Problems

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Total results29,423 problems

Cow Hopscotch
Medium6
Dynamic programming, Prefix sum+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Superbull
Medium6
Minimum spanning tree, Graph+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Picky Eater
Medium6
Geometry, Brute force+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Bessie's Birthday Buffet
Medium6
Dynamic programming, Shortest path+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Trapped in the Haybales
Medium6
Two pointers, Sorting+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Cutting Cheese
Medium6
Binary search, Geometry+1
No attempts yet
Time limit
3s
Memory limit
256 MB
Judgeable
Ship Traffic
Medium6
Intervals, Sorting+1
No attempts yet
Time limit
3s
Memory limit
256 MB
Judgeable
Window Manager
Medium6
Simulation, Geometry
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Sky Cities
Medium6
DFS, Graph+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Coin Toss Game
Medium6
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Tree
Medium6
Tree, Brute force+1
No attempts yet
Time limit
3s
Memory limit
256 MB
Judgeable
Interval Composition
Medium6
Prefix sum, Hash map+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Carpets
Medium6
Backtracking, Recursion
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Upside-down prime
Medium6
Number theory, Implementation
No attempts yet
Time limit
3s
Memory limit
256 MB
Judgeable
NAFTA
Medium6
Dynamic programming, Intervals+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Snake
Medium6
Geometry, Simulation
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Speak your mind!
Medium6
Dynamic programming, Math
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Ancient symbol
Medium6
Simulation, Implementation+2
No attempts yet
Time limit
1s
Memory limit
2 MB
Judgeable
King of penalty
Medium6
Greedy, Sorting
No attempts yet
Time limit
1s
Memory limit
16 MB
Judgeable
Potemkin cycle
Medium6
Graph, BFS+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Ice Hockey World Championship
Medium6
Divide and conquer, Sorting+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Calvinball Championship Team Assignment
Medium6
Backtracking, Graph+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Calvinball team division
Medium6
Graph, Backtracking+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Deque Sort 2
Medium6
Dynamic programming, Sorting+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Catching Eggs
Medium6
Prefix sum, Sorting+1
No attempts yet
Time limit
5s
Memory limit
256 MB
Judgeable
Contest Pizza Cutting
Medium6
Geometry, Brute force+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Apples and Bananas
Medium6
Dynamic programming, Prefix sum
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Merging Files
Medium6
Dynamic programming, Intervals+1
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Circuit Counting
Medium6
Divide and conquer, Hash map
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Safe Passage
Medium6
Greedy, Sorting+1
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Undetected Route
Medium6
Union-find, Binary search+2
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Save the computer
Medium6
Dynamic programming, Math
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Free Willy
Medium6
BFS, Graph+1
No attempts yet
Time limit
5s
Memory limit
256 MB
Judgeable
Eight puzzle
Medium6
BFS, Shortest path+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Sleeping at Work
Medium6
Dynamic programming
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Boss Rush
Medium6
Graph, Binary search
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Special Services
Medium6
Graph, Simulation
No attempts yet
Time limit
3s
Memory limit
256 MB
Judgeable
Traveling Cellsperson
Medium6
Math, Graph
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Fired
Medium6
Graph, BFS+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
GG NO RE OMG CHEATZ
Medium6
Dynamic programming, Probability+1
No attempts yet
Time limit
3s
Memory limit
256 MB
Judgeable
Herding Sheep
Medium6
Binary search, Graph
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Paintball
Medium6
Graph, Greedy
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Getting Rid of Coins
Medium6
Greedy, Math+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Restaurant Orders
Medium6
Dynamic programming
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Vacuum Tubes
Medium6
Sorting, Two pointers+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Chicken Joggers
Medium6
Dynamic programming, Tree+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Forest Highway
Medium6
Geometry
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Cow Crane
Medium6
Brute force, Greedy+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Tomosynthesis
Medium6
Geometry, Intervals+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Proteins
Medium6
Dynamic programming, Greedy+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Absurdistan Roads III
Medium6
Graph, Greedy+1
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
A1 Paper
Medium6
Greedy, Math
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Magic Checkerboard
Medium6
Dynamic programming, Math+1
No attempts yet
Time limit
5s
Memory limit
256 MB
Judgeable
Zig Zag Nametag
Medium6
Greedy, String+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Watering the Flower Garden
Medium6
Union-find, Graph
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Uniting the Three Kingdoms
Medium6
BFS, Graph+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Adjoin the Networks
Medium6
Tree, Greedy+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Floppy Music
Medium6
Dynamic programming, Intervals
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Markleft
Medium6
Stack, String+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Above or Below the Koch Curve
Medium6
Recursion, Geometry+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Frogs With Styles
Medium6
Shortest path, Graph+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Depacting
Medium6
Recursion, String+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Landlocked
Medium6
Shortest path, BFS+2
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Smallest Hex Multiple
Medium6
BFS, Graph+2
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Addition Affliction
Medium6
Greedy, Math+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Implication
Medium6
Brute force, Bit manipulation+1
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
4×n Tiling
Medium6
Dynamic programming, Bit manipulation
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Coin Turning Game
Medium6
Game theory, Dynamic programming+2
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Assigning Work with Penalty Points
Medium6
Graph
No attempts yet
Time limit
3s
Memory limit
256 MB
Judgeable
Hole in the Wall
Medium6
Matrix, Brute force
No attempts yet
Time limit
3s
Memory limit
256 MB
Judgeable
Red Rectangles
Medium6
Stack, Dynamic programming+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Binomial coefficient 4
Medium6
Number theory, Combinatorics
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Buying Books 3
Medium6
Graph, Shortest path
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Minimizing the LCM
Medium6
Number theory, Math
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Railway Tickets
Medium6
Intervals, Sorting+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Farthest node in a weighted tree
Medium6
Tree, DFS
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Currency Conversion
Medium6
Dynamic programming, Prefix sum
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Sum of Squares of Fibonacci Numbers
Medium6
Math, Matrix+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Colby's Costly Collectibles
Medium6
Geometry, Math
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Chasing the Cheetahs
Medium6
Binary search, Math
No attempts yet
Time limit
3s
Memory limit
256 MB
Judgeable
Jumping Yoshi
Medium6
Graph, BFS+1
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Lunch Menu
Medium6
Sorting, Two pointers+1
No attempts yet
Time limit
3s
Memory limit
256 MB
Judgeable
Plankton Food
Medium6
Shortest path, Graph
No attempts yet
Time limit
5s
Memory limit
256 MB
Judgeable
Concatenation
Medium6
String matching, Combinatorics
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Drink Responsibly
Medium6
Dynamic programming, Math
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Equilibrium State
Medium6
Math, Matrix
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Odd Cycle in a Directed Graph
Medium6
Graph, BFS+1
No attempts yet
Time limit
3s
Memory limit
256 MB
Judgeable
Interpreter
Medium6
Simulation, Implementation+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
The Agglomerator
Medium6
Simulation, Math+1
No attempts yet
Time limit
3s
Memory limit
256 MB
Judgeable
Dance Recital
Medium6
Dynamic programming, Bit manipulation
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Kitchen Measurements
Medium6
Shortest path, Graph
No attempts yet
Time limit
3s
Memory limit
256 MB
Judgeable
Vegetables left outside the fence
Medium6
Geometry, Sorting
No attempts yet
Time limit
3s
Memory limit
256 MB
Judgeable
Ultimate Tic-Tac-Toe
Medium6
Game theory, Brute force+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Binary Game
Medium6
Queue, Math
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Perfect Duet
Medium6
Dynamic programming
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Probability Experiment
Medium6
Two pointers, Combinatorics+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Monsters
Medium6
Probability, Dynamic programming
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
CYK's very fun graph building game
Medium6
Dynamic programming, Combinatorics+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Loda Teleportations
Medium6
Dynamic programming, String matching+1
No attempts yet
Time limit
1s
Memory limit
64 MB
Judgeable
Average Voodoo Doll Price
Medium6
Prefix sum, Divide and conquer+1
No attempts yet
Time limit
2s
Memory limit
64 MB
Judgeable

Title	Level	Topics	Solved	Time limit	Memory limit	Judge
Cow HopscotchCount paths from the top-left to the bottom-right cell that step strictly down and right onto a different value, modulo 1000000007.	Medium6	Dynamic programmingPrefix sum+1	No attempts yet	1s	256 MB	Judgeable
SuperbullPick N minus 1 pairings that connect all team IDs into one group so the sum of pairwise XOR values is as large as possible.	Medium6	Minimum spanning treeGraph+1	No attempts yet	1s	256 MB	Judgeable
Picky EaterCut the convex polygon along one diagonal between nonadjacent vertices and eat the largest piece that contains no olive.	Medium6	GeometryBrute force+1	No attempts yet	1s	512 MB	Judgeable
Bessie's Birthday BuffetChoose patches of strictly increasing quality and walk between them to maximize total quality gained minus E per step.	Medium6	Dynamic programmingShortest path+1	No attempts yet	1s	256 MB	Judgeable
Trapped in the HaybalesThe solver sorts bales by position, expands each gap while a neighbor is smaller than the open width, and sums the widths that never reach an end.	Medium6	Two pointersSorting+1	No attempts yet	1s	256 MB	Judgeable
Cutting CheeseCut a 100 mm cube with spherical holes into s slices of equal cheese volume perpendicular to the z axis and print each thickness.	Medium6	Binary searchGeometry+1	No attempts yet	3s	256 MB	Judgeable
Ship TrafficFind the longest subinterval of start times in [t1, t2] during which a northbound ferry avoids every moving ship in each lane.	Medium6	IntervalsSorting+1	No attempts yet	3s	256 MB	Judgeable
Window ManagerSimulate a phone window manager that opens, closes, resizes, and moves non-overlapping rectangles with cascading pushes and reports errors.	Medium6	SimulationGeometry	No attempts yet	2s	256 MB	Judgeable
Sky CitiesAdd the fewest bridges so the connected cities stay connected after any single bridge fails, and print the pairs fixed by the leaf-pairing rule.	Medium6	DFSGraph+1	No attempts yet	1s	256 MB	Judgeable
Coin Toss GameGiven K rounds of a turn-taking coin game that stops once the result is settled, decide for each query whether the score pair can be the final score.	Medium6	MathImplementation	No attempts yet	1s	256 MB	Judgeable
TreeSupport parent changes, path recoloring, and distinct-color path queries on a dynamic rooted tree.	Medium6	TreeBrute force+1	No attempts yet	3s	256 MB	Judgeable
Interval CompositionFind the maximum length L such that each of the two lowercase strings has a contiguous block of length L with the same letter counts.	Medium6	Prefix sumHash map+1	No attempts yet	1s	256 MB	Judgeable
CarpetsDecide whether the given carpets, each usable rotated, cover a W by H room exactly with no overlap.	Medium6	BacktrackingRecursion	No attempts yet	1s	256 MB	Judgeable
Upside-down primeCheck whether N and its 180-degree rotation are both prime, where digits 3, 4 and 7 make the rotation invalid.	Medium6	Number theoryImplementation	No attempts yet	3s	256 MB	Judgeable
NAFTAFor each K from 1 to S, drill up to K whole columns to drain every touched oil pool and maximize the collected oil.	Medium6	Dynamic programmingIntervals+1	No attempts yet	2s	512 MB	Judgeable
SnakeA snake that never shrinks grows one cell per second on a square board and turns on schedule; report when it leaves the board or bites its own body.	Medium6	GeometrySimulation	No attempts yet	1s	256 MB	Judgeable
Speak your mind!Find the fewest words needed to write an integer as signed powers of two joined by four-word sums and differences.	Medium6	Dynamic programmingMath	No attempts yet	2s	256 MB	Judgeable
Ancient symbolGiven an integer x from -1000 to 1000, decode the relic's embedded secret to decide what to print.	Medium6	SimulationImplementation+2	No attempts yet	1s	2 MB	Judgeable
King of penaltyPick the largest set of jobs that finishes before minute P, then order them longest first with idle waiting so the submission times sum to the maximum.	Medium6	GreedySorting	No attempts yet	1s	16 MB	Judgeable
Potemkin cycleFind an induced cycle of length at least four in an undirected graph and print the canonically smallest one, or print no.	Medium6	GraphBFS+1	No attempts yet	1s	256 MB	Judgeable
Ice Hockey World ChampionshipCount the subsets of up to 40 ticket prices whose total is at most M.	Medium6	Divide and conquerSorting+1	No attempts yet	1s	1024 MB	Judgeable
Calvinball Championship Team AssignmentAssign n players to the fewest teams so no rival pair shares a team, breaking ties by lexicographically smallest team numbers.	Medium6	BacktrackingGraph+1	No attempts yet	1s	256 MB	Judgeable
Calvinball team divisionColor up to 14 players with the fewest teams so rivals differ, breaking ties by the smallest team-number sequence.	Medium6	GraphBacktracking+1	No attempts yet	1s	256 MB	Judgeable
Deque Sort 2Place each number at the front or back of an existing deque or into a new one so the deques join into ascending order with the fewest deques.	Medium6	Dynamic programmingSorting+1	No attempts yet	1s	256 MB	Judgeable
Catching EggsCount the homes inside each of m axis-parallel rectangles and print the total over all days per test case.	Medium6	Prefix sumSorting+1	No attempts yet	5s	256 MB	Judgeable
Contest Pizza CuttingFind the largest number of equal radial slices of a circle that each contain the same number of given points with no cut passing through a point.	Medium6	GeometryBrute force+1	No attempts yet	1s	256 MB	Judgeable
Apples and BananasPick a path from the top left to the bottom right using right, down, and diagonal steps to maximize apples left below plus bananas left above.	Medium6	Dynamic programmingPrefix sum	No attempts yet	1s	256 MB	Judgeable
Merging FilesCompute the cheapest way to merge consecutive chapter files when each merge costs the sum of the two parts.	Medium6	Dynamic programmingIntervals+1	No attempts yet	2s	256 MB	Judgeable
Circuit CountingCount the nonempty subsets of up to 40 given plane vectors whose sum is the zero vector.	Medium6	Divide and conquerHash map	No attempts yet	2s	256 MB	Judgeable
Safe PassageMove all students from the gate to the dorm alone or in pairs at the slower pace, with someone carrying the cloak back each time, in minimum total time.	Medium6	GreedySorting+1	No attempts yet	2s	256 MB	Judgeable
Undetected RouteFind how many leading sensors can stay active before their overlapping circles join the left and right walls and block travel from the bottom edge to the top.	Medium6	Union-findBinary search+2	No attempts yet	2s	256 MB	Judgeable
Save the computerSpend a fixed budget on spare parts to maximize the product of per-part Poisson survival probabilities.	Medium6	Dynamic programmingMath	No attempts yet	1s	256 MB	Judgeable
Free WillyApply at most L of the given position permutations to turn the start word into the target word with the fewest steps.	Medium6	BFSGraph+1	No attempts yet	5s	256 MB	Judgeable
Eight puzzleFind the fewest slides that turn each given 3 by 3 board into the goal layout, or report impossible.	Medium6	BFSShortest path+1	No attempts yet	1s	256 MB	Judgeable
Sleeping at WorkSleep exactly M of N minutes in runs of at most R to maximize energy, with the k-th minute of a run worth k times its value.	Medium6	Dynamic programming	No attempts yet	1s	256 MB	Judgeable
Boss RushFind how many bosses from the front can each receive one allowed laser, rocket and psiotic weapon when every weapon has two copies.	Medium6	GraphBinary search	No attempts yet	1s	256 MB	Judgeable
Special ServicesAccept or reject each booking and cancellation by checking whether the employees can cover every active qualification demand.	Medium6	GraphSimulation	No attempts yet	3s	256 MB	Judgeable
Traveling CellspersonStart at S on an X by Y grid of open cells, visit every cell and return to S in the fewest steps, then print LOL once.	Medium6	MathGraph	No attempts yet	1s	256 MB	Judgeable
FiredChoose one employee to fire so the cascade of staff left with no managers saves at least C with the smallest excess, breaking ties by larger number.	Medium6	GraphBFS+1	No attempts yet	1s	256 MB	Judgeable
GG NO RE OMG CHEATZFind the fewest extra attacker units that lift the dice-battle win chance to at least 75 percent.	Medium6	Dynamic programmingProbability+1	No attempts yet	3s	256 MB	Judgeable
Herding SheepAssign every sheep to a barn holding at most K sheep to minimize the longest walk, and print the squared optimum.	Medium6	Binary searchGraph	No attempts yet	2s	256 MB	Judgeable
PaintballAssign each of N players a visible neighbor as target so every player is hit exactly once, choosing the lexicographically smallest such assignment.	Medium6	GraphGreedy	No attempts yet	1s	256 MB	Judgeable
Getting Rid of CoinsPay exactly price P with 1, 5, 10 and 25 cent coins to use as many coins as possible, or report Impossible.	Medium6	GreedyMath+1	No attempts yet	1s	256 MB	Judgeable
Restaurant OrdersGiven menu prices and several order totals, rebuild the exact item multiset behind each total, or report Impossible or Ambiguous.	Medium6	Dynamic programming	No attempts yet	1s	256 MB	Judgeable
Vacuum TubesChoose two disjoint tube pairs that fit within lengths L1 and L2 so the combined length is as large as possible.	Medium6	SortingTwo pointers+1	No attempts yet	1s	256 MB	Judgeable
Chicken JoggersPlace the fewest extra lamps so every trail a jogger who starts at intersection 1 and returns after exactly S meters could use has a lamp on one end.	Medium6	Dynamic programmingTree+1	No attempts yet	1s	256 MB	Judgeable
Forest HighwayCompute the area of the part of a simple polygon lying at distance at least d from a given infinite line.	Medium6	Geometry	No attempts yet	1s	256 MB	Judgeable
Cow CraneDecide whether a crane starting at 0 with speed 1 can carry each of two cows from its start to its target by its deadline while holding one cow at a time.	Medium6	Brute forceGreedy+2	No attempts yet	1s	256 MB	Judgeable
TomosynthesisGiven N disjoint disks, find the widest angle range over which their parallel projections stay pairwise disjoint.	Medium6	GeometryIntervals+1	No attempts yet	1s	256 MB	Judgeable
ProteinsInsert the fewest letters into a DNA string so reading it in blocks of three from the start yields at least n ATG blocks.	Medium6	Dynamic programmingGreedy+1	No attempts yet	1s	256 MB	Judgeable
Absurdistan Roads IIIEach city picks one of its incident roads so every road is picked once and the resulting neighbor list is lexicographically smallest.	Medium6	GraphGreedy+1	No attempts yet	2s	256 MB	Judgeable
A1 PaperCombine the given smaller sheets into one A1 sheet with the least tape, or report impossible.	Medium6	GreedyMath	No attempts yet	1s	256 MB	Judgeable
Magic CheckerboardFill empty cells so rows and columns increase strictly and diagonal neighbors differ in parity with the smallest total sum, or output -1.	Medium6	Dynamic programmingMath+1	No attempts yet	5s	256 MB	Judgeable
Zig Zag NametagGiven k, print the shortest lowercase string with adjacent letter differences summing to k, smallest alphabetically on ties.	Medium6	GreedyString+1	No attempts yet	1s	256 MB	Judgeable
Watering the Flower GardenPlace the fewest sprinklers so water spreading along shared rows and columns reaches every flower.	Medium6	Union-findGraph	No attempts yet	1s	256 MB	Judgeable
Uniting the Three KingdomsFill the fewest sea cells so the three land groups on the grid join into one connected region.	Medium6	BFSGraph+1	No attempts yet	1s	256 MB	Judgeable
Adjoin the NetworksJoin the forest of cable trees with the fewest new links so the connected network has the smallest possible diameter, and report that diameter.	Medium6	TreeGreedy+2	No attempts yet	1s	256 MB	Judgeable
Floppy MusicDecide if every drive head can cover its required sound intervals by moving steadily without a forced turn or stray sound.	Medium6	Dynamic programmingIntervals	No attempts yet	1s	256 MB	Judgeable
MarkleftThe program converts each input line with nested markup rules for uppercase, quote escaping, decimal to hex, reversal, and verbatim copying.	Medium6	StackString+1	No attempts yet	1s	256 MB	Judgeable
Above or Below the Koch CurveGiven a level L Koch curve from (0,0) to (1,0), decide whether each query point lies above or below the curve.	Medium6	RecursionGeometry+1	No attempts yet	1s	256 MB	Judgeable
Frogs With StylesFind the route from pad 0 to pad 1 that uses the fewest jumps within range D and, among those, maximizes its shortest jump.	Medium6	Shortest pathGraph+1	No attempts yet	1s	256 MB	Judgeable
DepactingDecode a nested Pact structure with run-length repeats and omitted record fields, then answer value queries on it.	Medium6	RecursionString+1	No attempts yet	1s	256 MB	Judgeable
LandlockedFor each country letter on the grid, find the smallest number of country borders an 8-direction path crosses to reach water.	Medium6	Shortest pathBFS+2	No attempts yet	2s	256 MB	Judgeable
Smallest Hex MultipleFind the smallest multiple of N whose base-16 representation uses only the allowed digits, or report that none exists.	Medium6	BFSGraph+2	No attempts yet	2s	256 MB	Judgeable
Addition AfflictionReorder each sum so numbers that pair to a multiple of 10 come first in adjacent pairs, using the most pairs and the smallest lexicographic order.	Medium6	GreedyMath+1	No attempts yet	1s	256 MB	Judgeable
ImplicationGiven formulas assumed true, decide for each query formula whether it holds under every assignment that satisfies all assumptions.	Medium6	Brute forceBit manipulation+1	No attempts yet	2s	256 MB	Judgeable
4×n TilingCount the ways to tile a 4 by N board with 1 by 3 and 3 by 1 trominoes modulo 1000000007 for each test case.	Medium6	Dynamic programmingBit manipulation	No attempts yet	2s	256 MB	Judgeable
Coin Turning GameGiven a row of heads and tails, decide if the first player wins the interval-flip game and report the smallest winning first move.	Medium6	Game theoryDynamic programming+2	No attempts yet	2s	256 MB	Judgeable
Assigning Work with Penalty PointsDistribute K extra job slots among N employees to complete as many of M jobs as possible, where each employee handles only listed jobs.	Medium6	Graph	No attempts yet	3s	256 MB	Judgeable
Hole in the WallFind the largest strictly interior rectangle whose border runs only along domino edges, breaking area ties by lexicographic coordinates.	Medium6	MatrixBrute force	No attempts yet	3s	256 MB	Judgeable
Red RectanglesCount the subrectangles of an N by M red and blue grid that contain only red cells.	Medium6	StackDynamic programming+1	No attempts yet	1s	512 MB	Judgeable
Binomial coefficient 4Given N up to 10^18, K, and a prime M up to 2000, compute C(N, K) modulo M.	Medium6	Number theoryCombinatorics	No attempts yet	1s	256 MB	Judgeable
Buying Books 3Stores ship limited copies to buyers at per-copy fees, so move the most copies possible at the lowest total fee.	Medium6	GraphShortest path	No attempts yet	1s	256 MB	Judgeable
Minimizing the LCMFind the smallest N of at least 1 that minimizes the least common multiple of A+N and B+N.	Medium6	Number theoryMath	No attempts yet	1s	256 MB	Judgeable
Railway TicketsCount station pairs where every leg has a free seat but no single seat stays free for the whole trip.	Medium6	IntervalsSorting+1	No attempts yet	1s	256 MB	Judgeable
Farthest node in a weighted treeFor every node of a weighted tree with up to 50000 nodes, print its distance to the farthest node.	Medium6	TreeDFS	No attempts yet	1s	256 MB	Judgeable
Currency ConversionSchedule at most b bank exchanges to meet dated purchase needs while maximizing daily holding rewards minus trip costs.	Medium6	Dynamic programmingPrefix sum	No attempts yet	1s	256 MB	Judgeable
Sum of Squares of Fibonacci NumbersRead n up to 1e18 and print the sum of squared Fibonacci numbers F_0 through F_n modulo 1,000,000,007.	Medium6	MathMatrix+1	No attempts yet	1s	256 MB	Judgeable
Colby's Costly CollectiblesCount the unit triangles inside a simple polygon traced by axis moves on a triangular grid.	Medium6	GeometryMath	No attempts yet	1s	256 MB	Judgeable
Chasing the CheetahsGiven start times and speeds from one spot, find the smallest gap between the first and last cheetah at any time after all have started.	Medium6	Binary searchMath	No attempts yet	3s	256 MB	Judgeable
Jumping YoshiStarting from the first pebble, follow jumps allowed when two spot counts sum to their distance and report the farthest reachable pebble.	Medium6	GraphBFS+1	No attempts yet	2s	256 MB	Judgeable
Lunch MenuCount quadruples of one soup, one main, one dessert and one drink whose prices sum to at most L.	Medium6	SortingTwo pointers+1	No attempts yet	3s	256 MB	Judgeable
Plankton FoodDecide whether chained food trades starting from a surplus type can produce an unbounded amount of a needed type.	Medium6	Shortest pathGraph	No attempts yet	5s	256 MB	Judgeable
ConcatenationCount distinct strings formed by joining a nonempty prefix of the first word with a nonempty suffix of the second word.	Medium6	String matchingCombinatorics	No attempts yet	2s	256 MB	Judgeable
Drink ResponsiblyDecide whether whole numbers of up to eight drinks can total exactly m in cost and u in alcohol, and print the lexicographically smallest purchase.	Medium6	Dynamic programmingMath	No attempts yet	1s	256 MB	Judgeable
Equilibrium StateCompute the equilibrium positions of spring-connected objects in the plane from fixed points, spring strengths, and connections.	Medium6	MathMatrix	No attempts yet	1s	256 MB	Judgeable
Odd Cycle in a Directed GraphGiven a directed graph, decide whether it contains an odd directed cycle and output the smallest vertex of a strongly connected component that holds one.	Medium6	GraphBFS+1	No attempts yet	3s	256 MB	Judgeable
InterpreterRun small integer programs with arithmetic, comparisons, if/else branches, while loops, and print statements.	Medium6	SimulationImplementation+2	No attempts yet	1s	256 MB	Judgeable
The AgglomeratorSimulate moving circular droplets that merge on contact with area-weighted position and velocity, and report the final count and last merge time.	Medium6	SimulationMath+1	No attempts yet	3s	256 MB	Judgeable
Dance RecitalReorder the given routines so the total number of dancers shared by consecutive routines is as small as possible.	Medium6	Dynamic programmingBit manipulation	No attempts yet	1s	256 MB	Judgeable
Kitchen MeasurementsFind the least total volume poured between cups of given capacities to leave exactly V units in the largest cup, or report impossible.	Medium6	Shortest pathGraph	No attempts yet	3s	256 MB	Judgeable
Vegetables left outside the fenceSum the indices of up to 100000 points that lie outside a given axis-aligned simple polygon with up to 100000 vertices.	Medium6	GeometrySorting	No attempts yet	3s	256 MB	Judgeable
Ultimate Tic-Tac-ToeGiven a partially played shrinking-board tic-tac-toe position, output the lexicographically smallest optimal next move under optimal play.	Medium6	Game theoryBrute force+1	No attempts yet	1s	256 MB	Judgeable
Binary GameRead two binary strings and decide whether the first can reach the second by deleting the front character or appending the current parity bit.	Medium6	QueueMath	No attempts yet	1s	256 MB	Judgeable
Perfect DuetTwo singers split the pitch sequence in order so the sum of each singer's consecutive pitch jumps is as small as possible.	Medium6	Dynamic programming	No attempts yet	2s	256 MB	Judgeable
Probability ExperimentCount the triples of given points on a circle that form an acute triangle.	Medium6	Two pointersCombinatorics+1	No attempts yet	1s	256 MB	Judgeable
MonstersThree monster colors eat each other in a cycle when random mixed pairs meet, and you compute each color's chance to be the last one standing.	Medium6	ProbabilityDynamic programming	No attempts yet	2s	256 MB	Judgeable
CYK's very fun graph building gameCount colorings of N vertices with K colors plus edge sets where each vertex points to at most one smaller vertex of a different color, modulo 1000000007.	Medium6	Dynamic programmingCombinatorics+1	No attempts yet	1s	256 MB	Judgeable
Loda TeleportationsGiven N strings in order, find the longest subsequence where each earlier string is both a prefix and a suffix of the later one.	Medium6	Dynamic programmingString matching+1	No attempts yet	1s	64 MB	Judgeable
Average Voodoo Doll PriceCount the contiguous runs of days whose average doll price is at least P.	Medium6	Prefix sumDivide and conquer+1	No attempts yet	2s	64 MB	Judgeable