Problems

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Total results29,384 problems

Sail Shreds 4
Hard8
Geometry, Greedy+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Sail Shreds - 6
Hard8
Geometry, Implementation+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Sail Shreds - 7
Hard8
Geometry, Greedy+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Sail Shreds - 8
Hard8
Geometry, Greedy+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Sail Shreds
Hard8
Geometry, Greedy+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Morning Sweet Potato
Hard8
Graph, Tree+2
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Sweet Potatoes for Breakfast
Hard8
Graph, Tree+2
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Squares and Cubes
Hard8
Math, Number theory+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Pipe Inspection
Hard8
Tree, String matching+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Old Book
Hard8
Math, Number theory+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
🎵I hate you, hate you, I hate you so much, don't come near me, stop pestering me🎵 - 2
Hard8
Sorting, Two pointers+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Radium Mining
Hard8
Array, Implementation+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Decryption
Hard8
Greedy, Stack+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Mineral Extraction
Hard8
Graph, Binary search
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Sorting Illusion
Hard8
Bit manipulation, Divide and conquer+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Journey to Metropolis
Hard8
Shortest path, Graph+1
No attempts yet
Time limit
4s
Memory limit
512 MB
Judgeable
Servers on Mercury
Hard8
Dynamic programming, Intervals+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Antimatter
Hard8
Dynamic programming, Sliding window
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Learning Trajectory
Hard8
Segment tree, Prefix sum+1
No attempts yet
Time limit
10s
Memory limit
512 MB
Judgeable
Bender
Hard8
Brute force, Implementation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Rollback
Hard8
Binary search, Prefix sum+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Sequence and Hunting
Hard8
Sorting, Greedy+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Kaisa - Survival
Hard8
Tree, DFS+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Vlak
Hard8
Trie, Game theory+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Specialization
Hard8
Tree, Implementation
No attempts yet
Time limit
4s
Memory limit
1024 MB
Judgeable
Strange Strings
Hard8
String, Hash map+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Holiday Train Trip
Hard8
Greedy, Segment tree+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
To Fish or Not to Fish
Hard8
Greedy, Sorting+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
CCTV Control
Hard8
Array, Implementation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Expected Distance
Hard8
Tree, Probability+1
No attempts yet
Time limit
4s
Memory limit
1024 MB
Judgeable
Dao and Dizzy's Date
Hard8
Dynamic programming, Math+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Complex Queries
Hard8
Graph, Bit manipulation+2
No attempts yet
Time limit
2.5s
Memory limit
1024 MB
Judgeable
Counting Stars
Hard8
Geometry, Divide and conquer+1
No attempts yet
Time limit
6s
Memory limit
1024 MB
Judgeable
Painting Pips
Hard8
Math, Dynamic programming+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Permutations on the Road: Bob
Hard8
Divide and conquer, Math+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Neural Networks
Hard8
Dynamic programming, Combinatorics+2
No attempts yet
Time limit
4s
Memory limit
1024 MB
Judgeable
Raid
Hard8
Dynamic programming, Divide and conquer+1
No attempts yet
Time limit
3s
Memory limit
768 MB
Judgeable
Broken line
Hard8
Greedy, Bit manipulation+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Territories
Hard8
Graph, Greedy
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Family photo
Hard8
Tree, Dynamic programming+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Abstract Circular Cover
Hard8
Dynamic programming, Intervals+1
No attempts yet
Time limit
20s
Memory limit
512 MB
Judgeable
Delete Two Vertices Again
Hard8
DFS, Graph+1
No attempts yet
Time limit
6s
Memory limit
512 MB
Judgeable
Game On Board
Hard8
Math, Combinatorics+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Hardcore String Counting 2
Hard8
String, Backtracking+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Inv
Hard8
Combinatorics, Dynamic programming+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Keep It Cool
Hard8
Dynamic programming, Bit manipulation
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
New Equipments
Hard8
Graph, Shortest path+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
The Missing Pet
Hard8
Probability, Matrix+1
No attempts yet
Time limit
4s
Memory limit
512 MB
Judgeable
In Search of Gold
Hard8
Tree, Dynamic programming+1
No attempts yet
Time limit
4s
Memory limit
512 MB
Judgeable
Walking Plan
Hard8
Graph, Shortest path+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Permutation
Hard8
Combinatorics, Dynamic programming+1
No attempts yet
Time limit
3s
Memory limit
256 MB
Judgeable
Distinct Number
Hard8
Bit manipulation, Intervals+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Partition Number
Hard8
Dynamic programming, Combinatorics+2
No attempts yet
Time limit
3s
Memory limit
256 MB
Judgeable
Stirling Number
Hard8
Number theory, Combinatorics+1
No attempts yet
Time limit
9s
Memory limit
256 MB
Judgeable
All your base are belong to us
Hard8
Geometry, Binary search+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Universal and Existential Quantifiers
Hard8
Greedy, Sorting+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Towns and Roads
Hard8
Tree, Shortest path+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Sleeping Cows
Hard8
Dynamic programming, Sorting+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Spaceship
Hard8
Dynamic programming, Graph+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Cowmistry
Hard8
Bit manipulation, Divide and conquer+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Lotte Giants and Gahui
Hard8
Math, Number theory+2
No attempts yet
Time limit
0.5s
Memory limit
512 MB
Judgeable
Just Buy Your Drinks, Please
Hard8
Binary search, Sorting+2
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Necklace Construction
Hard8
Dynamic programming, String+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
JJ Rally
Hard8
Shortest path, Dynamic programming+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
McFly
Hard8
Dynamic programming, Intervals+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
The Last Supper
Hard8
Simulation, Greedy
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Moon and Sun
Hard8
Math, Combinatorics+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Cul-De-Sac Parades
Hard8
Tree, DFS+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Shopping Changes
Hard8
Divide and conquer, Sorting+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Tasks for Indonesian Contests
Hard8
Graph, DFS+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Down We Dig
Hard8
Game theory, Dynamic programming+2
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Three Machines
Hard8
Math, Number theory+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Subway Map
Hard8
Minimum spanning tree, Union-find+2
No attempts yet
Time limit
4s
Memory limit
1024 MB
Judgeable
Cape and Gun
Hard8
Graph, Dynamic programming+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Ostap and chairs
Hard8
Geometry, Binary search+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Witch Dance
Hard8
Geometry, Sorting
No attempts yet
Time limit
5s
Memory limit
1024 MB
Judgeable
Combine The Gears
Hard8
Math, Number theory+2
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Arrange and Count!
Hard8
Combinatorics, Math+2
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Rikka with Game Theory
Hard8
Bit manipulation, Dynamic programming+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Ice Cream Game
Hard8
Game theory, Array+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
The Locksmith
Hard8
Math, Number theory+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Sequence and Queries 40
Hard8
String, Sorting+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Lamp Buttons
Hard8
Graph, Shortest path
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Disc World
Hard8
Shortest path, Graph+1
No attempts yet
Time limit
4s
Memory limit
1024 MB
Judgeable
Space Station Promenade
Hard8
Dynamic programming, Prefix sum+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Skidor
Hard8
Sliding window, Heap+2
No attempts yet
Time limit
7s
Memory limit
1024 MB
Judgeable
Christmas Shopping
Hard8
Dynamic programming, Bit manipulation+2
No attempts yet
Time limit
4s
Memory limit
1024 MB
Judgeable
Maze Construction
Hard8
Graph, String+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Decorative Dominoes
Hard8
Graph, DFS+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
XOR Data Structure
Hard8
Trie, Bit manipulation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
MapleStory
Hard8
Dynamic programming, Shortest path+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Space Stations
Hard8
Union-find, Geometry+2
No attempts yet
Time limit
2.5s
Memory limit
1024 MB
Judgeable
Divisor Ritual
Hard8
Bit manipulation, Dynamic programming+2
No attempts yet
Time limit
1.75s
Memory limit
1024 MB
Judgeable
Maskpunk 2077
Hard8
Segment tree, Binary search+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
The Formula Sicheol Loved
Hard8
Number theory, Math+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
KakaoTalk
Hard8
Geometry, Hash map+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Chair Game
Hard8
Array, Number theory+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Telephone Network Service with Go
Hard8
Graph, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Game Developer Seunghee
Hard8
Math, Number theory+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Magenta
Hard8
Game theory, Tree+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable

Title	Level	Topics	Solved	Time limit	Memory limit	Judge
Sail Shreds 4Translate each triangle without rotation so that the triangles exactly tile an X by Y rectangle, with no overlaps and no part outside.	Hard8	GeometryGreedy+1	No attempts yet	2s	512 MB	Judgeable
Sail Shreds - 6Place N triangles into an X by Y rectangle without rotating them so they tile it exactly, then output the new position of each triangle's vertex A.	Hard8	GeometryImplementation+1	No attempts yet	2s	512 MB	Judgeable
Sail Shreds - 7Place N triangles on an X by Y rectangle without rotating them so they tile it with no overlaps, then print the new position of vertex A for each triangle.	Hard8	GeometryGreedy+1	No attempts yet	2s	512 MB	Judgeable
Sail Shreds - 8Translate each triangular shred without rotation so that the shreds tile the X by Y rectangle exactly, with no overlaps and nothing outside the sail.	Hard8	GeometryGreedy+1	No attempts yet	2s	512 MB	Judgeable
Sail ShredsTranslate each triangle without rotation so that the shreds tile an X by Y rectangle exactly, with no overlaps and nothing outside the rectangle.	Hard8	GeometryGreedy+1	No attempts yet	2s	512 MB	Judgeable
Morning Sweet PotatoGiven a cactus-like graph with root 1, find the maximum total squared length of tuber cycles that stay pulled out under a minimum-strength cut to the root tips.	Hard8	GraphTree+2	No attempts yet	3s	512 MB	Judgeable
Sweet Potatoes for BreakfastGiven a graph of trees and cycles rooted at vertex 1, sum the squared cycle sizes kept on the root side of a minimum-cost cut that separates the root from the root tips.	Hard8	GraphTree+2	No attempts yet	3s	512 MB	Judgeable
Squares and CubesCount pairs of natural numbers x, y with a <= x^2 <= b, a <= y^3 <= b, and \|x^2 - y^3\| <= k, for a, b, k up to 10^18.	Hard8	MathNumber theory+2	No attempts yet	1s	512 MB	Judgeable
Pipe InspectionCover every edge of a rooted pipe tree with downward walks that spell given letter patterns, at the minimum total pattern cost.	Hard8	TreeString matching+1	No attempts yet	1s	512 MB	Judgeable
Old BookGiven that the first k pages are illustrations and the page numbers on text pages sum to s, find the minimum possible number of illustrations in the book.	Hard8	MathNumber theory+2	No attempts yet	1s	512 MB	Judgeable
🎵I hate you, hate you, I hate you so much, don't come near me, stop pestering me🎵 - 2Given K non-overlapping axis-aligned rectangles (holes) and a square of side L, find the maximum number of rectangles fully covered by some placement of the square.	Hard8	SortingTwo pointers+2	No attempts yet	1s	1024 MB	Judgeable
Radium MiningGiven a grid of distinct values, count cells that are the maximum in both their row and column after each update that only increases a cell's value.	Hard8	ArrayImplementation+2	No attempts yet	1s	512 MB	Judgeable
DecryptionSplit the sequence into the fewest non-overlapping segments where each segment's first element is its minimum and last element is its maximum.	Hard8	GreedyStack+2	No attempts yet	1s	512 MB	Judgeable
Mineral ExtractionFind the largest number of leading batches, and then the most robots from the next batch, that can be placed on the grid with at most q robots per cell.	Hard8	GraphBinary search	No attempts yet	3s	512 MB	Judgeable
Sorting IllusionFind the smallest b making a[i] xor b nondecreasing, updating the answer after each of q point changes to the array.	Hard8	Bit manipulationDivide and conquer+2	No attempts yet	2s	512 MB	Judgeable
Journey to MetropolisFind the minimum total train time from city 1 to city n, and the largest sum of squared ride lengths among trips that reach that minimum.	Hard8	Shortest pathGraph+1	No attempts yet	4s	512 MB	Judgeable
Servers on MercuryFor each server on a path, find the earliest time to send the package there so it reaches all n servers, given edge time windows and buffer durations.	Hard8	Dynamic programmingIntervals+1	No attempts yet	2s	512 MB	Judgeable
AntimatterGiven experiment types that add an amount in a range at a cost, find the largest profit that can be guaranteed while the container never exceeds a grams.	Hard8	Dynamic programmingSliding window	No attempts yet	2s	128 MB	Judgeable
Learning TrajectoryChoose one contiguous range of courses at each university so that no course ID appears in both plans, maximizing the total rating.	Hard8	Segment treePrefix sum+1	No attempts yet	10s	512 MB	Judgeable
BenderChoose parameters a, b, c of a linear congruential sequence so that n swaps of adjacent cups move the ball from position r to position l, or report Impossible.	Hard8	Brute forceImplementation+2	No attempts yet	2s	512 MB	Judgeable
RollbackFor each online query (l, k), find the smallest r such that the subarray a[l..r] contains at least k distinct server numbers, or report 0 if impossible.	Hard8	Binary searchPrefix sum+2	No attempts yet	2s	512 MB	Judgeable
Sequence and HuntingEach of N intervals [ai-bi, ai+bi] can be realized by any real value; for each interval report the smallest and largest 1-based rank it can take after sorting the chosen values.	Hard8	SortingGreedy+2	No attempts yet	1s	1024 MB	Judgeable
Kaisa - SurvivalGiven a rooted tree, take the LCA of every ordered pair of vertices (including x=y), collect all N^2 results into one multiset, sort it, then print the sum of values at odd and even positions.	Hard8	TreeDFS+2	No attempts yet	1s	1024 MB	Judgeable
VlakTwo players alternately append letters so the growing word stays a prefix of a word in the mover's own song; decide who wins under optimal play.	Hard8	TrieGame theory+2	No attempts yet	1s	512 MB	Judgeable
SpecializationGiven a layered tree where one vertex per level has two children, answer online queries for the largest common ancestor of two labeled vertices.	Hard8	TreeImplementation	No attempts yet	4s	1024 MB	Judgeable
Strange StringsGiven a string s, count the number of distinct substrings t such that the set of substrings of t equals the set of subsequences of t.	Hard8	StringHash map+2	No attempts yet	1s	512 MB	Judgeable
Holiday Train TripFor each trip, find the fewest new tickets needed to cover every segment with seat changes allowed, or -1 if the trip is impossible.	Hard8	GreedySegment tree+1	No attempts yet	2s	512 MB	Judgeable
To Fish or Not to FishChoose fishing points to visit and bases to sell at along a river, paying fuel only while moving upstream, to maximize profit.	Hard8	GreedySorting+2	No attempts yet	1s	512 MB	Judgeable
CCTV ControlGiven an n by m grid of 1s and 2s that can be cyclically shifted in rows and columns, maximize the number of 2x2 blocks whose four cells all match.	Hard8	ArrayImplementation+2	No attempts yet	2s	512 MB	Judgeable
Expected DistanceEach vertex attaches to an earlier vertex with probability proportional to a_j. For each query (u, v), output the expected distance between them modulo 1e9+7.	Hard8	TreeProbability+1	No attempts yet	4s	1024 MB	Judgeable
Dao and Dizzy's DateWalk on a line of N places for T minutes starting and ending at place 1, gaining h[j] whenever you move to place j, and maximize total happiness.	Hard8	Dynamic programmingMath+2	No attempts yet	1s	1024 MB	Judgeable
Complex QueriesGiven a connected weighted undirected graph, define d(u,v) as the maximum XOR weight of any walk from u to v; answer queries asking for the XOR of d(i,j) over all pairs l<=i<j<=r.	Hard8	GraphBit manipulation+2	No attempts yet	2.5s	1024 MB	Judgeable
Counting StarsStars are added over time with beauty values, and each query asks for the total beauty of the stars on or inside the triangle formed by three given stars.	Hard8	GeometryDivide and conquer+1	No attempts yet	6s	1024 MB	Judgeable
Painting PipsGiven N dice and M total pips to distribute across faces, find the maximum expected product of the rolled values.	Hard8	MathDynamic programming+2	No attempts yet	1s	1024 MB	Judgeable
Permutations on the Road: BobGiven up to N queries returning the inversion count within a subarray, reconstruct the hidden permutation of length N.	Hard8	Divide and conquerMath+2	No attempts yet	2s	1024 MB	Judgeable
Neural NetworksCount labeled layered digraphs in which every node lies on some directed path from layer 1 to layer N, modulo 998244353.	Hard8	Dynamic programmingCombinatorics+2	No attempts yet	4s	1024 MB	Judgeable
RaidFor each k from 1 to n, pick k soldiers from a permutation so the number of inversions among them is minimal, then report that minimum and how many selections reach it.	Hard8	Dynamic programmingDivide and conquer+1	No attempts yet	3s	768 MB	Judgeable
Broken lineAssign each of the up to 16 distinct letters a fixed arrow (right or up) so the area under the resulting monotone staircase path is maximized.	Hard8	GreedyBit manipulation+2	No attempts yet	1s	512 MB	Judgeable
TerritoriesPlace all animals in grid cells outside each species' forbidden rectangle to maximize the number of pairs that share a cell.	Hard8	GraphGreedy	No attempts yet	1s	512 MB	Judgeable
Family photoGiven a rooted family tree, find the largest set of members that can stand in a row so that every two neighbors are an ancestor and a descendant.	Hard8	TreeDynamic programming+1	No attempts yet	2s	512 MB	Judgeable
Abstract Circular CoverGiven costs c[i][l] for arcs of length l starting at point i, find for each k the minimum total cost of k arcs that partition the n points on a circle.	Hard8	Dynamic programmingIntervals+1	No attempts yet	20s	512 MB	Judgeable
Delete Two Vertices AgainFor each edge of a connected graph, decide whether deleting both of its endpoints leaves the remaining graph connected, and print a binary string.	Hard8	DFSGraph+1	No attempts yet	6s	512 MB	Judgeable
Game On BoardCount the minimal initial boards (with the fewest black cells) on an n by m grid from which the closure rule paints every cell black, modulo 998244353.	Hard8	MathCombinatorics+2	No attempts yet	2s	512 MB	Judgeable
Hardcore String Counting 2Count the square-free words of each length from 1 to n over the alphabet {a, b, c}, where n is at most 120.	Hard8	StringBacktracking+1	No attempts yet	2s	512 MB	Judgeable
InvCount involutions of n elements with exactly k inversions and report the count modulo 2.	Hard8	CombinatoricsDynamic programming+2	No attempts yet	2s	512 MB	Judgeable
Keep It CoolCount permutations of all pairs (a, b) with a < b that satisfy the betweenness rule for every triple and m given order constraints, modulo 998244353.	Hard8	Dynamic programmingBit manipulation	No attempts yet	1s	512 MB	Judgeable
New EquipmentsAssign workers to equipment, where worker i pays a_ij^2+b_ij+c_i on machine j, and report the minimum total cost for each k from 1 to n.	Hard8	GraphShortest path+1	No attempts yet	2s	512 MB	Judgeable
The Missing PetFor each hole on an n by n board, find the expected steps of a random walk from a start cell, given it falls into that hole, modulo 10^9+7.	Hard8	ProbabilityMatrix+1	No attempts yet	4s	512 MB	Judgeable
In Search of GoldGiven a tree where each edge has two candidate lengths and exactly k edges take the first length, find the minimum possible diameter.	Hard8	TreeDynamic programming+1	No attempts yet	4s	512 MB	Judgeable
Walking PlanFor each query, find the minimum total length of a walk from s to t that uses at least k edges in a directed weighted graph.	Hard8	GraphShortest path+2	No attempts yet	2s	512 MB	Judgeable
PermutationCount the ways to fill the unknown positions of a partial permutation so the result has an arithmetic progression subsequence of length 3 or more, modulo 10^9+7.	Hard8	CombinatoricsDynamic programming+1	No attempts yet	3s	256 MB	Judgeable
Distinct NumberGiven x and n intervals, count how many distinct values of i AND x occur for integers i in the union of the intervals.	Hard8	Bit manipulationIntervals+1	No attempts yet	1s	512 MB	Judgeable
Partition NumberCount partitions of m into nondecreasing positive parts, where a given set of n values is forbidden as a part, modulo 1e9+7.	Hard8	Dynamic programmingCombinatorics+2	No attempts yet	3s	256 MB	Judgeable
Stirling NumberGiven n, l, r, and a prime p, compute the sum of unsigned Stirling numbers of the first kind [n, k] for k from l to r, modulo p.	Hard8	Number theoryCombinatorics+1	No attempts yet	9s	256 MB	Judgeable
All your base are belong to usChoose any point in the plane to minimize the sum of distances to the K farthest bases, and output that minimum sum.	Hard8	GeometryBinary search+2	No attempts yet	2s	512 MB	Judgeable
Universal and Existential QuantifiersGiven N half-open intervals whose union is [0,L), find the fewest intervals whose union is [0,L) and the fewest k such that any k intervals already cover [0,L).	Hard8	GreedySorting+2	No attempts yet	2s	512 MB	Judgeable
Towns and RoadsGiven a tree of towns, handle road closures, reopenings, and robot moves, then list all towns farthest from the robot among open roads.	Hard8	TreeShortest path+2	No attempts yet	2s	512 MB	Judgeable
Sleeping CowsCount the maximal matchings between cows and barns, where each cow fits in its assigned barn and no unmatched cow fits in any empty barn, modulo 1e9+7.	Hard8	Dynamic programmingSorting+1	No attempts yet	1s	512 MB	Judgeable
SpaceshipCount the valid sequences of room moves and button presses that get Bessie from room s with button b_s to room t ending on button b_t, modulo 1e9+7, for each query.	Hard8	Dynamic programmingGraph+1	No attempts yet	1s	512 MB	Judgeable
CowmistryCount the sets of three distinct labels, taken from N disjoint integer intervals, where every pair has XOR at most K, modulo 1e9+7.	Hard8	Bit manipulationDivide and conquer+1	No attempts yet	1s	512 MB	Judgeable
Lotte Giants and GahuiCount length-n sequences of positive integers whose gcd is G and lcm is L, printing each answer modulo 1e9+7.	Hard8	MathNumber theory+2	No attempts yet	0.5s	512 MB	Judgeable
Just Buy Your Drinks, PleaseEach query asks for the highest taste threshold t such that liquids with d_i >= t can supply at least L liters within budget g, respecting per-liquid caps.	Hard8	Binary searchSorting+2	No attempts yet	3s	1024 MB	Judgeable
Necklace ConstructionGiven a target string of up to 300 lowercase letters, find the minimum number of edit and copy-reverse operations to build it from an empty buffer necklace.	Hard8	Dynamic programmingString+2	No attempts yet	2s	512 MB	Judgeable
JJ RallyCount the pairs of vertex-disjoint shortest paths, one from s1 to t1 and one from s2 to t2, in a weighted graph with up to 24 intersections.	Hard8	Shortest pathDynamic programming+1	No attempts yet	2s	512 MB	Judgeable
McFlyGiven cookies at fixed positions, each available during its own time window, find the most tastes McFly can make while moving at 1 meter per second.	Hard8	Dynamic programmingIntervals+1	No attempts yet	2s	512 MB	Judgeable
The Last SupperGiven n guests seated in a circle, m initially infected guests, and q timed talks between neighbors, list every guest who could be the source that infects all sick guests.	Hard8	SimulationGreedy	No attempts yet	2s	512 MB	Judgeable
Moon and SunCount indices i where changing A_i to some other integer in [-100000, 100000] makes the single element of the N-fold difference sequence a multiple of 235813.	Hard8	MathCombinatorics+2	No attempts yet	1s	512 MB	Judgeable
Cul-De-Sac ParadesGiven a weighted tree, choose edge-disjoint paths that each start and end at a leaf, maximizing the total weight of the edges used.	Hard8	TreeDFS+2	No attempts yet	1s	512 MB	Judgeable
Shopping ChangesGiven a fixed change sequence and several wallets, find for each wallet the insertion position that minimizes the total inversion count after inserting the change block.	Hard8	Divide and conquerSorting+2	No attempts yet	2s	512 MB	Judgeable
Tasks for Indonesian ContestsGiven authors linked to contests and topics, each with at most two links, find the maximum number of tasks that can be written.	Hard8	GraphDFS+1	No attempts yet	1s	512 MB	Judgeable
Down We DigGiven n 8-character steps, for each prefix of steps determine the winner of a token game where a move from step i to j is legal when the Hamming similarity of the two steps is at least j-i.	Hard8	Game theoryDynamic programming+2	No attempts yet	5s	512 MB	Judgeable
Three MachinesCount pairs (a,b) with 1 <= a < b <= m from which three rewrite operations on integer pairs can generate every card (1, a_i).	Hard8	MathNumber theory+2	No attempts yet	2s	512 MB	Judgeable
Subway MapGiven a connected graph where some edge weights are unknown and a marked edge subset connects every node to node 1, find the minimum possible weight of each unknown edge so that the marked edges form a minimum spanning tree.	Hard8	Minimum spanning treeUnion-find+2	No attempts yet	4s	1024 MB	Judgeable
Cape and GunDecide whether the player can glide from S to E without touching ground, shooting left or right to clear monsters, and report the maximum number of monsters killed.	Hard8	GraphDynamic programming+1	No attempts yet	1s	256 MB	Judgeable
Ostap and chairsGiven N x-coordinates and N y-coordinates, find real k and b minimizing the sum of \|x_i - (k*y_i + b)\|.	Hard8	GeometryBinary search+2	No attempts yet	1s	256 MB	Judgeable
Witch DanceGiven N unit-length brooms that rotate clockwise at equal speed around fixed endpoints, decide whether any two brooms ever collide.	Hard8	GeometrySorting	No attempts yet	5s	1024 MB	Judgeable
Combine The GearsGiven a budget b, choose gear sizes with total cost at most b to maximize the number of distinct pointer-direction tuples, output as a natural logarithm.	Hard8	MathNumber theory+2	No attempts yet	2s	256 MB	Judgeable
Arrange and Count!Given a sequence, count modulo 1e9+7 how many distinct orderings the prefix-reversal-then-append operation can produce, over multiple test cases.	Hard8	CombinatoricsMath+2	No attempts yet	5s	512 MB	Judgeable
Rikka with Game TheoryCount the assignments of non-negative integers to the vertices of an undirected graph (n up to 17) where each vertex value equals the mex of its neighbors' values.	Hard8	Bit manipulationDynamic programming+1	No attempts yet	2s	512 MB	Judgeable
Ice Cream GameFor each query [L, R], decide the winner of a game that removes ends of an array without deleting the last copy of any kind, or print 0 if a kind is missing.	Hard8	Game theoryArray+1	No attempts yet	3s	1024 MB	Judgeable
The LocksmithMaintain a dynamic set of arithmetic progressions (a mod b) and answer point queries asking whether any active progression contains a given lock number.	Hard8	MathNumber theory+2	No attempts yet	1s	1024 MB	Judgeable
Sequence and Queries 40Given a sequence A and modulus M, each query shifts every value by d modulo M and asks for the start index of the k-th smallest suffix in lexicographic order.	Hard8	StringSorting+1	No attempts yet	2s	512 MB	Judgeable
Lamp ButtonsGiven which corridors each room's lamp lights, find the fewest lamps Ann must switch on to walk from room 1 to room N and end with only room N lit.	Hard8	GraphShortest path	No attempts yet	3s	1024 MB	Judgeable
Disc WorldSpend k spells, where each unit added to a cell costs p and raises its strength by 1, to maximize the shortest path from the top cell to the bottom cell.	Hard8	Shortest pathGraph+1	No attempts yet	4s	1024 MB	Judgeable
Space Station PromenadeA circular station has m windows on given modules that must be visited in order from module 1 and back; minimize total travel subject to equal clockwise and counterclockwise distances.	Hard8	Dynamic programmingPrefix sum+2	No attempts yet	1s	1024 MB	Judgeable
SkidorFind an L by L square with no trees whose height range is minimal, breaking ties by smallest top row then left column.	Hard8	Sliding windowHeap+2	No attempts yet	7s	1024 MB	Judgeable
Christmas ShoppingAssign each of K friends a distinct present from N items to maximize the total of the chosen liking values a[i][j].	Hard8	Dynamic programmingBit manipulation+2	No attempts yet	4s	1024 MB	Judgeable
Maze ConstructionBuild a labyrinth of rooms with red, green, and blue corridors where following the repeating color string S from the entrance never reaches the exit.	Hard8	GraphString+1	No attempts yet	3s	1024 MB	Judgeable
Decorative DominoesGiven an arrangement of n dominoes on a grid, assign each of the 2n ends an integer (0 to 10^6) so that touching ends share a number and no number appears more than twice, or report impossible.	Hard8	GraphDFS+2	No attempts yet	1s	512 MB	Judgeable
XOR Data StructureMaintain a multiset under add, delete-all-min, delete-all-max, and queries for the element minimizing or maximizing v XOR s.	Hard8	TrieBit manipulation+2	No attempts yet	2s	512 MB	Judgeable
MapleStoryGiven N hunting grounds with entry experience thresholds and per-minute rates, plus travel times, find the maximum experience obtainable within T minutes.	Hard8	Dynamic programmingShortest path+2	No attempts yet	2s	1024 MB	Judgeable
Space StationsEach station is a line segment, two axis-aligned or point contact connects them; for each query decide if two stations lie in the same connected component.	Hard8	Union-findGeometry+2	No attempts yet	2.5s	1024 MB	Judgeable
Divisor RitualGiven N cards with digits 1 to 9, count permutations where the last card's digit divides the number formed by the first N-1 cards, and output that probability.	Hard8	Bit manipulationDynamic programming+2	No attempts yet	1.75s	1024 MB	Judgeable
Maskpunk 2077Houses sit on a line with mask costs and edge travel times; handle point updates to travel times and queries for the cheapest mask reachable from a house within m minutes.	Hard8	Segment treeBinary search+2	No attempts yet	1s	1024 MB	Judgeable
The Formula Sicheol LovedCompute two nested-sum formulas involving gcd and lcm over all index pairs up to N, each reduced modulo a prime K, for N up to 10^6.	Hard8	Number theoryMath+2	No attempts yet	1s	1024 MB	Judgeable
KakaoTalkGiven N distinct lines, count pairs that intersect (meet at exactly one point), so parallel distinct lines and coincident lines do not count.	Hard8	GeometryHash map+2	No attempts yet	2s	1024 MB	Judgeable
Chair GameFind the fewest participants to add so that some run of K adjacent seated participants is guaranteed to match their chairs at some point as the seats rotate.	Hard8	ArrayNumber theory+1	No attempts yet	3s	1024 MB	Judgeable
Telephone Network Service with GoGiven edge speeds on a complete graph and per-vertex capacities, decide whether the total is N-1 and every vertex subset S has inner edge sum at most \|S\|-1.	Hard8	GraphMath	No attempts yet	1s	1024 MB	Judgeable
Game Developer SeungheePerform M operations on sequence A, each adding Bi to all elements then deleting multiples of 7 unless that would empty the sequence, and report the final sequence modulo 1e9+7.	Hard8	MathNumber theory+2	No attempts yet	1s	1024 MB	Judgeable
MagentaPaula and Marin move tokens on a tree whose edges are blue, red, or magenta, and the task is to decide whether Paula wins, Marin wins, or the game is a draw.	Hard8	Game theoryTree+1	No attempts yet	1s	512 MB	Judgeable