding window+2	No attempts yet	1s	256 MB	Judgeable
Signal 1Choose a subset of points with distinct x-coordinates; maximize the total Euclidean length of the polyline joining them in increasing x order.	Medium5	Dynamic programmingSorting+2	No attempts yet	1.5s	128 MB	Judgeable
Largest averageGiven N grades, repeatedly replace any two numbers with their average until one remains; find the largest possible final value.	Medium5	GreedyMath+2	No attempts yet	1s	64 MB	Judgeable
DunglishGiven a Dutch sentence and per-word dictionary options marked correct or incorrect, output the unique translation and its status, or counts of correct and incorrect translations.	Medium5	ImplementationMath+1	No attempts yet	2s	512 MB	Judgeable
Glyph RecognitionFor each k from 3 to 8, fit the largest origin-centered regular k-gon with a vertex on the +x axis avoiding all points and the smallest one containing all points, then report the k with the best area ratio.	Medium5	GeometryBinary search+2	No attempts yet	2s	512 MB	Judgeable
High ScoreGiven counts of Cog, Tablet, Compass, and Wildcard tokens, assign each Wildcard to one type to maximize a^2+b^2+c^2+7*min(a,b,c).	Medium5	GreedyMath+1	No attempts yet	2s	512 MB	Judgeable
The LawyerFor each day, decide whether two of that day's meetings are disjoint and, if so, output the pair with the smallest earlier-meeting index, then smallest later index.	Medium5	SortingGreedy+2	No attempts yet	2s	512 MB	Judgeable
AfricaGiven N African countries in visit order, find the minimum total visa fee in dollars, counting Namibia's cheaper Cape Town visa when South Africa comes first.	Medium5	ImplementationGreedy	No attempts yet	1s	256 MB	Judgeable
Roasting Emma is a barista tooGiven a weighted tree, compute for every vertex the sum of shortest distances to all other vertices.	Medium5	TreeDFS+2	No attempts yet	1.5s	128 MB	Judgeable
Gears (2)Simulate K turns on a row of 8-tooth gears where a turning gear rotates its neighbor only if the touching teeth have opposite poles, then count gears whose top tooth is S.	Medium5	SimulationImplementation+2	No attempts yet	2s	512 MB	Judgeable
CCTV Blind SpotsPlace each of up to 8 cameras in one of its allowed rotations on an 8x8 grid so that the fewest cells stay unwatched, given walls block sight.	Medium5	Brute forceBacktracking+2	No attempts yet	1s	512 MB	Judgeable
Sum of a geometric sequenceAdd the first n terms of a geometric sequence with first term a and ratio r, then print the sum modulo mod.	Medium5	Divide and conquerMath+1	No attempts yet	0.5s	128 MB	Judgeable
Cowburger set discountGiven prices for burgers, sides, and drinks, report the undiscounted total and the minimum total after forming disjoint triples where each item in a set is sold at 10% off.	Medium5	GreedySorting+2	No attempts yet	1s	128 MB	Judgeable