Problems

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Total results29,252 problems

Maze Stretching
Medium7
Binary search, Shortest path+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Lucky Cities
Medium7
Graph, DFS+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Cave Exploration
Medium7
Simulation, Geometry+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Alibaba
Medium7
Dynamic programming, Greedy+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Changyoung's Password
Medium7
Number theory, Math+1
No attempts yet
Time limit
5s
Memory limit
128 MB
Judgeable
Sentry Robots
Medium7
Graph, Union-find+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Stylish
Medium7
Math, Simulation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Let There Be Light
Medium7
Geometry, Bit manipulation+2
No attempts yet
Time limit
5s
Memory limit
128 MB
Judgeable
Beautiful Layout
Medium7
Binary search, Greedy+1
No attempts yet
Time limit
5s
Memory limit
128 MB
Judgeable
Locks and Keys
Medium7
DFS, Graph+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Darts
Medium7
Dynamic programming, Probability+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Villages on a Highway
Medium7
Backtracking, Combinatorics+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Awkward Lights
Medium7
Math, Bit manipulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
The Two Men of the Japanese Alps
Medium7
Shortest path, Graph+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Find the Multiples
Medium7
Math, Hash map+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Swimming Jam
Medium7
Simulation, Queue+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Traveling Cube
Medium7
BFS, Simulation+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Top Spinning
Medium7
Geometry, Math+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Common Polynomial
Medium7
Math, Recursion+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Zigzag
Medium7
Combinatorics, Geometry+2
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
Jeju Island
Medium7
Geometry, Binary search+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
The Teacher's Side of Math
Medium7
Math, Number theory+1
No attempts yet
Time limit
5s
Memory limit
128 MB
Judgeable
How I Mathematician Wonder What You Are!
Medium7
Geometry, Intervals+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Power Calculus
Medium7
Dynamic programming, Math+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
The Best Name for Your Baby
Medium7
Dynamic programming, String+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Network Mess
Medium7
Tree, Graph+2
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
Bingo
Medium7
Brute force, Combinatorics+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Dice Puzzle
Medium7
Backtracking, Simulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Concert Hall Scheduling
Medium7
Dynamic programming, Greedy+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Mystery
Medium7
String, Math+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Battleship
Medium7
Simulation, Brute force+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Riding Roller Coasters
Medium7
Dynamic programming, Greedy+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Magic Star
Medium7
Backtracking, Brute force+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Last Minute Constructions
Medium7
Graph, DFS+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
The Two-ball Game
Medium7
Geometry, Graph+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
To Score or Not to Score
Medium7
Implementation, Backtracking+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Choosing Numbers
Medium7
Sorting, Sliding window+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Exact Measurement
Medium7
Dynamic programming, Greedy+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Hyperdrome
Medium7
Bit manipulation, Prefix sum+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
The Minotaur's Labyrinth
Medium7
Graph, BFS+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Sentries
Medium7
Greedy, Intervals+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Coloring the Table
Medium7
Math, Combinatorics+2
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Roads
Medium7
Graph, Minimum spanning tree+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Mobile
Medium7
Tree, Greedy+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Parencedence!
Medium7
Game theory, Dynamic programming+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Sofa, So Good
Medium7
Dynamic programming, Bit manipulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
The Banzhaf Buzz-Off
Medium7
Dynamic programming, Combinatorics+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
GPS I Love You
Medium7
Graph, Shortest path+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Cut It Out!
Medium7
Geometry, Hash map+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
We've Got Chemistry, Babe
Medium7
Math, Number theory+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Tensor Product of Matrices
Medium7
Math, Number theory+2
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
Trip the Lights Fantastic
Medium7
Graph, Shortest path+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Bordering on Madness
Medium7
Geometry, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
The Worm Turns
Medium7
DFS, Brute force+2
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
You'll be Working on the Railroad
Medium7
Graph, Shortest path+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
A Foldy but a Goody
Medium7
Recursion, Divide and conquer+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Give Me an E
Medium7
Math, Combinatorics+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Mahershalalhashbaz, Nebuchadnezzar, and Billy Bob Benjamin Go to the Regionals
Medium7
Greedy, Sorting+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Mastermind: The Best Next Guess
Medium7
Brute force, Simulation+2
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
Abbreviations
Medium7
Dynamic programming, String+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Making Rectangles
Medium7
Number theory, Brute force+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Robot Navigation
Medium7
BFS, Graph+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Burnout
Medium7
Recursion, Simulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Family Fortune
Medium7
Dynamic programming, Tree+1
No attempts yet
Time limit
10s
Memory limit
128 MB
Judgeable
Moving Points
Medium7
Dynamic programming, Geometry+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Counting Bits
Medium7
Dynamic programming, Bit manipulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Equal Angles
Medium7
Geometry, Math+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
The Heart of the Country
Medium7
Graph, Greedy+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Lawrence of Arabia
Medium7
Dynamic programming, Prefix sum+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Bridges and Tunnels
Medium7
Graph, Shortest path+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Making a Tetrahedron
Medium7
Geometry, Sorting+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Cookie Crumbs
Medium7
Geometry, Union-find+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
How Big Is It?
Medium7
Backtracking, Geometry+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Octagons
Medium7
Math, String+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Party Location
Medium7
Geometry, Brute force+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Largest Square
Medium7
Binary search, Prefix sum+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
The Thirty-One Game
Medium7
Game theory, Dynamic programming+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Large Number Prime Factorization
Medium7
Number theory, Math+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
The Knight's Journey
Medium7
Math, Greedy+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Shopping
Medium7
Graph, Shortest path+2
No attempts yet
Time limit
3s
Memory limit
128 MB
Judgeable
Rooks
Medium7
Greedy, Brute force+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Slalom
Medium7
Binary search, Math+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Ocean Currents
Medium7
Graph, Shortest path+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Colliding Traffic
Medium7
Geometry, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Zerg Rush!!!
Medium7
Simulation, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Classified
Medium7
Graph, Topological sort+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Hot Spot
Medium7
BFS, Graph+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Shortest Flight Path
Medium7
Graph, Shortest path+2
No attempts yet
Time limit
5s
Memory limit
128 MB
Judgeable
Stacking Bowls
Medium7
Dynamic programming, Greedy+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Garbage Chute
Medium7
Geometry, Brute force+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Love and War
Medium7
Graph, Union-find+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Friend or Foe?
Medium7
Geometry, Math+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Non-monotonicity
Medium7
Dynamic programming, Array+2
No attempts yet
Time limit
10s
Memory limit
128 MB
Judgeable
Texas Trip
Medium7
Geometry, Binary search+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Prime-Free Sequence
Medium7
Backtracking, DFS+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Hit or Miss
Medium7
Simulation, Queue+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Choosing the Final Die's Face Values
Medium7
Dynamic programming, Prefix sum+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Polly Nomials
Medium7
Dynamic programming, Math+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Galactic Breakup
Medium7
Union-find, Graph+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Preorder and Postorder
Medium7
Tree, Dynamic programming+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable

Title	Level	Topics	Solved	Time limit	Memory limit	Judge
Maze StretchingGiven a maze and target shortest-path length L, find the vertical stretch factor X so that the minimum-cost path (with horizontal steps costing 1 and vertical steps costing X) equals L exactly, using binary search over X combined with shortest-path computation.	Medium7	Binary searchShortest path+1	No attempts yet	1s	128 MB	Judgeable
Lucky CitiesGiven an undirected graph, count vertices that lie on at least one simple cycle of odd length.	Medium7	GraphDFS+1	No attempts yet	1s	128 MB	Judgeable
Cave ExplorationSimulate a maze-runner who always turns left when possible on a grid of horizontal and vertical corridors until he returns to the start, then count unvisited corridors.	Medium7	SimulationGeometry+1	No attempts yet	1s	128 MB	Judgeable
AlibabaGiven points on a line with deadlines, find the minimum finishing time to visit all points starting from an optimally chosen point, respecting each point's deadline, or report impossibility.	Medium7	Dynamic programmingGreedy+1	No attempts yet	1s	128 MB	Judgeable
Changyoung's PasswordGiven the prime factorization of a huge n, compute the sum of a+b over all unordered pairs with lcm(a,b)=n, modulo 1e9+7.	Medium7	Number theoryMath+1	No attempts yet	5s	128 MB	Judgeable
Sentry RobotsGroup points of interest into row and column segments split by obstacles and find the minimum vertex cover of the resulting bipartite graph via maximum matching.	Medium7	GraphUnion-find+1	No attempts yet	1s	128 MB	Judgeable
StylishDetermine unknown bracket-indentation weights from a correctly indented program and use them to compute (or mark unsolvable) indentation for each line of another program.	Medium7	MathSimulation+1	No attempts yet	1s	128 MB	Judgeable
Let There Be LightGiven up to 2000 balloons blocking up to 15 point lights from a target point, choose at most R balloons to remove to maximize total illumination, computed via geometric occlusion and a min-cut/greedy set-cover style optimization over light-blocking sets, printed as an exact fraction.	Medium7	GeometryBit manipulation+2	No attempts yet	5s	128 MB	Judgeable
Beautiful LayoutGiven word lengths and page width W, determine how to break the words into justified rows so that the maximum consecutive blank run is minimized, and output that minimum value.	Medium7	Binary searchGreedy+1	No attempts yet	5s	128 MB	Judgeable
Locks and KeysDetermine reachability on a tree with colored locks and single-use keys held one at a time, requiring a search over reachable key/room states.	Medium7	DFSGraph+1	No attempts yet	2s	128 MB	Judgeable
DartsCompute win probabilities up to score 501 for two darts players with different throw distributions, where B optimizes target section each turn.	Medium7	Dynamic programmingProbability+2	No attempts yet	1s	128 MB	Judgeable
Villages on a HighwayGiven all pairwise distances between N villages on a line, reconstruct every possible set of consecutive gaps that reproduces exactly that multiset of distances.	Medium7	BacktrackingCombinatorics+1	No attempts yet	1s	128 MB	Judgeable
Awkward LightsGiven a grid where toggling a switch flips lights at a fixed Manhattan distance, decide over GF(2) whether all lights can be turned off simultaneously.	Medium7	MathBit manipulation+2	No attempts yet	1s	128 MB	Judgeable
The Two Men of the Japanese AlpsGiven a polyline route where both endpoints have equal, minimal altitude, find the minimum total arc length two climbers must travel, always keeping equal altitude, until they meet at a common point.	Medium7	Shortest pathGraph+1	No attempts yet	1s	128 MB	Judgeable
Find the MultiplesCount index pairs (i,j) with a_i nonzero such that the decimal number formed by a_i...a_j is divisible by a given prime Q, for a pseudo-randomly generated digit sequence of length up to 1e5.	Medium7	MathHash map+2	No attempts yet	2s	128 MB	Judgeable
Swimming JamSimulate multiple swimmers sharing two lanes with blocking and end-of-lane reordering rules to compute the total time until everyone finishes their assigned laps.	Medium7	SimulationQueue+1	No attempts yet	1s	128 MB	Judgeable
Traveling CubeSimulate a color-coded rolling cube on a grid that must visit six colored squares in a given order while avoiding black squares, and find the minimum number of rolls.	Medium7	BFSSimulation+1	No attempts yet	1s	128 MB	Judgeable
Top SpinningGiven a closed path of line segments and circular arcs describing a cardboard cutout, compute the exact centroid of the enclosed shape and determine whether the centroid lies inside the shape.	Medium7	GeometryMath+1	No attempts yet	1s	128 MB	Judgeable
Common PolynomialParse two polynomial expressions with parentheses and exponents, expand them, then compute and print the normalized greatest common divisor polynomial.	Medium7	MathRecursion+1	No attempts yet	1s	128 MB	Judgeable
ZigzagGiven up to 10 points on a small grid, find a polyline of collinear-point segments covering all points with the fewest bends, then minimal total length among such solutions.	Medium7	CombinatoricsGeometry+2	No attempts yet	3s	128 MB	Judgeable
Jeju IslandGiven a convex polygon, find the point maximizing distance to the boundary using ternary search or half-plane shrinking, and output that maximum distance.	Medium7	GeometryBinary search+1	No attempts yet	1s	128 MB	Judgeable
The Teacher's Side of MathGiven t = a^(1/m) + b^(1/n) for distinct primes a, b, compute the minimal polynomial over the integers of degree mn using resultant-style elimination.	Medium7	MathNumber theory+1	No attempts yet	5s	128 MB	Judgeable
How I Mathematician Wonder What You Are!Determine whether a given simple polygon is star-shaped by computing the intersection of half-planes defined by its edges (kernel of polygon).	Medium7	GeometryIntervals+1	No attempts yet	1s	128 MB	Judgeable
Power CalculusFind the minimum number of multiplications and divisions (using addition chains with subtraction allowed, keeping intermediate exponents positive) needed to build x^n for n up to 1000.	Medium7	Dynamic programmingMath+1	No attempts yet	1s	128 MB	Judgeable
The Best Name for Your BabyGiven a context-free grammar-like rewriting rule set, find the lexicographically smallest terminal string of exactly length l derivable from start symbol S.	Medium7	Dynamic programmingString+2	No attempts yet	1s	128 MB	Judgeable
Network MessReconstruct a tree with given leaf-to-leaf distances and output the degrees of internal switch nodes in ascending order.	Medium7	TreeGraph+2	No attempts yet	3s	128 MB	Judgeable
BingoFind the shortest number sequence a gamemaster can announce so bingo cards complete in non-decreasing order of their fixed index, or report impossibility.	Medium7	Brute forceCombinatorics+1	No attempts yet	1s	128 MB	Judgeable
Dice PuzzleGiven partial top and front faces of a 3x3x3 cube of standard dice with fixed chirality and opposite-face contact constraints, enumerate all valid orientations and report every possible sum of the right-side faces.	Medium7	BacktrackingSimulation+2	No attempts yet	1s	128 MB	Judgeable
Concert Hall SchedulingGiven up to 1000 interval requests with prices for two identical rooms over 365 days, select accepted intervals (assignable to either of 2 rooms without overlap) to maximize total revenue.	Medium7	Dynamic programmingGreedy+1	No attempts yet	2s	128 MB	Judgeable
MysteryGiven a character set and N integers in [-X, X] where X is one less than the set size, output the unique length-N string those integers encode.	Medium7	StringMath+2	No attempts yet	1s	128 MB	Judgeable
BattleshipGiven two ship maps and a list of unlabeled shots, decide which admiral won under the hit-and-shoot-again turn rules.	Medium7	SimulationBrute force+2	No attempts yet	1s	128 MB	Judgeable
Riding Roller CoastersGiven N coasters with fun a_i-(k-1)^2*b_i per ride and fixed ride times, answer Q queries for the maximum total fun within each time budget.	Medium7	Dynamic programmingGreedy+2	No attempts yet	1s	128 MB	Judgeable
Magic StarFill the twelve cells of a hexagram with distinct numbers 1 to 12 so each of the six lines sums to 26, choosing the lexicographically smallest completion of a partially given star.	Medium7	BacktrackingBrute force+2	No attempts yet	1s	256 MB	Judgeable
Last Minute ConstructionsGiven a forest of undirected roads plus a set of directed tunnels that must all be used, decide whether a simple path exists from a start to an end village that uses exactly those tunnels.	Medium7	GraphDFS+2	No attempts yet	1s	128 MB	Judgeable
The Two-ball GameGiven n points, decide whether two non-crossing paths exist from s1 to t1 and s2 to t2 with no shared vertex.	Medium7	GeometryGraph+1	No attempts yet	1s	128 MB	Judgeable
To Score or Not to ScoreGiven the coordinates of two soccer robot teams, decide whether the team in possession can score a goal that survives the removal of any single teammate.	Medium7	ImplementationBacktracking+2	No attempts yet	1s	128 MB	Judgeable
Choosing NumbersGiven a sequence, delete exactly K elements so that the sum of the largest gap and the smallest adjacent gap among the remaining elements is minimized.	Medium7	SortingSliding window+2	No attempts yet	1s	256 MB	Judgeable
Exact MeasurementEach box offers up to q_i masses of weight 10^k_i; find the fewest boxes to open so the chosen masses sum to exactly x.	Medium7	Dynamic programmingGreedy+2	No attempts yet	1s	128 MB	Judgeable
HyperdromeCount substrings of S whose characters can be rearranged into a palindrome, where only the parity of each letter's count matters.	Medium7	Bit manipulationPrefix sum+2	No attempts yet	2s	128 MB	Judgeable
The Minotaur's LabyrinthFind the smallest empty square, avoiding the two corner cells, whose removal disconnects the top-left entrance from the bottom-right lair.	Medium7	GraphBFS+2	No attempts yet	2s	128 MB	Judgeable
SentriesGiven interval reports saying each range holds no ninja or at least one, find every bush that holds a ninja in all valid placements of exactly K ninjas.	Medium7	GreedyIntervals+2	No attempts yet	1s	256 MB	Judgeable
Coloring the TableCount colorings of an n by m grid, red or blue, where every 2 by 2 block has an odd number of red cells, respecting k fixed cells.	Medium7	MathCombinatorics+2	No attempts yet	2s	256 MB	Judgeable
RoadsDecide whether the graph has a spanning tree with exactly K gravel edges, where each road is gravel or concrete.	Medium7	GraphMinimum spanning tree+2	No attempts yet	1s	128 MB	Judgeable
MobileGiven a full binary tree of rods and toys, find the minimum number of left-right child swaps so that all toys sit at depths differing by at most 1, with deeper toys to the left.	Medium7	TreeGreedy+2	No attempts yet	1s	128 MB	Judgeable
Parencedence!Two players alternately parenthesize one operator of an expression, maximizing and minimizing the value, and two rounds with swapped first movers decide the winner.	Medium7	Game theoryDynamic programming+2	No attempts yet	1s	128 MB	Judgeable
Sofa, So GoodGiven framing and upholstering time matrices, find the minimum-cost framing assignment, then the minimum-cost upholstering assignment, and report each worker's schedule and total idle time.	Medium7	Dynamic programmingBit manipulation+2	No attempts yet	1s	128 MB	Judgeable
The Banzhaf Buzz-OffGiven board members with distinct weights, count for each weight how many winning coalitions make a member with that weight a critical voter.	Medium7	Dynamic programmingCombinatorics+2	No attempts yet	1s	128 MB	Judgeable
GPS I Love YouFind the minimum number of roads to force so that a specified simple route becomes the shortest path favored by the GPS.	Medium7	GraphShortest path+2	No attempts yet	1s	128 MB	Judgeable
Cut It Out!Given n triangular holes and 2n smaller triangles produced by splitting each hole along a cevian, match the two pieces to each hole using side lengths and angles.	Medium7	GeometryHash map+2	No attempts yet	1s	128 MB	Judgeable
We've Got Chemistry, BabeParse chemical formulas into atom counts, then find positive integer coefficients with gcd 1 that balance the reaction, or report that none or many exist.	Medium7	MathNumber theory+2	No attempts yet	1s	128 MB	Judgeable
Tensor Product of MatricesCount how many ways a given positive-integer matrix can be written as a tensor product A ⊗ B where neither factor is 1×1.	Medium7	MathNumber theory+2	No attempts yet	3s	128 MB	Judgeable
Trip the Lights FantasticFind the fastest car route through a town whose traffic lights cycle through green, yellow and red, where arriving on red costs a 5 second stop.	Medium7	GraphShortest path+2	No attempts yet	1s	128 MB	Judgeable
Bordering on MadnessFor each of several offsets, compute the total length and the newly painted area of the rectilinear polygon offset outward by a fixed distance.	Medium7	GeometryImplementation+2	No attempts yet	1s	128 MB	Judgeable
The Worm TurnsFind a start cell and first direction that maximize how many food pieces a self-avoiding worm eats, turning only when blocked.	Medium7	DFSBrute force+2	No attempts yet	3s	128 MB	Judgeable
You'll be Working on the RailroadChoose a simple path from town 0 to town 1 in a weighted graph so that the county pays for all sections except the two most expensive ones, then print the path and the county's cost.	Medium7	GraphShortest path+1	No attempts yet	1s	128 MB	Judgeable
A Foldy but a GoodyFold a paper strip n times by upper and lower folds, unfold it into right angles, and find the coordinates of the m-th point along it.	Medium7	RecursionDivide and conquer+2	No attempts yet	1s	128 MB	Judgeable
Give Me an EFind the n-th positive integer (n below 2^31) whose English spelling contains no letter E, and print it with thousands separators.	Medium7	MathCombinatorics+1	No attempts yet	1s	128 MB	Judgeable
Mahershalalhashbaz, Nebuchadnezzar, and Billy Bob Benjamin Go to the RegionalsDecide whether n given names can be split into teams of exactly k so each team's name lengths all lie within 2 of that team's average.	Medium7	GreedySorting+2	No attempts yet	1s	128 MB	Judgeable
Mastermind: The Best Next GuessGiven prior Mastermind guesses and their black/white peg counts, find the guess that minimizes the largest group of codes still consistent with each possible response.	Medium7	Brute forceSimulation+2	No attempts yet	3s	128 MB	Judgeable
AbbreviationsGiven ignored stopwords, an abbreviation, and a sentence, count the distinct ways to split the abbreviation into pieces matched as subsequences of the meaningful words in order.	Medium7	Dynamic programmingString+2	No attempts yet	1s	128 MB	Judgeable
Making RectanglesFor each N, find the smallest tile count T whose number of unordered factor pairs (a×b rectangles with a≤b) is exactly N.	Medium7	Number theoryBrute force+2	No attempts yet	1s	128 MB	Judgeable
Robot NavigationGiven a grid with craters and a robot that moves and turns, find the shortest command sequence to reach the goal and count how many such sequences exist modulo 1,000,000.	Medium7	BFSGraph+1	No attempts yet	1s	128 MB	Judgeable
BurnoutGiven a nested repeating on/off pattern and a target on-time N, find the elapsed time when total on-time first reaches N.	Medium7	RecursionSimulation+2	No attempts yet	1s	128 MB	Judgeable
Family FortuneChoose K nodes in a rooted tree, no one an ancestor of another, maximizing the sum of weights; print 0 if impossible.	Medium7	Dynamic programmingTree+1	No attempts yet	10s	128 MB	Judgeable
Moving PointsFind the least time for one chaser to intercept N moving targets in order when the chaser is faster than every target.	Medium7	Dynamic programmingGeometry+2	No attempts yet	1s	128 MB	Judgeable
Counting BitsCount integers in [LO, HI] whose number of halving steps under the popcount map reaches 1 in exactly X steps.	Medium7	Dynamic programmingBit manipulation+2	No attempts yet	1s	128 MB	Judgeable
Equal AnglesFor each triangle, compute the two Brocard points, where the angle a point makes with each side in cyclic order stays equal.	Medium7	GeometryMath+1	No attempts yet	1s	128 MB	Judgeable
The Heart of the CountryFind the largest set of vertices in an undirected graph such that each vertex has total troops from itself and its neighbors inside the set at least K, and report the set size and total troops.	Medium7	GraphGreedy+2	No attempts yet	1s	128 MB	Judgeable
Lawrence of ArabiaCut at most M of the N-1 gaps in a line of weighted depots to minimize the sum of products over all still-connected pairs.	Medium7	Dynamic programmingPrefix sum+1	No attempts yet	2s	128 MB	Judgeable
Bridges and TunnelsGiven an undirected weighted graph whose edges are marked indoor or outdoor, answer p queries, each asking for the minimum outdoor time from one building to another, breaking ties by total time.	Medium7	GraphShortest path+2	No attempts yet	1s	128 MB	Judgeable
Making a TetrahedronFor each of up to 10000 sets of six edge lengths, decide whether some assignment to a tetrahedron gives non-zero volume.	Medium7	GeometrySorting+2	No attempts yet	1s	128 MB	Judgeable
Cookie CrumbsGiven a rectangle and up to 100 closed rectangular chips removed from it, count the connected crumbs left.	Medium7	GeometryUnion-find+1	No attempts yet	1s	128 MB	Judgeable
How Big Is It?Given up to 8 circles, arrange them all touching the bottom of a box to minimize the box's total width.	Medium7	BacktrackingGeometry+1	No attempts yet	1s	128 MB	Judgeable
OctagonsGiven words over {a,b,c} describing paths in the labeled (3,3,3,8) octagon tessellation, decide whether each path returns to its start.	Medium7	MathString+1	No attempts yet	1s	128 MB	Judgeable
Party LocationGiven up to 200 house coordinates in a 50 km square, find a party location within 2.5 km of as many houses as possible.	Medium7	GeometryBrute force+2	No attempts yet	1s	128 MB	Judgeable
Largest SquareGiven an N by N grid with W bad cells listed explicitly, find the largest axis-aligned square containing at most L bad cells.	Medium7	Binary searchPrefix sum+2	No attempts yet	2s	128 MB	Judgeable
The Thirty-One GameGiven a prefix of draws in the card game Thirty-One with cards 1 to 6, decide who wins from that position under perfect play with the remaining deck.	Medium7	Game theoryDynamic programming+2	No attempts yet	1s	128 MB	Judgeable
Large Number Prime FactorizationFactorize an integer up to 2^62 into primes and print each prime factor on its own line in increasing order.	Medium7	Number theoryMath+1	No attempts yet	1s	128 MB	Judgeable
The Knight's JourneyFor each target square (x, y) up to 1e9 away, find the smallest number of knight moves needed to reach it from the origin.	Medium7	MathGreedy+2	No attempts yet	1s	128 MB	Judgeable
ShoppingGiven weighted roads and up to 10 stores, find the shortest round trip from house 0 visiting every store.	Medium7	GraphShortest path+2	No attempts yet	3s	128 MB	Judgeable
RooksGiven a 15x15 board of marked squares, find the minimum number of rooks needed so every marked square lies in a chosen row or column.	Medium7	GreedyBrute force+2	No attempts yet	1s	128 MB	Judgeable
SlalomGiven gate pairs at increasing depths and S vertical speeds, find the smallest speed that lets a skier move horizontally fast enough to pass through every gate, and output it or IMPOSSIBLE.	Medium7	Binary searchMath+2	No attempts yet	1s	128 MB	Judgeable
Ocean CurrentsGiven a grid where each cell has a current direction, find the minimum energy to travel between two cells when following the current is free and any other of the eight moves costs one.	Medium7	GraphShortest path+2	No attempts yet	1s	256 MB	Judgeable
Colliding TrafficEach boat moves at constant velocity; find the earliest time at which some pair comes within distance r, or report that no pair ever does.	Medium7	GeometryImplementation+2	No attempts yet	1s	128 MB	Judgeable
Zerg Rush!!!Simulate a grid battle of two Zergling armies over t turns following detailed attack, death, movement, and regeneration rules.	Medium7	SimulationImplementation+2	No attempts yet	1s	128 MB	Judgeable
ClassifiedGiven a partial order with listed A -> B rules and guaranteed pairwise greatest lower bounds, simulate read and write actions that lower a user or document level to the glb of two current levels, printing each result.	Medium7	GraphTopological sort+2	No attempts yet	1s	128 MB	Judgeable
Hot SpotOn a 4 by 4 board, robots jump over one or two adjacent robots into an empty square; find the fewest jumps that bring the red robot to the top-left corner without violating the blue-robot adjacency rule.	Medium7	BFSGraph+2	No attempts yet	1s	128 MB	Judgeable
Shortest Flight PathGiven airports on a sphere, find the shortest route between two airports staying inside the union of radius-R circles and within each fuel leg.	Medium7	GraphShortest path+2	No attempts yet	5s	128 MB	Judgeable
Stacking BowlsGiven several already-sorted stacks of bowls, find the minimum number of split and merge operations to combine them into one globally sorted stack.	Medium7	Dynamic programmingGreedy+2	No attempts yet	1s	128 MB	Judgeable
Garbage ChuteGiven a simple polygon, find the minimum width of a vertical strip it can pass through after being rotated, and print it rounded up to two decimals.	Medium7	GeometryBrute force+2	No attempts yet	1s	128 MB	Judgeable
Love and WarAssign each spouse to a side so couples are split and no affair pair shares Cheolseung's side; output the lexicographically smallest Boram-side seating or bad luck.	Medium7	GraphUnion-find+2	No attempts yet	1s	128 MB	Judgeable
Friend or Foe?Given two sets of 3D points, decide whether a single plane separates the Empire points strictly on the positive side from the Alliance points on the non-positive side.	Medium7	GeometryMath+2	No attempts yet	1s	128 MB	Judgeable
Non-monotonicityGiven a permutation of 1 to n, find the longest subsequence whose elements alternate down, up, down, starting with a decrease.	Medium7	Dynamic programmingArray+2	No attempts yet	10s	128 MB	Judgeable
Texas TripGiven up to 30 lattice points per test case, find the area of the smallest square (any rotation) that covers all of them, printed to two decimals.	Medium7	GeometryBinary search+2	No attempts yet	1s	128 MB	Judgeable
Prime-Free SequenceFind the lexicographically smallest permutation of n..m where sums of any 2 to d consecutive numbers are all non-prime, or report none.	Medium7	BacktrackingDFS+2	No attempts yet	1s	128 MB	Judgeable
Hit or MissSimulate a multi-player solitaire card game and either report the last card each player discarded or declare the position unwinnable.	Medium7	SimulationQueue+2	No attempts yet	1s	128 MB	Judgeable
Choosing the Final Die's Face ValuesEach test case fixes several dice and asks for the r face values of the last die so that m given sums appear with exactly the given counts, choosing the lexicographically smallest set.	Medium7	Dynamic programmingPrefix sum+2	No attempts yet	1s	128 MB	Judgeable
Polly NomialsFor each polynomial with leading coefficient 1, evaluate it at x = 1 or -1 and find the minimum key presses needed to compute it on a left-to-right calculator.	Medium7	Dynamic programmingMath+2	No attempts yet	1s	128 MB	Judgeable
Galactic BreakupGiven three dimensional grid cell labels and the cell lists of the monarchies seceding in a fixed order, count the months after which the remaining cells form two or more pieces.	Medium7	Union-findGraph+1	No attempts yet	1s	128 MB	Judgeable
Preorder and PostorderCount how many m-ary trees share the given pre-order and post-order traversals.	Medium7	TreeDynamic programming+2	No attempts yet	1s	128 MB	Judgeable