Problems

Pick a problem, code in the editor, and watch the judge run real test cases. The archive is open to browse

Under construction

Still being built. Things may change

Total results29,463 problems

Indomie
Medium4
Probability, Combinatorics+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Hotel
Medium4
Implementation, Brute force+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Minimum Swaps
Medium4
Sorting, Greedy+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Sultan's Land
Medium4
Array, Hash map+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Sales Report
Medium4
Sorting, Hash map+2
No attempts yet
Time limit
4s
Memory limit
128 MB
Judgeable
Advanced ASCII Cubes
Medium4
Implementation, Simulation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Longest Ordered Subsequence
Medium4
Dynamic programming, Array+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Two Circles
Medium4
Geometry, Math+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Hansel and Grethel
Medium4
Geometry, Math+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Cross Spider
Medium4
Geometry, Math+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
What Day Is It?
Medium4
Implementation, Math+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Cannons
Medium4
Segment tree, Array
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Balance
Medium4
Brute force, Backtracking+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Holiday Costing
Medium4
Brute force, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Handong the Salesman!
Medium4
Graph, Tree+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Density Map
Medium4
Prefix sum, Matrix+1
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
Neighbouring Towns
Medium4
Array, Brute force
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Canoes
Medium4
Greedy, Two pointers+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Triangles
Medium4
Sorting, Greedy
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Polygon
Medium4
Graph, DFS+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Pilots
Medium4
Sliding window, Two pointers+1
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
Rectangles 2
Medium4
Math, Number theory+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Improvisation
Medium4
Simulation, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
ROT13
Medium4
Hash map, String+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Handshakes
Medium4
Dynamic programming, Combinatorics+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Byteland Lottery
Medium4
Math, Number theory+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Dyzio
Medium4
Tree, DFS+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Grid Shading Puzzle
Medium4
Greedy, Sorting
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Garden
Medium4
Hash map, Geometry+1
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
Odd-Length Cycle
Medium4
Graph, BFS+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Hyperclock
Medium4
Math, Combinatorics
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Megavirus
Medium4
Tree, Bit manipulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Cipher
Medium4
Math, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Restaurants
Medium4
Shortest path, Graph+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Singing
Medium4
Greedy
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Coins
Medium4
Sorting, Combinatorics+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Snake
Medium4
Simulation, Queue+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Train
Medium4
Greedy, Hash map
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Chochlik
Medium4
Union-find, Graph+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Run Bajtocja
Medium4
Number theory, Math
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Calendars
Medium4
Prefix sum, Binary search
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Bajtozja the Frog
Medium4
Graph, BFS+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Soldiers
Medium4
Combinatorics, Math+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Summing Jaś
Medium4
String, Math+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Banquet
Medium4
Graph, DFS
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Drawers
Medium4
Greedy, Array
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Ladder
Medium4
Dynamic programming, Math
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Matches
Medium4
Dynamic programming, Array
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Banks
Medium4
Number theory, Math
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Gathering Mushrooms
Medium4
Prefix sum, Array
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Flipping the Vegetable Garden
Medium4
Prefix sum, Matrix
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Dollars and Euros
Medium4
Sorting, Simulation
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
The Birthday Party
Medium4
Number theory, Array
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Merchant
Medium4
Tree, Dynamic programming+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Recursive Pattern (Szlaczek)
Medium4
Recursion, Array+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Independent Architecture
Medium4
BFS, Matrix
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Indiana Jones Among the Zombies
Medium4
BFS, Shortest path+1
No attempts yet
Time limit
6s
Memory limit
128 MB
Judgeable
Snow Plows
Medium4
Graph, DFS
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
Digging a Well
Medium4
Geometry, Two pointers
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
A Kitten on the Fence
Medium4
Number theory
No attempts yet
Time limit
5s
Memory limit
128 MB
Judgeable
Exam Preparation
Medium4
Greedy, Sorting
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Zbyszek
Medium4
Graph, Math+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Experiment
Medium4
Topological sort, Graph+1
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
Banker
Medium4
Stack, Simulation
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Politicians
Medium4
Brute force, Bit manipulation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Circle Dance
Medium4
Graph, DFS
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Crazy Arduino
Medium4
Simulation, Implementation
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Match Maker
Medium4
Simulation, Greedy
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
DSLR
Medium4
BFS, Graph
No attempts yet
Time limit
6s
Memory limit
256 MB
Judgeable
Three Pin Bowling
Medium4
Simulation, Implementation
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Dome Stadium
Medium4
Prefix sum
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Escape the Maze with a Drill
Medium4
Shortest path, BFS+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Rubik's Cube
Medium4
Brute force, Simulation
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Maximum Detour
Medium4
Geometry, Brute force+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Missile Protector
Medium4
Dynamic programming, Binary search
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Internet Cafe Fee
Medium4
Brute force, Math+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Guess the Word
Medium4
String, Sorting
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Coins
Medium4
Dynamic programming, Combinatorics
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Quad Trees
Medium4
Divide and conquer, Recursion+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
The Frobenius Problem
Medium4
Dynamic programming, Number theory
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Oulipo
Medium4
String matching, String
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Lucky Light
Medium4
Geometry, Intervals+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Gnome
Medium4
Simulation, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Actors
Medium4
Graph, DFS
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Police in a Line
Medium4
Geometry, Brute force
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Starship Hakodate-maru
Medium4
Brute force, Sorting+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
e-Market
Medium4
Simulation, Implementation
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
One...Two...Five!
Medium4
Brute force, Simulation
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
And Now For Something Completely Different!
Medium4
Prefix sum, Simulation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Single Digit Adder
Medium4
Stack, Recursion
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Job Scheduling by Open Bidding
Medium4
Dynamic programming
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Mixing Words
Medium4
Dynamic programming, String
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Rate of Return
Medium4
Binary search, Math
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
A Card Trick
Medium4
Brute force, Combinatorics+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
The Same Game
Medium4
Simulation, BFS+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Hotel Reservations
Medium4
Intervals, Sorting+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Walking While Drinking Beer
Medium4
BFS, Graph
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Peg Solitaire
Medium4
Backtracking, Brute force+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Timing
Medium4
Matrix, Simulation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
A Voting Protocol
Medium4
Simulation, Sorting
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable

Title	Level	Topics	Solved	Time limit	Memory limit	Judge
IndomieEach of the N people ahead takes a uniformly random remaining item among rice, sugar, and Indomie (Indomie limited to S). Find the probability Indomie remains for Felix, as a percentage.	Medium4	ProbabilityCombinatorics+2	No attempts yet	1s	128 MB	Judgeable
HotelFor each team, pick the cheapest hotel in its bed-size category that can hold the team, breaking ties by larger bed size and then input order.	Medium4	ImplementationBrute force+2	No attempts yet	1s	128 MB	Judgeable
Minimum SwapsFor each string of distinct lowercase letters, find the minimum number of arbitrary swaps needed to sort it into alphabetical order.	Medium4	SortingGreedy+2	No attempts yet	1s	128 MB	Judgeable
Sultan's LandGiven P pillars on an N by N grid, count how many sets of four pillars form the corners of an axis-aligned rectangle.	Medium4	ArrayHash map+2	No attempts yet	1s	128 MB	Judgeable
Sales ReportGiven N sale records of item, salespoint, and quantity, print a table of totals with items as columns and salespoints as rows.	Medium4	SortingHash map+2	No attempts yet	4s	128 MB	Judgeable
Advanced ASCII CubesRender stacked cubes on an N by M grid as ASCII art using isometric projection, minimizing output lines and width.	Medium4	ImplementationSimulation+1	No attempts yet	1s	128 MB	Judgeable
Longest Ordered SubsequenceGiven a sequence of N integers, find the length of the longest non-decreasing subsequence.	Medium4	Dynamic programmingArray+2	No attempts yet	1s	128 MB	Judgeable
Two CirclesCompute the area of the overlapping region of two circles from their centers and radii, printing the result to three decimals.	Medium4	GeometryMath+1	No attempts yet	1s	128 MB	Judgeable
Hansel and GrethelGiven two landmarks on a map and the compass bearing from the walkers to each landmark, find the walkers' coordinates.	Medium4	GeometryMath+1	No attempts yet	1s	128 MB	Judgeable
Cross SpiderDecide whether all given points in 3D space lie on a single plane.	Medium4	GeometryMath+1	No attempts yet	1s	128 MB	Judgeable
What Day Is It?Given an Earth date from 2000 to 3000, print the weekday on Earth and on each of up to 8 planets with their own prime-based leap-year calendars.	Medium4	ImplementationMath+1	No attempts yet	1s	128 MB	Judgeable
CannonsFor each query, report the minimum and maximum value in the given subarray of cannon strengths.	Medium4	Segment treeArray	No attempts yet	1s	128 MB	Judgeable
BalanceCount the orders and pan choices for placing n distinct weights so the left pan is never heavier than the right at any step.	Medium4	Brute forceBacktracking+2	No attempts yet	2s	128 MB	Judgeable
Holiday CostingFor each stay length at a hotel, choose one stay/pay deal, repeated as allowed, to minimize the nights you pay for.	Medium4	Brute forceImplementation+2	No attempts yet	1s	128 MB	Judgeable
Handong the Salesman!Given a tree, start at node 1 and visit m listed nodes in order, summing the tree distances between consecutive stops.	Medium4	GraphTree+2	No attempts yet	1s	128 MB	Judgeable
Density MapFor each cell of an n by n binary grid, sum the entries within Chebyshev distance r, using a 2D sliding-window or prefix-sum over the square neighborhood.	Medium4	Prefix sumMatrix+1	No attempts yet	3s	128 MB	Judgeable
Neighbouring TownsGiven a symmetric shortest-distance table for n towns, list every pair A,B such that no third town C satisfies dist(A,B) = dist(A,C) + dist(C,B).	Medium4	ArrayBrute force	No attempts yet	1s	128 MB	Judgeable
CanoesGiven a canoe weight limit and each participant's weight, find the minimum number of two-person canoes needed to carry everyone.	Medium4	GreedyTwo pointers+2	No attempts yet	1s	128 MB	Judgeable
TrianglesGiven a list of segment lengths, find the largest perimeter of a non-degenerate triangle formed by three of them, or print NIE if none exists.	Medium4	SortingGreedy	No attempts yet	1s	128 MB	Judgeable
PolygonGiven a convex polygon and a set of non-crossing diagonals, report the largest number of sides among the pieces the diagonals divide it into.	Medium4	GraphDFS+2	No attempts yet	1s	128 MB	Judgeable
PilotsFind the length of the longest contiguous fragment whose maximum minus minimum is at most t.	Medium4	Sliding windowTwo pointers+1	No attempts yet	3s	128 MB	Judgeable
Rectangles 2Count the number of unordered pairs (a, b) of positive integers with a <= b and a*b <= n.	Medium4	MathNumber theory+1	No attempts yet	2s	512 MB	Judgeable
ImprovisationGiven a chord progression and a melody with pauses, remap each played note to the nearest note in the current chord's scale, advancing the chord every fourth position.	Medium4	SimulationImplementation+2	No attempts yet	1s	128 MB	Judgeable
ROT13Given a list of lowercase words, count ordered pairs (w1, w2) from the list where w2 equals the ROT13 encoding of w1.	Medium4	Hash mapString+2	No attempts yet	1s	128 MB	Judgeable
HandshakesCount the matchings of a path with n vertices, then print the last digit of that count.	Medium4	Dynamic programmingCombinatorics+1	No attempts yet	1s	256 MB	Judgeable
Byteland LotteryGiven up to 10^6 ball labels, compute the digital root of the sum of products over all non-empty subsets.	Medium4	MathNumber theory+2	No attempts yet	1s	128 MB	Judgeable
DyzioParse a 0/1 description of recursive halving cuts and output the cut count at which the first shortest piece appears.	Medium4	TreeDFS+2	No attempts yet	1s	128 MB	Judgeable
Grid Shading PuzzleGiven per-row and per-column shaded counts for an n by n board, decide whether a valid 0/1 board exists.	Medium4	GreedySorting	No attempts yet	1s	128 MB	Judgeable
GardenCount the number of axis-aligned squares whose four corners are all points from a given set.	Medium4	Hash mapGeometry+1	No attempts yet	3s	128 MB	Judgeable
Odd-Length CycleFor each of t undirected graphs, decide whether it contains an odd-length cycle (equivalently, is not bipartite).	Medium4	GraphBFS+1	No attempts yet	1s	128 MB	Judgeable
HyperclockGiven the cycle sizes of N clocks, the tour visits every configuration once; its length is the number of configurations, the product of the sizes.	Medium4	MathCombinatorics	No attempts yet	1s	128 MB	Judgeable
MegavirusGiven k and n viruses from generation k in a binary tree, find the deepest generation whose node is an ancestor of all given viruses.	Medium4	TreeBit manipulation+2	No attempts yet	1s	128 MB	Judgeable
CipherGiven n and m, print the units digits of fib(n) through fib(m) concatenated with no separators.	Medium4	MathImplementation+2	No attempts yet	1s	128 MB	Judgeable
RestaurantsEvery city connects by weighted roads and some hold restaurants; report the largest distance from any city to its closest restaurant.	Medium4	Shortest pathGraph+1	No attempts yet	1s	128 MB	Judgeable
SingingThe task is to place the fewest books so every student in a row has one or sits next to one.	Medium4	Greedy	No attempts yet	1s	512 MB	Judgeable
CoinsCount the ways to place coins of sizes 1 to n into slots with capacities a_i so every coin fits, modulo 1000000007.	Medium4	SortingCombinatorics+1	No attempts yet	1s	512 MB	Judgeable
SnakeSimulate the snake's moves on the board and report the move on which its head hits a wall or its own body.	Medium4	SimulationQueue+1	No attempts yet	1s	512 MB	Judgeable
TrainCount the fewest round trips a train needs to drop its wagons from the back at their assigned cities in order.	Medium4	GreedyHash map	No attempts yet	1s	512 MB	Judgeable
ChochlikDecide for each department whether wheels linked by same-direction and opposite-direction belts can all spin without contradiction.	Medium4	Union-findGraph+1	No attempts yet	1s	512 MB	Judgeable
Run BajtocjaGiven each runner's lap time in seconds, compute how many 1 km laps each runner completes before all runners meet at the start again.	Medium4	Number theoryMath	No attempts yet	1s	512 MB	Judgeable
CalendarsConvert each given date to its day of year with one calendar, then locate the matching month and day in the other calendar.	Medium4	Prefix sumBinary search	No attempts yet	1s	512 MB	Judgeable
Bajtozja the FrogThe frog hops between stones at most s apart starting from stone p and then dives length s to finish as far from the start as possible.	Medium4	GraphBFS+1	No attempts yet	1s	512 MB	Judgeable
SoldiersCount the monotonic lineups of n distinguishable soldiers by height and output the last four digits of the count.	Medium4	CombinatoricsMath+1	No attempts yet	1s	512 MB	Judgeable
Summing JaśAdd up to 100 signed decimal numbers with up to 100 digits on each side of the comma and print the shortest form of the sum.	Medium4	StringMath+1	No attempts yet	1s	512 MB	Judgeable
BanquetFind how many round tables are needed by counting the cycles in the left-neighbor links.	Medium4	GraphDFS	No attempts yet	1s	512 MB	Judgeable
DrawersPush as few drawers in as possible so the pull-out lengths strictly increase from the top drawer down.	Medium4	GreedyArray	No attempts yet	1s	128 MB	Judgeable
LadderCount the ways to climb s rungs with steps of one or two and report each answer modulo 2^p for up to a million queries.	Medium4	Dynamic programmingMath	No attempts yet	1s	128 MB	Judgeable
MatchesStarting from one match, fire spreads to each neighbor no taller than the burning match, and the task asks for the largest group that can burn.	Medium4	Dynamic programmingArray	No attempts yet	1s	128 MB	Judgeable
BanksFor each of up to a million denomination pairs, print the largest amount no combination can pay, or -1 when infinitely many such amounts exist.	Medium4	Number theoryMath	No attempts yet	1s	128 MB	Judgeable
Gathering MushroomsChoose the earliest day t of at least 1 that maximizes the total weight of mushrooms still edible, where each weight grows daily.	Medium4	Prefix sumArray	No attempts yet	1s	128 MB	Judgeable
Flipping the Vegetable GardenApply up to one million rectangle flips to an n by n binary garden and print the final layout.	Medium4	Prefix sumMatrix	No attempts yet	1s	128 MB	Judgeable
Dollars and EurosSelect n of 2n-1 wallets with the fixed dollar-sorted rule so dollars and euros each reach half the totals.	Medium4	SortingSimulation	No attempts yet	1s	128 MB	Judgeable
The Birthday PartyFind the smallest guest count m so that every candy pile leaves at least one leftover when divided equally among m guests.	Medium4	Number theoryArray	No attempts yet	1s	128 MB	Judgeable
MerchantFind the simple path, possibly empty, in a weighted tree whose edge weights sum to the largest value.	Medium4	TreeDynamic programming+1	No attempts yet	1s	128 MB	Judgeable
Recursive Pattern (Szlaczek)Given a starting sequence that is repeatedly extended by appending its own reversal, report the value at position M.	Medium4	RecursionArray+1	No attempts yet	1s	128 MB	Judgeable
Independent ArchitectureCount the wall cells plus the empty cells enclosed by the single closed wall loop in each grid.	Medium4	BFSMatrix	No attempts yet	1s	128 MB	Judgeable
Indiana Jones Among the ZombiesEvery turn each zombie steps toward chamber 1 along a shortest path, and you find the first turn with more than K arrivals or confirm Indiana survives.	Medium4	BFSShortest path+1	No attempts yet	6s	128 MB	Judgeable
Snow PlowsFind the fewest trails that cover every street exactly once by counting odd-degree intersections in each connected part.	Medium4	GraphDFS	No attempts yet	3s	128 MB	Judgeable
Digging a WellFind the smallest vertical gap between the ground polyline and the aquifer polyline over their shared x range.	Medium4	GeometryTwo pointers	No attempts yet	1s	128 MB	Judgeable
A Kitten on the FenceList every hop size K from 1 to N that visits all N pickets on a circular fence before repeating.	Medium4	Number theory	No attempts yet	5s	128 MB	Judgeable
Exam PreparationSchedule preparation days before each exam day and find how many days before the earliest exam study must start.	Medium4	GreedySorting	No attempts yet	1s	128 MB	Judgeable
ZbyszekCheck whether remembered degrees can form a forest by testing that their sum is even and at most twice the dot count minus two.	Medium4	GraphMath+1	No attempts yet	2s	128 MB	Judgeable
ExperimentOrient each undecided corridor so the whole maze stays acyclic, following the smallest-numbered topological order of the fixed corridors.	Medium4	Topological sortGraph+1	No attempts yet	3s	128 MB	Judgeable
BankerSimulate deposits stacked as envelopes and withdrawals taken from the top of the pile, then report the final till and remaining pile totals.	Medium4	StackSimulation	No attempts yet	1s	128 MB	Judgeable
PoliticiansSplit up to 18 people with rivalry pairs into two groups with no rival trio in either group and maximize the first group.	Medium4	Brute forceBit manipulation+1	No attempts yet	1s	128 MB	Judgeable
Circle DanceFind the largest want-link cycle in which each girl is disliked by fewer than half of the members.	Medium4	GraphDFS	No attempts yet	1s	128 MB	Judgeable
Crazy ArduinoSimulate Jongsu's moves and the chasing robots on the R by C board, and report the final board or the move where he is caught.	Medium4	SimulationImplementation	No attempts yet	1s	128 MB	Judgeable
Match MakerPair N men with N women from full preference lists to output the man-optimal stable matching with no blocking pair.	Medium4	SimulationGreedy	No attempts yet	1s	128 MB	Judgeable
DSLRFind the shortest DSLR command string that turns register value A into target B, breaking ties in alphabetical order.	Medium4	BFSGraph	No attempts yet	6s	256 MB	Judgeable
Three Pin BowlingAdd up ten frames of three-pin bowling from the throw list, applying strike and spare bonuses and rejecting invalid games.	Medium4	SimulationImplementation	No attempts yet	1s	128 MB	Judgeable
Dome StadiumChoose the village coordinate that minimizes the total fan-weighted travel distance.	Medium4	Prefix sum	No attempts yet	1s	256 MB	Judgeable
Escape the Maze with a DrillDecide whether a robot can reach the target on a grid by drilling through at most k walls.	Medium4	Shortest pathBFS+2	No attempts yet	1s	128 MB	Judgeable
Rubik's CubeDecide whether two 54-sticker cube descriptions show the same coloring under some rotation of the cube.	Medium4	Brute forceSimulation	No attempts yet	1s	128 MB	Judgeable
Maximum DetourGiven the vertices of a polygonal path in order, compute the largest ratio of along-path length to straight-line distance over all vertex pairs.	Medium4	GeometryBrute force+1	No attempts yet	1s	128 MB	Judgeable
Missile ProtectorSelect the most missiles that form a non-decreasing height sequence in arrival order.	Medium4	Dynamic programmingBinary search	No attempts yet	1s	128 MB	Judgeable
Internet Cafe FeeYou start playing at a given time for a given duration and pay the cheapest mix of hourly charges and nightly flat passes.	Medium4	Brute forceMath+1	No attempts yet	1s	128 MB	Judgeable
Guess the WordGiven each uppercase word, output the next distinct arrangement of its letters in dictionary order, or the word itself when it is already last.	Medium4	StringSorting	No attempts yet	1s	128 MB	Judgeable
CoinsCount the unordered combinations of up to 20 coin values that sum to the target amount M.	Medium4	Dynamic programmingCombinatorics	No attempts yet	1s	128 MB	Judgeable
Quad TreesBuild the quadtree partition of each binary image and print its level-order bitstream as uppercase hex without leading zeros.	Medium4	Divide and conquerRecursion+2	No attempts yet	1s	128 MB	Judgeable
The Frobenius ProblemCount the integers up to 1,000,000 that are not nonnegative combinations of four given numbers and report the largest such integer.	Medium4	Dynamic programmingNumber theory	No attempts yet	1s	128 MB	Judgeable
OulipoCount overlapping occurrences of a pattern W in a text T over uppercase letters for each test case.	Medium4	String matchingString	No attempts yet	1s	128 MB	Judgeable
Lucky LightCount the lighted regions on the x-axis that lie outside the shadows a point light casts from the given segments.	Medium4	GeometryIntervals+1	No attempts yet	1s	128 MB	Judgeable
GnomeSimulate Same-Gnome moves on a letter board, clearing connected groups with gravity and scoring each removal.	Medium4	SimulationImplementation+2	No attempts yet	1s	128 MB	Judgeable
ActorsDecide whether every role can be filled by a distinct available actor who rehearsed it.	Medium4	GraphDFS	No attempts yet	1s	128 MB	Judgeable
Police in a LineDecide whether any three of up to 300 given points are collinear, repeating for each dataset in the input.	Medium4	GeometryBrute force	No attempts yet	1s	128 MB	Judgeable
Starship Hakodate-maruGiven a limit up to 151200, find the largest amount that splits into a cube plus a tetrahedral number.	Medium4	Brute forceSorting+2	No attempts yet	1s	128 MB	Judgeable
e-MarketDealers send buy and sell orders that match on price with best-price priority, and the program reports deal prices per commodity and payments per dealer.	Medium4	SimulationImplementation	No attempts yet	1s	128 MB	Judgeable
One...Two...Five!Try every +,-,*,/ insertion evaluated left to right, skipping division by zero, and report the most frequent result containing the digit 3.	Medium4	Brute forceSimulation	No attempts yet	1s	256 MB	Judgeable
And Now For Something Completely Different!The program scans a chore record for split points where both halves favor the opposite child from the total and prints each match with rounded percentages.	Medium4	Prefix sumSimulation+1	No attempts yet	1s	128 MB	Judgeable
Single Digit AdderEvaluate each line as an arithmetic expression of single digits with plus, minus, and parentheses.	Medium4	StackRecursion	No attempts yet	1s	128 MB	Judgeable
Job Scheduling by Open BiddingPick bids whose total seconds fit the available time so the total payment is as large as possible.	Medium4	Dynamic programming	No attempts yet	1s	128 MB	Judgeable
Mixing WordsDecide whether the third word interleaves the first two words while keeping each word's letter order.	Medium4	Dynamic programmingString	No attempts yet	1s	256 MB	Judgeable
Rate of ReturnFind the monthly rate that makes the compounded deposits equal the reported fund value.	Medium4	Binary searchMath	No attempts yet	1s	128 MB	Judgeable
A Card TrickGiven five cards, pick the hidden card and the order of the other four to satisfy the decoding rule, choosing the lexicographically smallest arrangement.	Medium4	Brute forceCombinatorics+1	No attempts yet	1s	128 MB	Judgeable
The Same GameSimulate the greedy Same Game strategy that repeatedly removes the largest same-color cluster and applies gravity and column shifts.	Medium4	SimulationBFS+1	No attempts yet	1s	128 MB	Judgeable
Hotel ReservationsFind the fewest rooms that fit all reservations when a room freed at checkout needs C more minutes of cleaning.	Medium4	IntervalsSorting+2	No attempts yet	2s	128 MB	Judgeable
Walking While Drinking BeerDecide whether the festival is reachable when each 20-bottle box allows 1000 meters of Manhattan travel between refills at stores.	Medium4	BFSGraph	No attempts yet	1s	128 MB	Judgeable
Peg SolitaireMove pegs by jumping over adjacent pegs into empty holes to leave as few pegs as possible with the fewest moves.	Medium4	BacktrackingBrute force+1	No attempts yet	1s	128 MB	Judgeable
TimingApply the directed fractional troop moves for t hours, then add each fortress value to its linked neighbors and report the minimum.	Medium4	MatrixSimulation+1	No attempts yet	1s	128 MB	Judgeable
A Voting ProtocolSimulate ranked-ballot rounds where each voter backs the top unpicked candidate and the top vote getters fill k seats with alphabetical tie breaks.	Medium4	SimulationSorting	No attempts yet	1s	128 MB	Judgeable