Problems

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Total results29,413 problems

Pizza Grows as You Slice It
Hard8
Math, Combinatorics+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Warm Pork Gukbap
Hard8
Dynamic programming, Binary search+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Two Tubes
Hard8
Greedy, Simulation+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Max or Min
Hard8
Implementation, Greedy+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Life Transfer
Hard8
Greedy, Sorting+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
3D Points and Queries
Hard8
Segment tree, Sorting+2
No attempts yet
Time limit
7s
Memory limit
1024 MB
Judgeable
Sequence and Queries 35
Hard8
Segment tree, Array+1
No attempts yet
Time limit
7s
Memory limit
512 MB
Judgeable
Game on a Tree
Hard8
Tree, Game theory+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Tree Permutations
Hard8
Greedy, Sorting+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Stranded Robot
Hard8
BFS, Implementation+1
No attempts yet
Time limit
4s
Memory limit
256 MB
Judgeable
Network Vulnerability
Hard8
Dynamic programming, Intervals+1
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Same Color
Hard8
Dynamic programming, Segment tree+1
No attempts yet
Time limit
0.5s
Memory limit
512 MB
Judgeable
Strike Zone
Hard8
Dynamic programming, Sorting+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Washer
Hard8
Geometry, Divide and conquer+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Drive Safely
Hard8
Dynamic programming, Geometry+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Equilibrium
Hard8
Tree, DFS+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Great GDP
Hard8
Binary search, Greedy+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Ice Cream
Hard8
Graph, Shortest path+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Computer Cache
Hard8
Segment tree, Array+2
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Fixed Point Permutations
Hard8
Combinatorics, Dynamic programming+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Interstellar Travel
Hard8
Geometry, Math+2
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Jumping Path
Hard8
Dynamic programming, DFS+2
No attempts yet
Time limit
10s
Memory limit
512 MB
Judgeable
Glow, Pixel, Glow!
Hard8
Sorting, Implementation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Harder Staircase Numbers
Hard8
Dynamic programming, Combinatorics+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Cocoa Coalition
Hard8
Dynamic programming, Greedy+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Algorithm Teaching
Hard8
Combinatorics, Bit manipulation+1
No attempts yet
Time limit
1.5s
Memory limit
512 MB
Judgeable
Building the Perfect House
Hard8
Geometry, Binary search+2
No attempts yet
Time limit
1.5s
Memory limit
512 MB
Judgeable
Cut Inequality Down
Hard8
Segment tree, Implementation+2
No attempts yet
Time limit
0.7s
Memory limit
512 MB
Judgeable
Dazzling Stars
Hard8
Geometry, Sorting+2
No attempts yet
Time limit
0.2s
Memory limit
512 MB
Judgeable
Hold or Continue?
Hard8
Dynamic programming, Probability+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Jumping Grasshopper
Hard8
Segment tree, Binary search+1
No attempts yet
Time limit
0.5s
Memory limit
512 MB
Judgeable
The Great Drone Show
Hard8
Union-find, Graph+1
No attempts yet
Time limit
30s
Memory limit
512 MB
Judgeable
Antennas
Hard8
Geometry, Sorting+1
No attempts yet
Time limit
8s
Memory limit
512 MB
Judgeable
Game of Falling Blocks
Hard8
Simulation, Greedy+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Golf Time
Hard8
Simulation, Math+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Disposable Switches
Hard8
Graph, Shortest path+1
No attempts yet
Time limit
4s
Memory limit
512 MB
Judgeable
Gnoll Hypothesis
Hard8
Probability, Dynamic programming+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Popcount
Hard8
Bit manipulation, Divide and conquer+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
ICPC
Hard8
Combinatorics, String matching+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Great Farmer Kim Sanghyuk
Hard8
Geometry, Math+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Miss Sloane
Hard8
Number theory, Greedy+1
No attempts yet
Time limit
5s
Memory limit
1024 MB
Judgeable
Optimal Selection
Hard8
Divide and conquer, Game theory+2
No attempts yet
Time limit
8s
Memory limit
1024 MB
Judgeable
Sequence and Queries 36
Hard8
Array, Sliding window+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Evaluation
Hard8
Implementation, Recursion+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Zeldain Garden
Hard8
Math, Number theory+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Light Emitting Hindenburg
Hard8
Bit manipulation, Greedy+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
K==S
Hard8
String matching, Dynamic programming+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
A Really Hard Problem
Hard8
Tree, DFS+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Candles and Shadows
Hard8
Geometry, Binary search+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Fraction Calculation
Hard8
Math, Sorting+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Dragon Ball II
Hard8
Graph, Shortest path+2
No attempts yet
Time limit
4s
Memory limit
512 MB
Judgeable
True/False Worksheet
Hard8
Dynamic programming, Prefix sum+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Twin Trees Bros.
Hard8
Tree, Geometry+1
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Ambiguous Encoding
Hard8
String matching, BFS+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Draw in Straight Lines
Hard8
Graph, Dynamic programming
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Sink the Billiard Ball
Hard8
Math, Number theory+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Who Has Not Read the Message?
Hard8
Combinatorics, Dynamic programming+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Water Tanks of Seongdae Country
Hard8
Tree, DFS+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Matrix Multiplication Order 2
Hard8
Dynamic programming, Greedy
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Shortest Paths and Queries
Hard8
Dynamic programming, Matrix+2
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Queries and Queries
Hard8
Segment tree, Bit manipulation+2
No attempts yet
Time limit
2.5s
Memory limit
1024 MB
Judgeable
Interleaved Periodic String
Hard8
Brute force, Dynamic programming+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Find The Number
Hard8
Math, Binary search+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Bessie's Snow Cow
Hard8
Tree, DFS+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Meetings
Hard8
Sorting, Math+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Grudanje
Hard8
Array, Binary search+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Close Numbers
Hard8
Array, Sorting+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Black Debt
Hard8
Segment tree, Binary search+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Dramatic Duel
Hard8
Game theory, Dynamic programming+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Fantastic Fožgaj
Hard8
Dynamic programming, String matching+2
No attempts yet
Time limit
1.5s
Memory limit
512 MB
Judgeable
Hero's Histogram
Hard8
Stack, Prefix sum+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Strong Jovsi
Hard8
String, Dynamic programming+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Coloring a Rectangle 2
Hard8
Dynamic programming, Matrix+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
NM and K (1)
Hard8
Dynamic programming, Bit manipulation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
NM and K (2)
Hard8
Dynamic programming, Bit manipulation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Bird Watching
Hard8
Graph, DFS+2
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Cave Paintings
Hard8
Graph, DFS+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Non-Decreasing Subsequences
Hard8
Dynamic programming, Divide and conquer+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Falling Portals
Hard8
Simulation, Sorting+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Farmer John Solves 3SUM
Hard8
Dynamic programming, Prefix sum+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Loan Repayment
Hard8
Binary search, Math+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Race
Hard8
Math, Greedy+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Cafebazaar's Chess Tournament
Hard8
Geometry, Sorting+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
The Big Surprise
Hard8
Geometry, Shortest path+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Let's Burn and Rob Manhootan
Hard8
Dynamic programming, Graph+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Gift Puzzle
Hard8
Geometry, Dynamic programming+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Start of the Pilgrimage
Hard8
Binary search, Greedy+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Perfect Pilgrimage
Hard8
Geometry, Math+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
The End of the Pilgrimage
Hard8
Probability, Dynamic programming+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Polynomial and Queries 2
Hard8
Math, Number theory+2
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Movie-goer
Hard8
Array, Two pointers+2
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Squares
Hard8
Dynamic programming, Math+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Seal
Hard8
Implementation, Simulation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Logistics
Hard8
Greedy, Sorting+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Visits
Hard8
Tree, Prefix sum+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Tree and Queries 14
Hard8
Tree, Divide and conquer
No attempts yet
Time limit
5s
Memory limit
1024 MB
Judgeable
Silver Mine
Hard8
Segment tree, Prefix sum+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
SUN Cactus Molecule
Hard8
Dynamic programming, Graph+2
No attempts yet
Time limit
5s
Memory limit
1024 MB
Judgeable
Copy Shop Scheduling
Hard8
Greedy, Sorting+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Strawberry
Hard8
Dynamic programming, Greedy+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable

Title	Level	Topics	Solved	Time limit	Memory limit	Judge
Pizza Grows as You Slice ItFor each K, choose the number of cuts that maximizes the pieces kept after giving away 1+2+...+k pieces to Yunhee.	Hard8	MathCombinatorics+1	No attempts yet	1s	256 MB	Judgeable
Warm Pork GukbapPlace any number of stores on a line of positions 1 to 50000, each store costs M, each delivery costs C times distance to nearest store; find the minimum total cost and the smallest number of stores achieving it.	Hard8	Dynamic programmingBinary search+2	No attempts yet	1s	256 MB	Judgeable
Two TubesArrange 2N apples in two open-ended tubes so that the sum of each size times its removal time is minimal, then print the minimum and one arrangement.	Hard8	GreedySimulation+1	No attempts yet	1s	256 MB	Judgeable
Max or MinGiven numbers on a circle and min/max operations over a value and its two neighbors, find for each x the least minutes to make all values equal x, or -1.	Hard8	ImplementationGreedy+2	No attempts yet	1s	256 MB	Judgeable
Life TransferGiven n ages, choose cars (k seats, driver at least lc) and motorcycles (driver at least lm) and transfer ages within limit d to minimize total rental and transfer cost.	Hard8	GreedySorting+2	No attempts yet	1s	256 MB	Judgeable
3D Points and QueriesCount points inside axis-aligned 3D boxes, where each query's box coordinates are decoded by XOR with the running sum of previous answers.	Hard8	Segment treeSorting+2	No attempts yet	7s	1024 MB	Judgeable
Sequence and Queries 35Given a permutation, each query rotates a subarray right by k positions, then asks whether the array has an increasing subsequence of length 3.	Hard8	Segment treeArray+1	No attempts yet	7s	512 MB	Judgeable
Game on a TreeAlice places a chip on a white node of a rooted tree, then players alternately move it to an unvisited ancestor or descendant, blackening that node; the player who cannot move loses. Determine the winner.	Hard8	TreeGame theory+2	No attempts yet	1s	256 MB	Judgeable
Tree PermutationsGiven a shuffled array of parent and weight values for a tree, find for each k the maximum weight sum on a path from vertex 1 to vertex n with exactly k edges.	Hard8	GreedySorting+1	No attempts yet	1s	256 MB	Judgeable
Stranded RobotFind the fewest moves for a robot on a 3D grid of ship blocks and vacuum to reach the teleporter, where each move depends on sunlight and gravity direction.	Hard8	BFSImplementation+1	No attempts yet	4s	256 MB	Judgeable
Network VulnerabilityGiven an interval representation of an interval graph, compute for each k the maximum number of connected components left after deleting exactly k vertices.	Hard8	Dynamic programmingIntervals+1	No attempts yet	3s	512 MB	Judgeable
Same ColorGiven n points on a line, each with one of m colors, find the smallest non-empty subset C so every other point's nearest point in C has its own color.	Hard8	Dynamic programmingSegment tree+1	No attempts yet	0.5s	512 MB	Judgeable
Strike ZoneGiven weighted point sets P1 (+c1 each) and P2 (-c2 each) with distinct x and y coordinates, find an axis-parallel rectangle maximizing c1s minus c2b.	Hard8	Dynamic programmingSorting+2	No attempts yet	1s	512 MB	Judgeable
WasherPartition up to 100 points in 3D into at most k groups (k <= 2) to minimize the sum of squared distances to each group's centroid.	Hard8	GeometryDivide and conquer+2	No attempts yet	1s	512 MB	Judgeable
Drive SafelyPlace k speed limit signs on a polyline road so that travel time is minimized, where each turn caps the speed limit by \|180 - alpha\| km/h.	Hard8	Dynamic programmingGeometry+2	No attempts yet	1s	512 MB	Judgeable
EquilibriumGiven a tree, order its vertices to minimize the sum over vertices of the absolute difference between neighbors placed after and before them.	Hard8	TreeDFS+2	No attempts yet	1s	512 MB	Judgeable
Great GDPGiven a vertex-weighted tree and a value and weight per node, find the connected subtree containing the root that maximizes total value divided by total weight.	Hard8	Binary searchGreedy+2	No attempts yet	1s	512 MB	Judgeable
Ice CreamGiven a capacitated pipe network with a chocolate source, a vanilla source, and a mixing sink, find the maximum flow that reaches the sink with equal chocolate and vanilla amounts.	Hard8	GraphShortest path+2	No attempts yet	1s	512 MB	Judgeable
Computer CacheMaintain a mutable byte array over m pieces, support range increments modulo 256 on a piece, cache loads of whole pieces into fixed cache positions, and point queries of cache bytes.	Hard8	Segment treeArray+2	No attempts yet	5s	512 MB	Judgeable
Fixed Point PermutationsFind the kth lexicographically smallest permutation of 1..n having exactly m fixed points, or print -1 if fewer than k exist.	Hard8	CombinatoricsDynamic programming+2	No attempts yet	1s	512 MB	Judgeable
Interstellar TravelGiven n angular intervals where each star contributes t - s*dist(a,b), find the launch angle b maximizing the sum of contributions.	Hard8	GeometryMath+2	No attempts yet	5s	512 MB	Judgeable
Jumping PathGiven a rooted tree with labels, find the length of the longest ancestor chain with nondecreasing labels, and count how many such chains of that length exist modulo 11092019.	Hard8	Dynamic programmingDFS+2	No attempts yet	10s	512 MB	Judgeable
Glow, Pixel, Glow!Given horizontal and vertical pulses crossing a grid of wires, count the pixels where current passes through both intersecting wires at the same time.	Hard8	SortingImplementation+2	No attempts yet	2s	512 MB	Judgeable
Harder Staircase NumbersCount the length-N B-ary staircase numbers (adjacent digits differ by 1, no leading zero) that use every digit from 0 to B-1, modulo M.	Hard8	Dynamic programmingCombinatorics+1	No attempts yet	2s	1024 MB	Judgeable
Cocoa CoalitionBreak an n by m chocolate bar with straight-line cuts into pieces that can be grouped into one pile of a cells and one of b cells, minimizing the number of cuts.	Hard8	Dynamic programmingGreedy+2	No attempts yet	1s	512 MB	Judgeable
Algorithm TeachingGiven teachers who each know up to 10 named algorithms, find the largest team of students whose training subsets are pairwise incomparable.	Hard8	CombinatoricsBit manipulation+1	No attempts yet	1.5s	512 MB	Judgeable
Building the Perfect HouseGiven N points, none at the origin, find the largest square centered at the origin that contains no point strictly inside it, then print its perimeter to four decimals.	Hard8	GeometryBinary search+2	No attempts yet	1.5s	512 MB	Judgeable
Cut Inequality DownFor many range queries [B,E] and starting wealth X, simulate monthly income with wealth clamped into [L,U] after each month and report the final wealth.	Hard8	Segment treeImplementation+2	No attempts yet	0.7s	512 MB	Judgeable
Dazzling StarsGiven N stars with coordinates and brightness, decide whether some rotation of the picture makes brighter stars print no later than dimmer ones, where printing goes top to bottom.	Hard8	GeometrySorting+2	No attempts yet	0.2s	512 MB	Judgeable
Hold or Continue?For each query state (Catelyn score, Hoster score, current turn total) decide hold or continue to maximize Catelyn's win probability when both play optimally in Pig to exactly 75.	Hard8	Dynamic programmingProbability+2	No attempts yet	2s	512 MB	Judgeable
Jumping GrasshopperHeights only increase over time, and for each sighting the task is to find the plant where a grasshopper that zigzags to the next taller plant finally stops.	Hard8	Segment treeBinary search+1	No attempts yet	0.5s	512 MB	Judgeable
The Great Drone ShowDrones rise and fall over k moves, and cables snap once stretched past their limit. For each queried pair, find the first move that disconnects them.	Hard8	Union-findGraph+1	No attempts yet	30s	512 MB	Judgeable
AntennasGiven a convex polygon with antennas inside, count the antenna pairs whose connecting line crosses neither of two removed walls, for each removal scenario.	Hard8	GeometrySorting+1	No attempts yet	8s	512 MB	Judgeable
Game of Falling BlocksSimulate a simplified Tetris game that uses bag randomization of the seven tetrominoes, and decide for each piece where to place it to complete at least one row before the game is lost.	Hard8	SimulationGreedy+2	No attempts yet	1s	512 MB	Judgeable
Golf TimeFor each start point, find when a diagonal ball bouncing off the course walls first hits the pond and where, or report that it never does.	Hard8	SimulationMath+1	No attempts yet	2s	512 MB	Judgeable
Disposable SwitchesFind the switches that never lie on an optimal path from switch 1 to switch n, whatever the cable speed and per-cable overhead turn out to be.	Hard8	GraphShortest path+1	No attempts yet	4s	512 MB	Judgeable
Gnoll HypothesisGiven n spawn probabilities and a random pool of k chosen types, compute each type's expected effective spawn chance after unchosen chances shift to the next chosen type cyclically.	Hard8	ProbabilityDynamic programming+2	No attempts yet	2s	512 MB	Judgeable
PopcountGiven N and K, produce a MalnarScript program of at most K commands that computes the popcount of an N-bit input using one variable.	Hard8	Bit manipulationDivide and conquer+2	No attempts yet	1s	512 MB	Judgeable
ICPCConcatenate all lowercase words of length 1 through N in length-then-alphabetical order; count occurrences of the substring "icpc" modulo 1e9+7, with N up to 1e9.	Hard8	CombinatoricsString matching+2	No attempts yet	2s	512 MB	Judgeable
Great Farmer Kim SanghyukChoose a radius r to maximize the daily profit from crops inside the circle (each worth wi times its distance to the boundary) minus the management cost A*r^2.	Hard8	GeometryMath+2	No attempts yet	2s	1024 MB	Judgeable
Miss SloaneChoose senators to lobby, dividing each chosen a_i by a divisor at most k, so that the gcd of all final values is greater than 1, minimizing the total lobbying time.	Hard8	Number theoryGreedy+1	No attempts yet	5s	1024 MB	Judgeable
Optimal SelectionGiven n <= 8 numbers and some known pairwise order relations, find the worst-case minimum number of comparisons an optimal comparison-based algorithm needs to output the k-th smallest.	Hard8	Divide and conquerGame theory+2	No attempts yet	8s	1024 MB	Judgeable
Sequence and Queries 36Given distinct values 1 to N, for each query [l, r] count the pairs x at most y inside it where max minus min equals y minus x.	Hard8	ArraySliding window+1	No attempts yet	1s	512 MB	Judgeable
EvaluationEvaluate an expression drawn as 2D ASCII art modulo 10^9+7, where the art encodes numbers, parentheses, fourth roots, operators, and fractions.	Hard8	ImplementationRecursion+1	No attempts yet	2s	512 MB	Judgeable
Zeldain GardenSum the number of divisors of every integer from N to M, where N and M can reach 10^12.	Hard8	MathNumber theory+2	No attempts yet	2s	512 MB	Judgeable
Light Emitting HindenburgChoose K of N bitmask schedules to maximize the bitwise AND of their codes, reading the result as the group availability code.	Hard8	Bit manipulationGreedy+2	No attempts yet	1s	512 MB	Judgeable
K==SCount sequences of length N over 26 letters that avoid any of Q given forbidden strings as contiguous substrings, modulo 1e9+7, where N can be up to 1e9.	Hard8	String matchingDynamic programming+2	No attempts yet	1s	512 MB	Judgeable
A Really Hard ProblemGiven a tree with colored vertices where same-colored vertices are never ancestor and descendant, find every vertex that can be the root and output their count, sum, and sum of squares.	Hard8	TreeDFS+1	No attempts yet	2s	512 MB	Judgeable
Candles and ShadowsGiven a convex red polygon that contains a convex blue polygon, find the shadow area cast by the blue polygon for each candle position.	Hard8	GeometryBinary search+1	No attempts yet	1s	512 MB	Judgeable
Fraction CalculationGiven N sorted fractions in [0, 1) read as points on a circle, decide whether some N-point sequence has a larger total pairwise circular distance.	Hard8	MathSorting+1	No attempts yet	1s	512 MB	Judgeable
Dragon Ball IIFind the minimum teleport cost from city 1 to collect Dragon Balls with seven pairwise distinct serial numbers, or report -1 if impossible.	Hard8	GraphShortest path+2	No attempts yet	4s	512 MB	Judgeable
True/False WorksheetCount binary strings of length n that satisfy range hints, where each hint says a range is all equal or not all equal, modulo 1e9+7.	Hard8	Dynamic programmingPrefix sum+2	No attempts yet	2s	512 MB	Judgeable
Twin Trees Bros.Given two 3D trees, count the node correspondences under which one tree maps onto the other by translation, uniform positive scaling, and axis rotations.	Hard8	TreeGeometry+1	No attempts yet	3s	512 MB	Judgeable
Ambiguous EncodingGiven a set of distinct binary codewords, decide whether two different character sequences can encode to the same bit string, and if so print the length of the shortest such string.	Hard8	String matchingBFS+2	No attempts yet	2s	512 MB	Judgeable
Draw in Straight LinesFind the minimum cost to paint a black-and-white grid using horizontal or vertical segments (cost a per pixel plus b) and single pixels (cost c).	Hard8	GraphDynamic programming	No attempts yet	3s	512 MB	Judgeable
Sink the Billiard BallA point ball bounces off the edges of an A by B table with velocity (p,q); count edge hits until it reaches a corner, or print -1 if it never stops.	Hard8	MathNumber theory+2	No attempts yet	1s	256 MB	Judgeable
Who Has Not Read the Message?Given each message's sender and the count of people who had not read it, count the possible sets of unread people per message, modulo 1e9+7.	Hard8	CombinatoricsDynamic programming+2	No attempts yet	1s	256 MB	Judgeable
Water Tanks of Seongdae CountryA tree of water tanks rooted at a capital. Adding water at city A adds 1,2,3,... along the root-to-A path. Answer queries about how much water a given city currently holds.	Hard8	TreeDFS+2	No attempts yet	1s	256 MB	Judgeable
Matrix Multiplication Order 2Given N matrix sizes in a fixed order, find the minimum number of scalar multiplications needed to compute their chain product.	Hard8	Dynamic programmingGreedy	No attempts yet	1s	512 MB	Judgeable
Shortest Paths and QueriesGiven a grid with up to 5 rows and 100,000 columns, answer queries for the minimum-weight monotone-free path between two cells.	Hard8	Dynamic programmingMatrix+2	No attempts yet	5s	512 MB	Judgeable
Queries and QueriesGiven an array and M range-XOR updates, answer queries that XOR a range of update values by v and queries that XOR a range of the final array.	Hard8	Segment treeBit manipulation+2	No attempts yet	2.5s	1024 MB	Judgeable
Interleaved Periodic StringGiven a binary string S, find the minimum total length of two binary strings whose repeated copies can be interleaved to produce S.	Hard8	Brute forceDynamic programming+2	No attempts yet	1s	512 MB	Judgeable
Find The NumberGiven up to 12 department numbers, find the n-th positive integer divisible by exactly one of them, with n up to 2^31.	Hard8	MathBinary search+2	No attempts yet	1s	512 MB	Judgeable
Bessie's Snow CowGiven a tree rooted at snowball 1, process subtree color-painting updates and report the sum of distinct colors per snowball over a queried subtree.	Hard8	TreeDFS+2	No attempts yet	2s	512 MB	Judgeable
MeetingsCows on a line swap velocities when they meet, stop at barns, and the question asks how many meetings occur before half the total weight has stopped.	Hard8	SortingMath+2	No attempts yet	1s	512 MB	Judgeable
GrudanjeGiven a word and Q substrings, find the first snowball throw index (in a given order of positions) after which no substring contains two uncovered equal letters.	Hard8	ArrayBinary search+2	No attempts yet	2s	512 MB	Judgeable
Close NumbersGiven a permutation p and q range queries [l, r], find the minimum absolute difference between any two values in the subarray p[l..r].	Hard8	ArraySorting+2	No attempts yet	2s	512 MB	Judgeable
Black DebtContestants get point increases over time; after each update, report the total count of (yellow, black) pairs where the black contestant has strictly more points.	Hard8	Segment treeBinary search+2	No attempts yet	1s	512 MB	Judgeable
Dramatic DuelGiven n carpet kinds and k stacked carpets, the task is to pick each carpet's orientation so the guide, who moves first, loses, or report that no such placement exists.	Hard8	Game theoryDynamic programming+1	No attempts yet	1s	512 MB	Judgeable
Fantastic FožgajCount length-m lowercase strings over 26 letters that avoid any of n forbidden patterns as a substring, modulo 1e9+7, with m up to 1e9.	Hard8	Dynamic programmingString matching+2	No attempts yet	1.5s	512 MB	Judgeable
Hero's HistogramGiven a histogram of n columns, for every prefix of the first j columns report the largest axis-aligned rectangle that fits inside that prefix.	Hard8	StackPrefix sum+2	No attempts yet	1s	512 MB	Judgeable
Strong JovsiCount the sequences of palindromic substrings (l1,r1) to (lk,rk) where l strictly increases and r strictly decreases, modulo 998244353.	Hard8	StringDynamic programming+1	No attempts yet	1s	512 MB	Judgeable
Coloring a Rectangle 2Count binary colorings of an N by M grid, N up to 1e18 and M at most 5, with no 2x2 block of a single color, modulo 1e9+7.	Hard8	Dynamic programmingMatrix+2	No attempts yet	1s	512 MB	Judgeable
NM and K (1)Choose exactly K non-adjacent cells from an N by M grid, at most 10 by 10, to maximize the sum of their values.	Hard8	Dynamic programmingBit manipulation+2	No attempts yet	2s	512 MB	Judgeable
NM and K (2)Choose exactly K non-adjacent cells from an N by M grid, each with a value, to maximize the total sum.	Hard8	Dynamic programmingBit manipulation+2	No attempts yet	2s	512 MB	Judgeable
Bird WatchingGiven a digraph P known to contain the true edge set G plus some path-shortcut edges, list all in-neighbors a of T such that every path from a to T uses the edge (a, T).	Hard8	GraphDFS+2	No attempts yet	3s	512 MB	Judgeable
Cave PaintingsCount modulo 1e9+7 the ways to fill empty cells of a bordered grid with water so that any lower-or-equal empty/water region reachable from a water cell is also water.	Hard8	GraphDFS+2	No attempts yet	2s	512 MB	Judgeable
Non-Decreasing SubsequencesGiven an array of values from 1 to K, answer queries counting non-decreasing subsequences within a subarray, including the empty one, modulo 1e9+7.	Hard8	Dynamic programmingDivide and conquer+2	No attempts yet	2s	512 MB	Judgeable
Falling PortalsEach world falls at speed i, and a cow can jump to another world when their portals align. Find each cow's earliest arrival time at its target world.	Hard8	SimulationSorting+1	No attempts yet	2s	512 MB	Judgeable
Farmer John Solves 3SUMCount, for each of Q queries, the number of unordered index triples in the subarray A[a..b] whose values sum to zero.	Hard8	Dynamic programmingPrefix sum+2	No attempts yet	2s	512 MB	Judgeable
Loan RepaymentFind the largest X so that paying floor((N-G)/X) milk per day, floored at M, clears N gallons within K days.	Hard8	Binary searchMath+2	No attempts yet	2s	512 MB	Judgeable
RaceGiven race length K and finish-speed cap X, find the minimum number of seconds for Bessie to cover at least K meters, with N queries.	Hard8	MathGreedy+2	No attempts yet	2s	512 MB	Judgeable
Cafebazaar's Chess TournamentGiven n players each with an opening and ending skill, count how many distinct tournament scores a new player with freely chosen distinct skills can achieve.	Hard8	GeometrySorting+2	No attempts yet	2s	512 MB	Judgeable
The Big SurpriseGiven up to 100 axis-aligned boxes, find the shortest rectilinear (Manhattan) 3D path between two points that avoids the boxes' interiors.	Hard8	GeometryShortest path+1	No attempts yet	2s	512 MB	Judgeable
Let's Burn and Rob ManhootanBob walks a monotone south-east path and back, and the blocks cut off from the border by the fire are his profit. Find the path that maximizes robbed value minus street costs on a grid up to 200 by 200.	Hard8	Dynamic programmingGraph+1	No attempts yet	2s	512 MB	Judgeable
Gift PuzzleGiven n horizontal rails with sliding obstacles on a board, find the shortest thread from the top-left to the bottom-right corner that avoids all obstacles.	Hard8	GeometryDynamic programming+1	No attempts yet	2s	512 MB	Judgeable
Start of the PilgrimageAfter each item is added, find the largest ratio of total divine power to total weight over any eight of the items collected so far.	Hard8	Binary searchGreedy+1	No attempts yet	3s	1024 MB	Judgeable
Perfect PilgrimageChoose N lattice points forming a counterclockwise polygon with no crossing edges and at least K equal sides, or report that no such choice exists.	Hard8	GeometryMath+1	No attempts yet	1s	1024 MB	Judgeable
The End of the PilgrimageGiven the last N visited sites, find the expected time until the last N visits are all distinct, printed modulo the prime X.	Hard8	ProbabilityDynamic programming+1	No attempts yet	1s	1024 MB	Judgeable
Polynomial and Queries 2Given a degree-N polynomial and K query points, evaluate the polynomial at every point modulo 1,030,307.	Hard8	MathNumber theory+2	No attempts yet	5s	512 MB	Judgeable
Movie-goerChoose a contiguous block of days maximizing the sum of weights of movies that appear exactly once in the block.	Hard8	ArrayTwo pointers+2	No attempts yet	5s	512 MB	Judgeable
SquaresGiven n up to 10^18, find the smallest possible largest base k(n) in a sum of distinct squares equal to n, and count the overgrown integers up to n.	Hard8	Dynamic programmingMath+1	No attempts yet	2s	512 MB	Judgeable
SealGiven a binary document grid and a binary seal stamp, decide whether the document is exactly the union of non-overlapping (and non-rotated) placements of the stamp.	Hard8	ImplementationSimulation+2	No attempts yet	2s	512 MB	Judgeable
LogisticsFor each query, decide whether c drivers who can each drive at most their own mileage limit can cover a route of s km in one convoy, given the drivers may swap at stops.	Hard8	GreedySorting+2	No attempts yet	2s	512 MB	Judgeable
VisitsGiven a tree, a visiting order, fuel prices, and tank capacities, compute the refueling cost of each trip in the order.	Hard8	TreePrefix sum+2	No attempts yet	2s	512 MB	Judgeable
Tree and Queries 14Given a tree with unit-weight edges, each query asks how many vertices lie within distance r_i of at least k-1 of the k given centers v_i.	Hard8	TreeDivide and conquer	No attempts yet	5s	1024 MB	Judgeable
Silver MineAfter each flip of a full row or column of an N by N grid, print the maximum mine count in a K by K window of lattice points and how many windows reach it.	Hard8	Segment treePrefix sum+1	No attempts yet	1s	1024 MB	Judgeable
SUN Cactus MoleculeGiven a cactus graph where each vertex has a cost for each of three colors, find the minimum cost of a proper coloring after each cost update.	Hard8	Dynamic programmingGraph+2	No attempts yet	5s	1024 MB	Judgeable
Copy Shop SchedulingGiven deadlines and page counts for orders arriving one by one, after each addition report the smallest possible maximum lateness when preemptive scheduling is allowed on one machine.	Hard8	GreedySorting+2	No attempts yet	2s	512 MB	Judgeable
StrawberryStrawberries at positions ripen at given times; starting and ending at 0, move at speed 1 and find the minimum time to harvest all after they ripen.	Hard8	Dynamic programmingGreedy+2	No attempts yet	2s	512 MB	Judgeable