Problems

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Total results29,068 problems

A guide for Seongjae traveling the multiverse
Hard9
Math, Divide and conquer+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
House Deconstruction
Hard9
Combinatorics, Greedy+1
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
MountainCraft
Hard9
Segment tree, Geometry+1
No attempts yet
Time limit
5s
Memory limit
2048 MB
Judgeable
Cheesology
Hard9
Graph, Shortest path+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Dormitory Parcel Delivery
Hard9
Dynamic programming, Divide and conquer+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Text Editor
Hard9
Shortest path, Greedy+1
No attempts yet
Time limit
4s
Memory limit
1024 MB
Judgeable
Grid Game
Hard9
Game theory, Bit manipulation+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Short Function
Hard9
Math, Number theory+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Four Color Theorem
Hard9
Graph, Implementation
No attempts yet
Time limit
4s
Memory limit
1024 MB
Judgeable
\prod_{i=1}^N(R_i-L_i+1) Trees
Hard9
Tree, Dynamic programming+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
On Forgetting
Hard9
Segment tree, Divide and conquer+1
No attempts yet
Time limit
4s
Memory limit
1024 MB
Judgeable
Escaping the Curse of Eungeung-i
Hard9
Probability, Game theory+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Manipulating the Torus Game
Hard9
Game theory, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
\mathbb{E}\left(\operatorname{LCS}\right)
Hard9
Probability, Combinatorics+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Tree
Hard9
Tree, Dynamic programming+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Jump
Hard9
Tree, Divide and conquer+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Infiltration
Hard9
Tree, Game theory+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
The Silk Road with Robots
Hard9
Segment tree, Greedy+1
No attempts yet
Time limit
5s
Memory limit
1024 MB
Judgeable
Make Them Meet
Hard9
Graph, Simulation+1
No attempts yet
Time limit
9s
Memory limit
1024 MB
Judgeable
Dynamic Cycle Queries
Hard9
Graph, Union-find+2
No attempts yet
Time limit
6s
Memory limit
1024 MB
Judgeable
Sums over a Power Sequence
Hard9
Number theory, Math+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Delayed Trains
Hard9
Segment tree, Intervals+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Hungry Arachnid
Hard9
Tree, DFS+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
LIS On Tree
Hard9
Tree, Dynamic programming+2
No attempts yet
Time limit
4s
Memory limit
1024 MB
Judgeable
Ladder Update
Hard9
Segment tree, Divide and conquer+2
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
River Crossing
Hard9
Graph, BFS+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Regular meeting 6
Hard9
Tree, Segment tree+1
No attempts yet
Time limit
5s
Memory limit
1024 MB
Judgeable
Tree Generators
Hard9
Tree, Dynamic programming+1
No attempts yet
Time limit
2s
Memory limit
2048 MB
Judgeable
Cactus Transformation
Hard9
Graph, Tree+2
No attempts yet
Time limit
3s
Memory limit
2048 MB
Judgeable
Great City Saint Petersburg
Hard9
Segment tree, Prefix sum+1
No attempts yet
Time limit
5s
Memory limit
2048 MB
Judgeable
Expected Beauty
Hard9
Dynamic programming, Probability+1
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Grid Game 3-angle
Hard9
Game theory, Math+1
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
X Aura
Hard9
Graph, Shortest path+1
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Collision
Hard9
Math, Number theory+1
No attempts yet
Time limit
9s
Memory limit
2048 MB
Judgeable
Electromagnetic Attacks
Hard9
Geometry, Graph+1
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Sweets
Hard9
Tree, Segment tree+1
No attempts yet
Time limit
3s
Memory limit
2048 MB
Judgeable
Big Data Permutation
Hard9
Segment tree, Array+1
No attempts yet
Time limit
15s
Memory limit
2048 MB
Judgeable
Grand Prix of Array Count
Hard9
Math, Number theory+1
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Don't Try This at Home
Hard9
Array, Combinatorics+1
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Mod Graph
Hard9
Graph, Number theory+2
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Divisible Trees
Hard9
Tree, Number theory+1
No attempts yet
Time limit
5s
Memory limit
2048 MB
Judgeable
Sum of Characteristics
Hard9
Divide and conquer, Math+1
No attempts yet
Time limit
4s
Memory limit
2048 MB
Judgeable
Hardcore String Counting
Hard9
String matching, Dynamic programming+1
No attempts yet
Time limit
8s
Memory limit
2048 MB
Judgeable
Dinosaur Bones Digging
Hard9
Segment tree, Sorting+1
No attempts yet
Time limit
5s
Memory limit
2048 MB
Judgeable
Lines
Hard9
Geometry, Sorting+1
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Too Many Edges
Hard9
Graph, Dynamic programming+1
No attempts yet
Time limit
15s
Memory limit
2048 MB
Judgeable
StrCartesian
Hard9
String, Trie+2
No attempts yet
Time limit
13s
Memory limit
2048 MB
Judgeable
Ald
Hard9
Tree, Divide and conquer+1
No attempts yet
Time limit
4s
Memory limit
2048 MB
Judgeable
01tree
Hard9
Tree, Dynamic programming+1
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Geometry Enjoyer
Hard9
Geometry, Math+1
No attempts yet
Time limit
7s
Memory limit
2048 MB
Judgeable
Trial of the Tile Master
Hard9
Math, Number theory+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Colored Slime Balls
Hard9
Dynamic programming, Intervals
No attempts yet
Time limit
2s
Memory limit
2048 MB
Judgeable
Yet Another Shortest Path Query
Hard9
Graph, Shortest path
No attempts yet
Time limit
12s
Memory limit
2048 MB
Judgeable
Top Cluster
Hard9
Divide and conquer, Tree+1
No attempts yet
Time limit
4s
Memory limit
2048 MB
Judgeable
Snake Move
Hard9
BFS, Graph+1
No attempts yet
Time limit
4s
Memory limit
2048 MB
Judgeable
Sugar Sweet II
Hard9
Probability, Dynamic programming+1
No attempts yet
Time limit
2s
Memory limit
2048 MB
Judgeable
Deep Abyss
Hard9
Bit manipulation, Implementation+1
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Apple Family Reunion
Hard9
Array, Math+1
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Wide Expression
Hard9
Math, Combinatorics+1
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Sum of a Sequence
Hard9
Math, Number theory+1
No attempts yet
Time limit
1.5s
Memory limit
1024 MB
Judgeable
Median Heap
Hard9
Tree, Dynamic programming+1
No attempts yet
Time limit
4s
Memory limit
2048 MB
Judgeable
f and g
Hard10
Math, Combinatorics+2
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Find Marble Positions and Velocities
Hard10
Math, Combinatorics+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Tree and Queries 20
Hard10
Tree, Segment tree+1
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Coalescing Continents
Hard10
Brute force, Math+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Cubes
Hard10
Combinatorics, Math+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Generator
Hard10
Implementation, String+2
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Logo
Hard10
Dynamic programming, Bit manipulation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
String Palindrome Queries
Hard10
String, String matching+1
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Suneung Fractions
Hard10
Math, Number theory+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Robots
Hard10
Implementation, Bit manipulation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Hyperrectangle
Hard10
Math, Divide and conquer+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Natural Park
Hard10
Graph, BFS+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Dungeon 2
Hard10
Graph, BFS+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Screamers in the Storm
Hard10
Geometry, Shortest path+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
The Creation
Hard10
Geometry, String matching+2
No attempts yet
Time limit
8s
Memory limit
1024 MB
Judgeable
Salty Fish
Hard10
Tree, Dynamic programming
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Dense Subgraph
Hard10
Tree, Binary search+2
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Shadow Companion
Hard10
Simulation, Bit manipulation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Delightful (Easy)
Hard10
Implementation, Simulation+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Link Cut Digraph
Hard10
Graph, Divide and conquer+1
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Joke
Hard10
Game theory, Simulation+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Comparing Plants
Hard10
Prefix sum, Segment tree+1
No attempts yet
Time limit
4s
Memory limit
1024 MB
Judgeable
Sail Shreds - 3
Hard10
Geometry, Greedy+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Xorshift64
Hard10
Math, Bit manipulation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Horses
Hard10
Graph, String+1
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
No Description 2
Hard10
Implementation
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
HQ0-9+-INCOMPUTABLE?!
Hard10
String, Simulation+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Beautiful Automata
Hard10
Graph, Topological sort+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Mysterious … Host
Hard10
Combinatorics, Math+2
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Grammy Sorting
Hard10
Graph, Simulation+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Fast Bridges
Hard10
Shortest path, Sorting+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Bananas
Hard10
Tree, Graph+1
No attempts yet
Time limit
8s
Memory limit
1024 MB
Judgeable
Huge Tree
Hard10
Game theory, Combinatorics+1
No attempts yet
Time limit
9s
Memory limit
1024 MB
Judgeable
Matrix nightmare
Hard10
Matrix, Combinatorics+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Good and Lucky Matrices
Hard10
Combinatorics, Math+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Magic Locks
Hard10
Matrix, Graph+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Joint Training
Hard10
Graph, Dynamic programming+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Cuckoos
Hard10
Graph, Union-find
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
ChatGPT's Masterpiece
Hard10
Implementation, Math+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable

Title	Level	Topics	Solved	Time limit	Memory limit	Judge
A guide for Seongjae traveling the multiverseGiven N points and a disk of radius R, find the mean over the disk of the product of squared distances from a random point to all N points, modulo 998244353.	Hard9	MathDivide and conquer+1	No attempts yet	3s	1024 MB	Judgeable
House DeconstructionGiven people and houses on a circle, find the minimum total walking distance after destroying some houses, and count the sets of destroyed houses that reach it.	Hard9	CombinatoricsGreedy+1	No attempts yet	1s	2048 MB	Judgeable
MountainCraftAfter each toggle of a mountain peak, the task is to print the total length of the visible skyline edges (the upper envelope of the triangles) within the viewport [0, w].	Hard9	Segment treeGeometry+1	No attempts yet	5s	2048 MB	Judgeable
CheesologyFind the max number of non-crossing down-right paths from top-left to bottom-right so every pair encloses some hole on opposite sides.	Hard9	GraphShortest path+1	No attempts yet	1s	1024 MB	Judgeable
Dormitory Parcel DeliveryFind the minimum time to start at the storage room, deliver every parcel, and return, when carried weight slows the walking speed to 1/(1+W).	Hard9	Dynamic programmingDivide and conquer+1	No attempts yet	1s	1024 MB	Judgeable
Text EditorGiven line lengths, find the fewest arrow key presses to move the cursor from a start position to a target, where up and down keep the column clamped to each line's end.	Hard9	Shortest pathGreedy+1	No attempts yet	4s	1024 MB	Judgeable
Grid GameTwo players alternate moving along right and down paths on a grid of XOR-modified values, and the task is to decide which player wins with optimal play.	Hard9	Game theoryBit manipulation+2	No attempts yet	2s	1024 MB	Judgeable
Short FunctionGiven array A of length N and K, find the final B after K rounds where round i sets B[j] to A[j] times A[(j+2i) mod N], modulo 998244353.	Hard9	MathNumber theory+2	No attempts yet	2s	1024 MB	Judgeable
Four Color TheoremGiven a planar graph and up to 6 forbidden color pairs, find a 4-coloring of the vertices that never puts a forbidden pair of colors on an edge, or print -1.	Hard9	GraphImplementation	No attempts yet	4s	1024 MB	Judgeable
\prod_{i=1}^N(R_i-L_i+1) TreesGiven a rooted tree with per-vertex caps and subtree sum lower bounds, sum the minimum weighted cost over all cost vectors in given ranges, modulo 998244353.	Hard9	TreeDynamic programming+2	No attempts yet	2s	1024 MB	Judgeable
On ForgettingGiven a sequence of swap operations that can be toggled on and off by index, answer queries for the element at a position in the current active set of swaps.	Hard9	Segment treeDivide and conquer+1	No attempts yet	4s	1024 MB	Judgeable
Escaping the Curse of Eungeung-iGiven N turns and M, find Hyeoncheol's optimal winning probability, where he wins if the overlaid polygons split the circle into an even number of pieces.	Hard9	ProbabilityGame theory+2	No attempts yet	2s	1024 MB	Judgeable
Manipulating the Torus GamePlayers alternately add edges to N tori without crossings; choose which tori to fill into spheres so the first player loses, or report impossible.	Hard9	Game theoryMath	No attempts yet	1s	1024 MB	Judgeable
\mathbb{E}\left(\operatorname{LCS}\right)Given N and M, find for each K from 1 to N the expected LCS length of M sequences built by random record draws from 1 to K, modulo 1e9+7.	Hard9	ProbabilityCombinatorics+1	No attempts yet	1s	1024 MB	Judgeable
TreeGiven a rooted weighted tree, find the minimum total of \|C[i]\| times W[i] so that every subtree coefficient sum lies between L and R.	Hard9	TreeDynamic programming+1	No attempts yet	2s	1024 MB	Judgeable
JumpGiven building heights, sum the minimum total squared-height-difference cost over all pairs of buildings that can reach each other by visible jumps, modulo 1000000007.	Hard9	TreeDivide and conquer+1	No attempts yet	2s	1024 MB	Judgeable
InfiltrationOutput a move schedule for two spies on a 100-room tree that minimizes the worst ratio of meeting time to starting distance.	Hard9	TreeGame theory+1	No attempts yet	1s	1024 MB	Judgeable
The Silk Road with RobotsAfter each day, report the maximum total profit from sending robots to stores, where a robot pays 1 tenge per meter moved and collects each store's tenges once.	Hard9	Segment treeGreedy+1	No attempts yet	5s	1024 MB	Judgeable
Make Them MeetGiven a connected graph of rooms, output lamp colour sequences so two walkers who move only to same-coloured neighbours are guaranteed to meet, whatever their starts.	Hard9	GraphSimulation+1	No attempts yet	9s	1024 MB	Judgeable
Dynamic Cycle QueriesMaintain an undirected multigraph under edge insertions and deletions, and answer whether two given edges lie on exactly the same simple cycles.	Hard9	GraphUnion-find+2	No attempts yet	6s	1024 MB	Judgeable
Sums over a Power SequenceGiven c and M, find for each m up to M the sum S(m) of all starting values a_1 where a_m + a_{m+1} = c+1, modulo 1000000007.	Hard9	Number theoryMath+1	No attempts yet	1s	1024 MB	Judgeable
Delayed TrainsGiven N delay reports that add D_i to the departure times of trains in ranges [L_i, R_i], count the red segments at each query moment T_i + 0.5 cho.	Hard9	Segment treeIntervals+1	No attempts yet	3s	1024 MB	Judgeable
Hungry ArachnidGiven a tree with spider legs on a, b, c and a fly on f, decide whether a leg can reach f through moves that keep the shadow size unchanged.	Hard9	TreeDFS+1	No attempts yet	1s	1024 MB	Judgeable
LIS On TreeGiven a tree where node x_i receives value i in order, report after each update the longest increasing subsequence over any path's nonblank values.	Hard9	TreeDynamic programming+2	No attempts yet	4s	1024 MB	Judgeable
Ladder UpdateGiven a ladder with legs, report after each add or delete query the fewest legs that produce the same final permutation.	Hard9	Segment treeDivide and conquer+2	No attempts yet	1s	2048 MB	Judgeable
River CrossingGiven N logs queried only by jump distance, the task is to output every pair of logs that can jump directly to each other within 30000 queries.	Hard9	GraphBFS+1	No attempts yet	2s	1024 MB	Judgeable
Regular meeting 6Count the vertices within distance d_i of home x_i for every resident i in each queried range l to r, on a tree with up to 1e9 vertices.	Hard9	TreeSegment tree+1	No attempts yet	5s	1024 MB	Judgeable
Tree GeneratorsGiven two expressions that build trees by joining subtrees with a random edge, count the distinct trees both expressions can generate, modulo 998244353.	Hard9	TreeDynamic programming+1	No attempts yet	2s	2048 MB	Judgeable
Cactus TransformationDecide whether one cactus graph can be turned into another by repeatedly removing an edge and adding a new one, at most 15000 times, and print the moves.	Hard9	GraphTree+2	No attempts yet	3s	2048 MB	Judgeable
Great City Saint PetersburgGiven street section heights, find the total trapped rain water before any updates and after each range increment that raises a segment by 1.	Hard9	Segment treePrefix sum+1	No attempts yet	5s	2048 MB	Judgeable
Expected BeautyEach A_i is uniform in [L_i, R_i]. Find the expected maximum score squared when deleting one of two adjacent equal elements adds its value to the score, mod 998244353.	Hard9	Dynamic programmingProbability+1	No attempts yet	1s	2048 MB	Judgeable
Grid Game 3-angleGiven stones on a triangular grid of up to 1e9 rows, decide whether the first player wins the game where each move removes up to K stones and adds up to K stones to cells below.	Hard9	Game theoryMath+1	No attempts yet	1s	2048 MB	Judgeable
X AuraGiven a grid of digit heights and an odd exponent X, answer queries for the minimum total penalty of moving between two cells, where each step costs (h1-h2)^X, or report INVALID if the cost can go unbounded below.	Hard9	GraphShortest path+1	No attempts yet	1s	2048 MB	Judgeable
CollisionGiven a roster of runners on a circular lake of length L, count how many pairs meet during T seconds after each add or remove query.	Hard9	MathNumber theory+1	No attempts yet	9s	2048 MB	Judgeable
Electromagnetic AttacksGiven a planar triangulation of base stations, decide for each axis-aligned rectangle whether the stations and links outside it stay connected.	Hard9	GeometryGraph+1	No attempts yet	1s	2048 MB	Judgeable
SweetsGiven a rooted tree where learning levels grow with each update, find for each day the most markets Sandu can pass on a root-to-k path.	Hard9	TreeSegment tree+1	No attempts yet	3s	2048 MB	Judgeable
Big Data PermutationGiven an array a and a permutation b, handle point updates to a and answer queries for the longest chain a[j+1]=b[a[j]] inside [l, r] that contains the value x.	Hard9	Segment treeArray+1	No attempts yet	15s	2048 MB	Judgeable
Grand Prix of Array CountCount arrays of length n with values from 1 to k where a[(i+j)/2] equals gcd(a[i], a[j]) for every pair with i+j even, modulo 1e9+7.	Hard9	MathNumber theory+1	No attempts yet	1s	2048 MB	Judgeable
Don't Try This at HomeFind the smallest k where applying f k times to array a flips some value between appearing once and at least twice, modulo 1e9+7, or -1.	Hard9	ArrayCombinatorics+1	No attempts yet	1s	2048 MB	Judgeable
Mod GraphGiven a connected graph where each vertex counter wraps modulo b_v on every visit, decide whether a walk from s can zero all counters, with point updates to counter values.	Hard9	GraphNumber theory+2	No attempts yet	1s	2048 MB	Judgeable
Divisible TreesGiven a tree T, count the distinct trees A such that T can be built from k copies of A joined by k-1 new edges.	Hard9	TreeNumber theory+1	No attempts yet	5s	2048 MB	Judgeable
Sum of CharacteristicsGiven a pseudorandom array of n integers, compute the sum over all subsegments of length at least 2 of the minimum over pairs i<j in the segment of max(a_i + j, a_j + i).	Hard9	Divide and conquerMath+1	No attempts yet	4s	2048 MB	Judgeable
Hardcore String CountingCount strings of length m over 26 letters where s first appears as a substring at the very end, modulo 998244353, with n up to 1e5 and m up to 1e9.	Hard9	String matchingDynamic programming+1	No attempts yet	8s	2048 MB	Judgeable
Dinosaur Bones DiggingFor each plan [l, r], the task is to pick a main sector m that maximizes a_m times the number of sectors in [l, r] deeper than a_m.	Hard9	Segment treeSorting+1	No attempts yet	5s	2048 MB	Judgeable
LinesGiven three arrays a, b, c, find every index i where line F_i is strictly above all other 3n lines at some real t, and print those indices.	Hard9	GeometrySorting+1	No attempts yet	1s	2048 MB	Judgeable
Too Many EdgesGiven a DAG G' that contains up to 200 extra edges beyond the original DAG G, find the longest path in G by querying which edges belong to G within a limited query budget.	Hard9	GraphDynamic programming+1	No attempts yet	15s	2048 MB	Judgeable
StrCartesianGiven string sets A and B, sort all concatenations a_i + b_j lexicographically and report the (i, j) pair at each queried position k.	Hard9	StringTrie+2	No attempts yet	13s	2048 MB	Judgeable
AldGiven a tree, maintain a multiset of paths under insertions and deletions and answer how many vertices lie within distance d of every path.	Hard9	TreeDivide and conquer+1	No attempts yet	4s	2048 MB	Judgeable
01treeGiven a tree of 0/1 node values with partial start and end states, sum the minimum flip counts over all consistent state pairs, modulo 1e9+7.	Hard9	TreeDynamic programming+1	No attempts yet	1s	2048 MB	Judgeable
Geometry EnjoyerGiven the pairwise intersection points of the extended sides of a convex polygon with no parallel sides, recover the polygon's vertices as exact rational coordinates.	Hard9	GeometryMath+1	No attempts yet	7s	2048 MB	Judgeable
Trial of the Tile MasterFor each timeline step, decide whether the accumulated flipped rectangles can be cleared back to all light-side-up using the row and column interval scrolls.	Hard9	MathNumber theory+1	No attempts yet	1s	512 MB	Judgeable
Colored Slime BallsFind the maximum net profit from selling every slime ball in a row, paying w per mass increase, where same-colored neighbors merge when the ball between them is sold.	Hard9	Dynamic programmingIntervals	No attempts yet	2s	2048 MB	Judgeable
Yet Another Shortest Path QueryGiven a weighted planar graph, answer queries for the shortest s-t path that uses at most three edges, or report -1 if no such path exists.	Hard9	GraphShortest path	No attempts yet	12s	2048 MB	Judgeable
Top ClusterGiven a weighted tree with distinct vertex values, answer queries by finding the smallest value not found within distance k of a given vertex x.	Hard9	Divide and conquerTree+1	No attempts yet	4s	2048 MB	Judgeable
Snake MoveGiven a grid with obstacles and a snake of length k, find the sum of squared minimum command counts for the head to reach each cell, modulo 2^64.	Hard9	BFSGraph+1	No attempts yet	4s	2048 MB	Judgeable
Sugar Sweet IIEach child gains w_i when event i fires with fewer sugar than child b_i, events in random order; output each child's expected final sugar mod 1e9+7.	Hard9	ProbabilityDynamic programming+1	No attempts yet	2s	2048 MB	Judgeable
Deep AbyssGiven a 128-bit hash function written as a short Frog program, find the smallest fixed point x with h(x) equal to x, or report that none exists.	Hard9	Bit manipulationImplementation+1	No attempts yet	1s	2048 MB	Judgeable
Apple Family ReunionGiven a permutation, find its family under the 123-transformation, then output the family size if its index is at most 65,472, or the index modulo 998244353 otherwise.	Hard9	ArrayMath+1	No attempts yet	1s	2048 MB	Judgeable
Wide ExpressionGiven n, m, k, l, compute the sum of (ab + cd + 1) raised to the power e XOR f over all a, b, c, d, e, f in the stated ranges, modulo 998244353.	Hard9	MathCombinatorics+1	No attempts yet	1s	2048 MB	Judgeable
Sum of a SequenceGiven N, S, and L, find the smallest X where 3^(X^3) matches the hash of all length-N sequences with entries 0 to L and sum S modulo 998244353, or print -1.	Hard9	MathNumber theory+1	No attempts yet	1.5s	1024 MB	Judgeable
Median HeapGiven a binary tree with node values and change costs, find the minimum cost to make the median-swap process output each query value m at the root.	Hard9	TreeDynamic programming+1	No attempts yet	4s	2048 MB	Judgeable
f and gCompute g(T,k)=sum_{x=0}^{T} sum_i (x+a_i)^k mod 1e9+7 for every k from 0 to K, given N up to 1e5, K up to 5e4, T up to 1e18.	Hard10	MathCombinatorics+2	No attempts yet	3s	512 MB	Judgeable
Find Marble Positions and VelocitiesReconstruct each marble's starting x-coordinate and constant velocity from N+1 unordered snapshots of N linearly moving marbles.	Hard10	MathCombinatorics+2	No attempts yet	2s	128 MB	Judgeable
Tree and Queries 20Maintain a dynamic forest with link/cut and weighted edges, supporting toggling a vertex weight and querying the minimum weighted sum of tree distances from any vertex, with encrypted vertex indices.	Hard10	TreeSegment tree+1	No attempts yet	5s	512 MB	Judgeable
Coalescing ContinentsGiven K rectangles with total area 25 on a 20x20 grid, decide if they can be translated to tile a square, and find the minimum total moves.	Hard10	Brute forceMath+2	No attempts yet	1s	128 MB	Judgeable
CubesCount the orbits of general-purpose chip placements on cube faces under face rotations and cube rearrangement, given a fixed pattern of encoding chips.	Hard10	CombinatoricsMath+2	No attempts yet	1s	128 MB	Judgeable
GeneratorRead an index 0 to 10 and output the exact contents of the matching recovered file gen_i.out from the archive.	Hard10	ImplementationString+2	No attempts yet	2s	256 MB	Judgeable
LogoGiven up to five polyomino patch shapes (each a subset of a 3x3 grid, flippable and rotatable) and up to three grid designs up to 55x5, decide if each design can be tiled exactly by non-overlapping patches and find the minimum patch count, or report NIE.	Hard10	Dynamic programmingBit manipulation+2	No attempts yet	1s	128 MB	Judgeable
String Palindrome QueriesMaintain a lowercase string under block moves, reversals, and single-character insertions, answering after each change whether a given substring reads the same forwards and backwards.	Hard10	StringString matching+1	No attempts yet	2s	256 MB	Judgeable
Suneung FractionsGiven x in [A,B] and y in [C,D] up to 1e12, count pairs where the reduced numerator and denominator sum to at most 999.	Hard10	MathNumber theory+2	No attempts yet	1s	1024 MB	Judgeable
RobotsDesign two robots' instruction tables so they classify a binary string as fine or coarse from its middle third's A and B counts, using four-bit memories, exact-then-wildcard dispatch, and 1000n steps.	Hard10	ImplementationBit manipulation+2	No attempts yet	2s	512 MB	Judgeable
HyperrectangleCompute d!V for the volume of a box with side lengths li where sum xi <= s via characteristic polynomials and Lenstra inclusion of capped orthants.	Hard10	MathDivide and conquer+2	No attempts yet	2s	512 MB	Judgeable
Natural ParkReconstruct the exact edge set of a sparse connected graph with degree at most 7 using at most 45,000 connectivity queries over chosen subsets.	Hard10	GraphBFS+2	No attempts yet	2s	512 MB	Judgeable
Dungeon 2Explore an unknown connected graph through a move-and-color oracle and report, for each i, how many room pairs have shortest-path distance exactly i.	Hard10	GraphBFS+2	No attempts yet	1s	256 MB	Judgeable
Screamers in the StormGiven a rectilinear roof polygon with two pigeon positions, compute the shortest walking-and-flying path length across the sloped roof surface.	Hard10	GeometryShortest path+1	No attempts yet	2s	512 MB	Judgeable
The CreationGiven N named points, weight Voronoi neighbor links by shared substring length, then answer minimum-path queries while parent links change.	Hard10	GeometryString matching+2	No attempts yet	8s	1024 MB	Judgeable
Salty FishPick which cameras to lock so that the apples on nodes seen only by locked cameras, minus the locking costs, is maximized.	Hard10	TreeDynamic programming	No attempts yet	3s	512 MB	Judgeable
Dense SubgraphCount vertex subsets L of a degree-at-most-5 tree whose beauty, the maximum density over connected subsets of size at least two, is at most x.	Hard10	TreeBinary search+2	No attempts yet	3s	512 MB	Judgeable
Shadow CompanionConstruct a fixed program over a bit tape with a shadow that transforms every input n < 2^10 into n squared.	Hard10	SimulationBit manipulation+2	No attempts yet	2s	512 MB	Judgeable
Delightful (Easy)Write a program of at most 100 commands for a ternary computer with 26 40-trit registers that computes the length of the longest non-decreasing prefix of the input in register X and leaves the answer in Y.	Hard10	ImplementationSimulation+2	No attempts yet	1s	512 MB	Judgeable
Link Cut DigraphEdges of a directed graph arrive one at a time, and after each insertion the task is to count pairs of vertices that are mutually reachable. Up to 1e5 vertices and 2.5e5 edges.	Hard10	GraphDivide and conquer+1	No attempts yet	3s	512 MB	Judgeable
JokeGiven both starting hands, the deck order, and the trump suit, decide which player wins the Fool's Game variant under optimal play, or whether it is a draw.	Hard10	Game theorySimulation+1	No attempts yet	2s	512 MB	Judgeable
Comparing PlantsGiven k and the counts r[i] of taller plants among the next k-1 plants in a circle, decide for each query pair whether one plant is always taller than the other.	Hard10	Prefix sumSegment tree+1	No attempts yet	4s	1024 MB	Judgeable
Sail Shreds - 3Given N triangles and a rectangle X by Y, place each triangle (translation only) so they tile the rectangle exactly with no overlaps.	Hard10	GeometryGreedy+1	No attempts yet	2s	512 MB	Judgeable
Xorshift64Given a start value x, find the 1-based index at which the target value t first appears in the xorshift64 sequence.	Hard10	MathBit manipulation+2	No attempts yet	2s	512 MB	Judgeable
HorsesGiven a commutation graph of horse kinds and a queue a, list the lexicographically ordered minimal queues b that commute with a, printing each as a polynomial hash modulo 998244353.	Hard10	GraphString+1	No attempts yet	2s	256 MB	Judgeable
No Description 2The statement gives no task, no input format, and no examples, so nothing about the required algorithm can be determined.	Hard10	Implementation	No attempts yet	2s	512 MB	Judgeable
HQ0-9+-INCOMPUTABLE?!Construct an HQ0-9+-INCOMPUTABLE?! program of at most 10000 commands whose final buffer equals a given target string.	Hard10	StringSimulation+2	No attempts yet	1s	1024 MB	Judgeable
Beautiful AutomataGiven a DAG, find the lexicographically smallest string whose suffix automaton is exactly this graph, or report -1 if none exists.	Hard10	GraphTopological sort+2	No attempts yet	2s	512 MB	Judgeable
Mysterious … HostFor each n up to N, find the minimum number of permutations needed so that every permutation of order n shares its answers to all consecutive-segment queries with one of them, modulo a prime P.	Hard10	CombinatoricsMath+2	No attempts yet	2s	256 MB	Judgeable
Grammy SortingGiven a connected graph with a permutation on vertices, use at most 10000 path rotations from A to make every vertex lie on a strictly increasing A-to-B path, or report -1.	Hard10	GraphSimulation+1	No attempts yet	1s	1024 MB	Judgeable
Fast BridgesGiven a k by k grid plus n bridges that cut travel time, find the sum of shortest distances over all cell pairs modulo 998244353.	Hard10	Shortest pathSorting+2	No attempts yet	2s	1024 MB	Judgeable
BananasAfter each update, report the town Bajtazar picks next, where each day he moves to the town maximizing profit minus the toll path from his current town.	Hard10	TreeGraph+1	No attempts yet	8s	1024 MB	Judgeable
Huge TreeGiven a layered tree and query layers for A, B, and their LCA, find the optimal final score difference of the painting game modulo 1e9+7 for each query.	Hard10	Game theoryCombinatorics+1	No attempts yet	9s	1024 MB	Judgeable
Matrix nightmareGiven a multivariate integer polynomial, construct a small matrix of integers and variables whose weighted traversal sum equals that polynomial, or report that none exists.	Hard10	MatrixCombinatorics+2	No attempts yet	1s	1024 MB	Judgeable
Good and Lucky MatricesGiven an n x n binary matrix of one type (good or lucky), map it injectively to a matrix of the other type so the mapping is a bijection.	Hard10	CombinatoricsMath+1	No attempts yet	2s	1024 MB	Judgeable
Magic LocksFor each grid of letters, find the maximum number of vertex-disjoint simple cycles inside same-letter cells and count the ways to achieve it, capped at 10^18.	Hard10	MatrixGraph+2	No attempts yet	2s	1024 MB	Judgeable
Joint TrainingGiven N units with bus costs and dissatisfaction updates, check each lineup's validity, find the max feasible session cost, and count distinct costs per unit.	Hard10	GraphDynamic programming+1	No attempts yet	3s	1024 MB	Judgeable
CuckoosEach nest holds at most one egg, so the eggs form a graph; answer whether an insertion terminates, add eggs when it does, and count the ordered pairs that terminate.	Hard10	GraphUnion-find	No attempts yet	2s	1024 MB	Judgeable
ChatGPT's MasterpieceGiven intervals [L[i], R[i]], find an x where f(x) is false and f(x+1) is true, with f defined by repeated exponentiation modulo 2^64.	Hard10	ImplementationMath+1	No attempts yet	1s	1024 MB	Judgeable