Problems

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Total results29,429 problems

Cake
Hard8
Binary search, Greedy+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Sticker Collection
Hard8
Dynamic programming, Bit manipulation+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Magic Marbles
Hard8
Number theory, Combinatorics+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Paper Folding
Hard8
Dynamic programming, Intervals+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Zero Run Pattern
Hard8
String, Binary search+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Islands
Hard8
BFS, Graph+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Flipping
Hard8
BFS, Math+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Shuffle
Hard8
Dynamic programming, Matrix+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Floor Decoration
Hard8
Math, Implementation+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Same Towers
Hard8
Dynamic programming, Array+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Tteokguk
Hard8
Graph, Minimum spanning tree+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Fibonacci Knapsack
Hard8
Dynamic programming, Greedy+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Paper Racing
Hard8
BFS, Graph+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Non-Repeating Word
Hard8
Backtracking, String+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Robot Race
Hard8
BFS, Graph+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Text Message Fees
Hard8
Math, Number theory+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Police Stations
Hard8
Graph, DFS+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Minimum Cost Connected Cells
Hard8
Dynamic programming, Bit manipulation+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Picnic Rhombi
Hard8
Combinatorics, Geometry+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Shadow
Hard8
Geometry, Math+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Toy Sterilization
Hard8
Greedy, Graph+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Bus
Hard8
Greedy, Segment tree+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Increasing List
Hard8
Backtracking, Greedy+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Covering
Hard8
Dynamic programming, Backtracking+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Misheard Binary
Hard8
Dynamic programming, Combinatorics+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Returning to Farming
Hard8
Prefix sum, Hash map+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Number Selection Game
Hard8
Divide and conquer, Math+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Chasing Game
Hard8
Game theory, BFS+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Gloves
Hard8
Bit manipulation, Greedy+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Weather Forecasting
Hard8
Binary search, Dynamic programming+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Coin Passing Game
Hard8
Probability, Dynamic programming+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Count Palindromic Word Sequences
Hard8
Dynamic programming, String matching+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Make a Monotone Sequence
Hard8
Dynamic programming, Greedy+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Boyle's Law
Hard8
Math, Dynamic programming+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Two-Bill Purchase
Hard8
Number theory, Math+2
No attempts yet
Time limit
0.5s
Memory limit
128 MB
Judgeable
Fastest Grid Route
Hard8
Shortest path, Graph+2
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Closest Points
Hard8
Divide and conquer, Geometry+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Magic Stone
Hard8
Combinatorics, Dynamic programming+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Fractions
Hard8
Number theory, Math+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Her Heart
Hard8
BFS, Math+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Colored Balls
Hard8
Heap, Linked list+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
War - Declaration of War
Hard8
Geometry, Shortest path+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Rich Person's Coin Exchange
Hard8
Shortest path, Graph+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
P-Sequences
Hard8
Combinatorics, Dynamic programming+1
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
War - Local Battles
Hard8
Geometry, Math+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Floor Plan
Hard8
Union-find, Geometry+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Cave Exploration
Hard8
Shortest path, Bit manipulation+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Increasing Sequence
Hard8
Dynamic programming, String+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Parking Lot
Hard8
BFS, Binary search+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Building Fences
Hard8
Geometry, Math+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
War - Water Instead of Fire
Hard8
Binary search, Heap+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Merge Words
Hard8
Dynamic programming, Bit manipulation+2
No attempts yet
Time limit
5s
Memory limit
128 MB
Judgeable
Increasing Sequence
Hard8
Dynamic programming, Greedy+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Kruskal's Ball
Hard8
Minimum spanning tree, Union-find+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
This Looks Like an A-Level Problem
Hard8
Number theory, Math+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Do Not Go to School!
Hard8
Graph, BFS+2
No attempts yet
Time limit
2s
Memory limit
160 MB
Judgeable
Protective Tents
Hard8
Greedy, Intervals+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Jinuk's Farm
Hard8
Binary search, Prefix sum+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Quiz Show
Hard8
Dynamic programming, Array+2
No attempts yet
Time limit
5s
Memory limit
128 MB
Judgeable
Network
Hard8
Combinatorics, Tree+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Phone Numbers
Hard8
Greedy, Combinatorics+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Squares
Hard8
Geometry, Prefix sum+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Equal Digit Counts
Hard8
Combinatorics, Backtracking+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Minimum Resistor Network
Hard8
Math, Recursion+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Choosing Guitars
Hard8
Dynamic programming, Game theory+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Nested Reversal Sequence
Hard8
String, Greedy+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Isosceles Triangles
Hard8
Geometry, Combinatorics+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Increasing Arcade Paths
Hard8
Dynamic programming, Combinatorics+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Number Concatenation
Hard8
String matching, Binary search+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Random Sort
Hard8
Probability, Dynamic programming+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Terminal Cities
Hard8
Dynamic programming, Bit manipulation+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Lucky-number Sum
Hard8
Dynamic programming, Greedy+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Polygon Dissection Count
Hard8
Combinatorics, Dynamic programming+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Dance, Dance
Hard8
Graph, Binary search+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Expected Repaints for Balls
Hard8
Probability, Dynamic programming+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Maximum Number of Squares
Hard8
Math, Combinatorics+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Chess Practice
Hard8
Game theory, Dynamic programming+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Tree Planting
Hard8
Combinatorics, Geometry+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Domino Game 2
Hard8
Math, Matrix+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Amazing Maze
Hard8
BFS, Bit manipulation+2
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
P-Array
Hard8
Bit manipulation, Brute force+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Word Rolling
Hard8
Number theory, Math+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Laser
Hard8
Number theory, Math+2
No attempts yet
Time limit
5s
Memory limit
128 MB
Judgeable
Binary Power Bishop
Hard8
Bit manipulation, Math+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Fugitive Monkey
Hard8
Union-find, Shortest path+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Monkey Tower
Hard8
Dynamic programming, Math+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Strategy Game Tournament
Hard8
Graph, Union-find+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Rook Attacks
Hard8
Math, Prefix sum+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Circle Dance
Hard8
Combinatorics, Graph+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Second Smallest Spanning Tree
Hard8
Minimum spanning tree, Tree+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Duel
Hard8
Game theory, Combinatorics+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Minimum Pairing Cost for Two Sets
Hard8
Dynamic programming, Greedy+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Complete Binary Tree
Hard8
Dynamic programming, Tree+2
No attempts yet
Time limit
5s
Memory limit
128 MB
Judgeable
Lattice Convex Polygon
Hard8
Geometry, Dynamic programming+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Taxi
Hard8
Graph, Dynamic programming+2
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Jimin's Farm Tour Season II
Hard8
Graph, Shortest path+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Two-Pan Balance
Hard8
Backtracking, Combinatorics+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Jang Hongjun the Tofu Seller
Hard8
Graph, Shortest path+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Pig Catching
Hard8
Union-find, Graph+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Minimum-Cost Number Matching (Hard)
Hard8
Dynamic programming, Greedy+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable

Title	Level	Topics	Solved	Time limit	Memory limit	Judge
CakeGiven N cake pieces and at most M cuts, split pieces to minimize the gap between the heaviest and lightest resulting piece.	Hard8	Binary searchGreedy+2	No attempts yet	2s	128 MB	Judgeable
Sticker CollectionGiven N stickers with prices and values, some already owned, find the minimum starting money so that after selling and buying, the total value owned reaches at least K.	Hard8	Dynamic programmingBit manipulation+2	No attempts yet	2s	128 MB	Judgeable
Magic MarblesFind the largest number up to M that evenly divides C(S+F, S) without ever computing the huge binomial coefficient directly, using prime exponent analysis.	Hard8	Number theoryCombinatorics+2	No attempts yet	2s	128 MB	Judgeable
Paper FoldingGiven an N by M grid of integers, repeatedly fold it along row or column lines so overlapping cells sum, and find the maximum value obtainable in any cell.	Hard8	Dynamic programmingIntervals+2	No attempts yet	2s	128 MB	Judgeable
Zero Run PatternGiven two binary strings repeated in a growing pattern, find the first position within the first 10^16 characters where C consecutive zeros occur.	Hard8	StringBinary search+2	No attempts yet	2s	128 MB	Judgeable
IslandsGiven a grid of 8-connected islands and 4-connected seas, determine which islands enclose other islands and output island counts grouped by nesting height.	Hard8	BFSGraph+2	No attempts yet	2s	128 MB	Judgeable
FlippingGiven A zeros and B ones, find the minimum number of turns needed to flip exactly K chosen values each turn until all become 1, or -1 if impossible.	Hard8	BFSMath+2	No attempts yet	2s	128 MB	Judgeable
ShuffleCount song sequences (repeatable, with genre transition rules and per-song lengths 1 to 9) whose total play time lies in [A, B], modulo a prime.	Hard8	Dynamic programmingMatrix+2	No attempts yet	2s	128 MB	Judgeable
Floor DecorationGiven a rectangular window into an infinite 1x5 plank tiling pattern, find the minimum number of 1x5 boards needed to supply all the pieces inside it.	Hard8	MathImplementation+2	No attempts yet	2s	128 MB	Judgeable
Same TowersGiven up to 50 block heights summing to at most 500,000, find the maximum equal height achievable by two disjoint nonempty stacks, or report -1 if impossible.	Hard8	Dynamic programmingArray+1	No attempts yet	2s	512 MB	Judgeable
TteokgukPlace additional guards, subject to company office limits, so that the number of cooperation edges with exactly one guarded endpoint is minimized.	Hard8	GraphMinimum spanning tree+2	No attempts yet	2s	128 MB	Judgeable
Fibonacci KnapsackPick items whose weights are Fibonacci numbers into a bag of capacity C to maximize total value, where N is at most 50 and all numbers fit in 64 bits.	Hard8	Dynamic programmingGreedy+2	No attempts yet	2s	128 MB	Judgeable
Paper RacingFind the minimum number of turns for a car with adjustable integer velocity to reach the finish, where each turn changes each velocity component by at most 1 and the straight path must avoid obstacles until it hits the finish.	Hard8	BFSGraph+2	No attempts yet	2s	128 MB	Judgeable
Non-Repeating WordFind the lexicographically smallest length-N string over the first A letters that never contains K consecutive copies of any nonempty block.	Hard8	BacktrackingString+2	No attempts yet	2s	128 MB	Judgeable
Robot RaceGiven a grid with two robots and a shared command string, find the smallest starting position where robot Y is guaranteed to reach the target before robot F.	Hard8	BFSGraph+2	No attempts yet	2s	128 MB	Judgeable
Text Message FeesGiven a per-message fee and two reusable text-message packs with fixed price and quota, find the minimum cost to send exactly T messages.	Hard8	MathNumber theory+2	No attempts yet	2s	128 MB	Judgeable
Police StationsGiven costs and one-way roads among N villages, pick police-station villages so every village is reachable, minimizing the average station cost.	Hard8	GraphDFS+2	No attempts yet	2s	128 MB	Judgeable
Minimum Cost Connected CellsGiven an N by M grid of integers with N, M at most 9, find the minimum total cost over all connected sets of cells (empty set allowed).	Hard8	Dynamic programmingBit manipulation+2	No attempts yet	2s	128 MB	Judgeable
Picnic RhombiCount every rhombus whose four vertices sit on lattice points of an N by M grid of unit squares.	Hard8	CombinatoricsGeometry+2	No attempts yet	2s	128 MB	Judgeable
ShadowGiven a point light source and an axis-aligned box tree, compute the area of the shadow cast on the ground, handling infinite or zero-area degenerate cases.	Hard8	GeometryMath+1	No attempts yet	2s	128 MB	Judgeable
Toy SterilizationGiven daily toy demands over D days and two sterilization services with different delays and costs, decide which used toys to sterilize or discard versus buying new ones to minimize total cost.	Hard8	GreedyGraph+2	No attempts yet	2s	128 MB	Judgeable
BusGiven passenger groups each traveling between two bus stops, choose how many from each group to carry so total passengers are maximized without exceeding capacity C on any segment.	Hard8	GreedySegment tree+1	No attempts yet	2s	128 MB	Judgeable
Increasing ListReplace every '?' in a string with a digit or comma to form the lexicographically smallest strictly increasing list of positive integers with no leading zeros, or print -1 if impossible.	Hard8	BacktrackingGreedy+2	No attempts yet	2s	128 MB	Judgeable
CoveringTile every X cell of a grid using unrotated 6-cell A pieces and 2-cell horizontal B pieces without overlap, printing the lexicographically smallest covering or -1 if impossible.	Hard8	Dynamic programmingBacktracking+2	No attempts yet	2s	128 MB	Judgeable
Misheard BinaryCount distinct binary strings obtainable by shifting each bit of an N-bit number at most D positions, then output the K-th smallest such string.	Hard8	Dynamic programmingCombinatorics+2	No attempts yet	2s	128 MB	Judgeable
Returning to FarmingCount unordered pairs of non-empty axis-aligned rectangles on an N x N grid that touch at exactly one corner and have equal total cell profit.	Hard8	Prefix sumHash map+2	No attempts yet	1s	256 MB	Judgeable
Number Selection GameGiven 2N-1 integers where N is a power of two, select exactly N of them whose sum is divisible by N, using a doubling construction.	Hard8	Divide and conquerMath+2	No attempts yet	2s	128 MB	Judgeable
Chasing GameTwo players alternately move on a grid trying to reach the other's starting cell first, where landing on the opponent's cell grants a bonus move, and the task is to decide the winner under optimal play.	Hard8	Game theoryBFS+2	No attempts yet	2s	128 MB	Judgeable
GlovesGiven per-color counts of left and right gloves, find the pair (x, y) with minimum x+y (smallest x on ties) so that any draw of x left and y right gloves always yields a matching color pair.	Hard8	Bit manipulationGreedy+2	No attempts yet	2s	128 MB	Judgeable
Weather ForecastingChoose r horizontal and s vertical cut lines on an N x M grid to minimize the maximum sum of cell values inside any resulting rectangular section.	Hard8	Binary searchDynamic programming+2	No attempts yet	2s	128 MB	Judgeable
Coin Passing GameGiven biased left/right passing probabilities on a circle of N students starting at student K, compute the probability that student N is the last student to first receive the coin.	Hard8	ProbabilityDynamic programming+2	No attempts yet	2s	128 MB	Judgeable
Count Palindromic Word SequencesCount ordered sequences of given words, space-joined, whose concatenation (ignoring spaces) is a palindrome of length at most K, modulo a prime.	Hard8	Dynamic programmingString matching+2	No attempts yet	2s	128 MB	Judgeable
Make a Monotone SequenceGiven N nonnegative integers, build a monotone (non-decreasing or non-increasing) sequence minimizing the total absolute difference from the original.	Hard8	Dynamic programmingGreedy+2	No attempts yet	2s	128 MB	Judgeable
Boyle's LawCount positive integers N up to 10^18 whose self-product, N times the product of its digits, falls within a given range [A, B].	Hard8	MathDynamic programming+2	No attempts yet	2s	128 MB	Judgeable
Two-Bill PurchaseGiven a target amount D and two bill denominations P and Q, find the minimum total payment at least D achievable using nonnegative counts of each bill.	Hard8	Number theoryMath+2	No attempts yet	0.5s	128 MB	Judgeable
Fastest Grid RouteFind the minimum travel time between two grid intersections when rectangular districts change the per-block cost of roads inside them.	Hard8	Shortest pathGraph+2	No attempts yet	3s	512 MB	Judgeable
Closest PointsGiven up to 150,000 3D points, find the minimum squared distance between distinct points and count how many pairs achieve it, treating duplicate coordinates as one point.	Hard8	Divide and conquerGeometry+2	No attempts yet	1s	128 MB	Judgeable
Magic StoneGiven n, k, and i, find the i-th lexicographically smallest length-n I/X string with at most k differing adjacent pairs, treating a string and its reverse as identical.	Hard8	CombinatoricsDynamic programming+2	No attempts yet	2s	128 MB	Judgeable
FractionsGiven a fraction a/b and a bound c, find fractions a1/b1 <= a/b <= a2/b2 with denominators at most c that minimize a2/b2 - a1/b1.	Hard8	Number theoryMath+2	No attempts yet	2s	128 MB	Judgeable
Her HeartGiven up to 10000 obstacles on an infinite grid, count starting cells within S steps whose shortest obstacle-avoiding path to the origin has even or odd length.	Hard8	BFSMath+2	No attempts yet	2s	128 MB	Judgeable
Colored BallsSimulate repeatedly deleting the longest run of same-colored balls (leftmost on ties), merging neighbors after each removal, and report when the k-th original ball is deleted.	Hard8	HeapLinked list+2	No attempts yet	2s	128 MB	Judgeable
War - Declaration of WarGiven people's positions and speeds plus blocking line-segment obstacles, find the shortest obstacle-avoiding path to the border for each and output the maximum travel time.	Hard8	GeometryShortest path+2	No attempts yet	2s	128 MB	Judgeable
Rich Person's Coin ExchangeGiven a huge target amount M (up to 10^18) and up to 1000 coin denominations each at most 10000, find the minimum number of coins summing exactly to M.	Hard8	Shortest pathGraph+2	No attempts yet	2s	128 MB	Judgeable
P-SequencesCount permutations of a set of distinct integers where no two adjacent elements have a difference divisible by P, for two test cases, modulo 1234567891.	Hard8	CombinatoricsDynamic programming+1	No attempts yet	2s	256 MB	Judgeable
War - Local BattlesGiven colored points on a square battlefield, compute the total Voronoi cell area controlled by each of two countries.	Hard8	GeometryMath+1	No attempts yet	2s	128 MB	Judgeable
Floor PlanGiven an outer rectangle and inner rectangles drawn inside it, count the number of enclosed office regions and find the area of the largest one.	Hard8	Union-findGeometry+2	No attempts yet	2s	128 MB	Judgeable
Cave ExplorationFind the minimum total time to move all explorers across a bridge to the exit side, given one shared map, a weight-limited bridge, and trust rules for group crossings.	Hard8	Shortest pathBit manipulation+2	No attempts yet	2s	128 MB	Judgeable
Increasing SequenceSplit a digit string into pieces forming a strictly increasing sequence of numbers, minimizing the last value with tie-breaks favoring larger earlier numbers.	Hard8	Dynamic programmingString+2	No attempts yet	2s	128 MB	Judgeable
Parking LotAssign each of N cars to a distinct parking region on a grid with walls so the maximum travel time across all cars is minimized, or report impossibility.	Hard8	BFSBinary search+2	No attempts yet	1s	256 MB	Judgeable
Building FencesGiven N fence pieces on an infinite hexagonal grid, compute the maximum number of blocks (fence plus enclosed area) a single connected fence loop using all N pieces can occupy.	Hard8	GeometryMath+2	No attempts yet	2s	128 MB	Judgeable
War - Water Instead of FireFind the minimum water volume poured at a map corner so that, no matter how flow ties resolve, the enemy cell's water height reaches at least k.	Hard8	Binary searchHeap+2	No attempts yet	2s	128 MB	Judgeable
Merge WordsGiven up to 12 uppercase words, find the shortest string containing all of them as substrings, breaking ties by lexicographic order.	Hard8	Dynamic programmingBit manipulation+2	No attempts yet	5s	128 MB	Judgeable
Increasing SequenceSplit a huge digit string into pieces forming a strictly increasing sequence of numbers, breaking ties by minimizing the last piece then maximizing earlier pieces, and output the product mod 1,000,000,003.	Hard8	Dynamic programmingGreedy+2	No attempts yet	2s	128 MB	Judgeable
Kruskal's BallGiven a graph with unique edge weights, build a Kruskal reconstruction tree to answer queries about the minimum temperature needed to connect two vertices and the size of the reachable component at that temperature.	Hard8	Minimum spanning treeUnion-find+2	No attempts yet	2s	128 MB	Judgeable
This Looks Like an A-Level ProblemDecide whether integer A can be repeatedly factored into integers whose product stays A while some factorization's sum equals B, using transitive transformations.	Hard8	Number theoryMath+1	No attempts yet	2s	128 MB	Judgeable
Do Not Go to School!On a grid with walls, find the minimum number of empty cells to convert into walls so no path connects Dohyeon's cell to the school, using minimum vertex cut via max flow.	Hard8	GraphBFS+2	No attempts yet	2s	160 MB	Judgeable
Protective TentsGiven non-overlapping horizontal tents, add horizontal segments above them so that every point of the interval between the leftmost and rightmost endpoints receives downward water.	Hard8	GreedyIntervals+2	No attempts yet	2s	128 MB	Judgeable
Jinuk's FarmGiven up to 50 axis-aligned square paint operations over an N up to 1000 grid, find the largest square subregion containing no fruit type 0 and at most two distinct fruit types.	Hard8	Binary searchPrefix sum+1	No attempts yet	2s	128 MB	Judgeable
Quiz ShowFor N ordered quiz questions, choose right or wrong answers to maximize score: correct answers earn coins and points, hitting M coins gives a bonus, wrong answers reset coins and cost points.	Hard8	Dynamic programmingArray+2	No attempts yet	5s	128 MB	Judgeable
NetworkCount non-isomorphic trees on N+1 nodes where one fixed hub node has any degree but every other node must have odd degree.	Hard8	CombinatoricsTree+2	No attempts yet	2s	128 MB	Judgeable
Phone NumbersGreedily assign 7-digit hexadecimal phone numbers so any two differ in at least S positions, then output the K-th number picked this way.	Hard8	GreedyCombinatorics+2	No attempts yet	2s	128 MB	Judgeable
SquaresGiven up to 50 axis-aligned rectangles whose overlapping edges may form extra squares, count every square whose sides lie entirely on drawn line segments.	Hard8	GeometryPrefix sum+2	No attempts yet	2s	128 MB	Judgeable
Equal Digit CountsGiven N up to 10^18, find the smallest number at least N where every digit that appears occurs the same number of times.	Hard8	CombinatoricsBacktracking+2	No attempts yet	2s	128 MB	Judgeable
Minimum Resistor NetworkFind the minimum number of 1-ohm or 2-ohm resistors combined via series and parallel connections to achieve an exact resistance a/b, capped at 16 or else -1.	Hard8	MathRecursion+2	No attempts yet	2s	128 MB	Judgeable
Choosing GuitarsN guitars sit in a circle, and each turn the mover must take one guitar from every remaining contiguous group; find the max total value the first player can secure with optimal play.	Hard8	Dynamic programmingGame theory+2	No attempts yet	2s	128 MB	Judgeable
Nested Reversal SequenceGiven two binary strings, find the minimum number of substring reversals, each interval nested inside the previous one, needed to turn the first string into the second, or report impossibility.	Hard8	StringGreedy+2	No attempts yet	2s	128 MB	Judgeable
Isosceles TrianglesCount all isosceles triangles (non-collinear, at least two equal sides) formed by points in an N by M lattice grid, N and M up to 200.	Hard8	GeometryCombinatorics+2	No attempts yet	2s	128 MB	Judgeable
Increasing Arcade PathsCount monotone grid paths from (1,1) to (N,M) grouped by how many arcades they visit, valid only if visited arcade numbers strictly increase.	Hard8	Dynamic programmingCombinatorics+2	No attempts yet	2s	128 MB	Judgeable
Number ConcatenationGiven a subsequence left after deleting digits from the concatenation of 1,2,...,N, find the smallest N that could produce it.	Hard8	String matchingBinary search+2	No attempts yet	2s	128 MB	Judgeable
Random SortCompute the expected number of random inversion swaps needed to sort a permutation of size at most 8 into increasing order.	Hard8	ProbabilityDynamic programming+2	No attempts yet	2s	128 MB	Judgeable
Terminal CitiesGiven a connected graph with up to 15 cities, find a spanning tree that maximizes the number of vertices with degree exactly one.	Hard8	Dynamic programmingBit manipulation+2	No attempts yet	2s	128 MB	Judgeable
Lucky-number SumGiven N, express it as a sum of numbers made only of digits 4 and 7, using the fewest terms and, among ties, the lexicographically smallest sequence.	Hard8	Dynamic programmingGreedy+2	No attempts yet	2s	128 MB	Judgeable
Polygon Dissection CountGiven a convex N-gon, count the number of ways to cut it with non-crossing diagonals into exactly K polygons, modulo 1000000000, or report impossibility.	Hard8	CombinatoricsDynamic programming+1	No attempts yet	2s	128 MB	Judgeable
Dance, DanceFind the maximum number of rounds of perfect man-woman pairings, with no repeated pair and each person dancing with a disliked partner at most K times.	Hard8	GraphBinary search+2	No attempts yet	2s	128 MB	Judgeable
Expected Repaints for BallsGiven N colored balls, compute the expected number of random repaint operations needed until all balls share one color.	Hard8	ProbabilityDynamic programming+2	No attempts yet	2s	128 MB	Judgeable
Maximum Number of SquaresGiven N points on a plane, place them to maximize the number of axis-aligned squares whose four vertices are chosen points.	Hard8	MathCombinatorics+2	No attempts yet	2s	128 MB	Judgeable
Chess PracticeGiven N queens on a board, players alternately shift a queen toward (0,0) using Wythoff-move rules, and the winner is decided by XOR-ing Grundy values via Sprague-Grundy theory.	Hard8	Game theoryDynamic programming+1	No attempts yet	2s	128 MB	Judgeable
Tree PlantingCount sets of T collinear lattice points inside a W by H rectangle where every pair of points is at least distance D apart, modulo 1e9.	Hard8	CombinatoricsGeometry+2	No attempts yet	2s	128 MB	Judgeable
Domino Game 2Given an N x N matrix of back values, compute the sum over all permutations of the product of values times a sign based on cycle count, modulo 121547, which reduces to computing a determinant.	Hard8	MathMatrix+1	No attempts yet	2s	128 MB	Judgeable
Amazing MazeFind the minimum time to collect all treasures and reach the exit in a grid maze whose per-cell open door direction rotates clockwise every minute.	Hard8	BFSBit manipulation+2	No attempts yet	5s	512 MB	Judgeable
P-ArrayGiven an N by M integer matrix, find the minimum number of row/column sign flips so every row sum and column sum becomes positive, or report -1 if impossible.	Hard8	Bit manipulationBrute force+2	No attempts yet	1s	512 MB	Judgeable
Word RollingGiven N cyclic letter wheels rotating one step per second, find the earliest time t when all wheels simultaneously display a given target string, using CRT-style reasoning, or report -1.	Hard8	Number theoryMath+2	No attempts yet	2s	128 MB	Judgeable
LaserCount primitive direction vectors (a,b) with max(a,b) <= K whose periodic grid-wraparound character string contains each given word as a substring.	Hard8	Number theoryMath+2	No attempts yet	5s	128 MB	Judgeable
Binary Power BishopFind the minimum number of diagonal jumps, each by a distinct power of two, needed to move a bishop from (0,0) to a given point and output the visited cells.	Hard8	Bit manipulationMath+2	No attempts yet	2s	128 MB	Judgeable
Fugitive MonkeyGiven a graph with edge travel times and per-city delay values, answer many queries for the minimum path cost from S to T where cost equals edge sum plus the maximum node delay on the path.	Hard8	Union-findShortest path+2	No attempts yet	2s	128 MB	Judgeable
Monkey TowerCompute the minimum number of moves to solve a 4-peg Tower of Hanoi with up to one million disks, using the Frame-Stewart recurrence modulo 9901.	Hard8	Dynamic programmingMath+2	No attempts yet	2s	128 MB	Judgeable
Strategy Game TournamentGiven fixed win results between some pairs of N tournament players, determine every player who could still end up as champion.	Hard8	GraphUnion-find+2	No attempts yet	1s	256 MB	Judgeable
Rook AttacksPlace two rooks on an N x N grid so the total value of all cells attacked by either rook (excluding the rook cells) is maximized.	Hard8	MathPrefix sum+2	No attempts yet	2s	128 MB	Judgeable
Circle DanceGiven 2K+1 students, construct K circular seatings (Hamiltonian cycles) so every pair of students holds hands exactly once.	Hard8	CombinatoricsGraph+2	No attempts yet	2s	128 MB	Judgeable
Second Smallest Spanning TreeFind the minimum spanning tree, then compute the smallest spanning tree whose weight is strictly greater than the MST weight, or report -1 if none exists.	Hard8	Minimum spanning treeTree+2	No attempts yet	2s	128 MB	Judgeable
DuelTwo players alternately mark empty cells on a strip, winning instantly by forming three consecutive marks, and the task is to decide if the first player can force a win and list all winning first moves.	Hard8	Game theoryCombinatorics+2	No attempts yet	2s	128 MB	Judgeable
Minimum Pairing Cost for Two SetsGiven two sorted sets S and T, choose pairs (one element from each) so every element in both sets appears in some pair, minimizing the total sum of \|a-b\| over chosen pairs.	Hard8	Dynamic programmingGreedy+2	No attempts yet	2s	128 MB	Judgeable
Complete Binary TreeGiven two same-height complete binary trees whose leaves carry a permutation of labels, find the largest label subset whose pairwise leaf distances match in both trees.	Hard8	Dynamic programmingTree+2	No attempts yet	5s	128 MB	Judgeable
Lattice Convex PolygonGiven a rectangle of size M by N, find the maximum number of vertices a convex lattice polygon can have while staying inside it.	Hard8	GeometryDynamic programming+2	No attempts yet	2s	128 MB	Judgeable
TaxiCount directed paths from intersection A to B in a one-way road DAG that pass through a given set of required intermediate intersections in any order.	Hard8	GraphDynamic programming+2	No attempts yet	2s	256 MB	Judgeable
Jimin's Farm Tour Season IIFind two edge-disjoint paths from farm 1 to farm N and back that minimize total travel time using no road twice.	Hard8	GraphShortest path+1	No attempts yet	2s	128 MB	Judgeable
Two-Pan BalanceGiven distinct weights, count and rank all balance-point arrangements on a ten-mark two-pan scale as generated integers, returning the k-th smallest or the largest if fewer exist.	Hard8	BacktrackingCombinatorics+2	No attempts yet	1s	128 MB	Judgeable
Jang Hongjun the Tofu SellerGiven a grid of letter grades, tile it with non-overlapping 2x1 dominoes to maximize the sum of pairwise grade prices, leaving uncovered cells worth zero.	Hard8	GraphShortest path+2	No attempts yet	2s	128 MB	Judgeable
Pig CatchingGiven pig pens opened by daily keyed customers who buy up to a limit and pigs can be freely redistributed among opened pens, find the maximum total pigs sellable over all visits.	Hard8	Union-findGraph+1	No attempts yet	1s	256 MB	Judgeable
Minimum-Cost Number Matching (Hard)Given sorted sets S and T, choose pairs (s,t) with cost \|s-t\| so every element of both sets appears in at least one pair, minimizing total cost, for sizes up to 500000.	Hard8	Dynamic programmingGreedy+2	No attempts yet	2s	128 MB	Judgeable