Problems

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Total results29,326 problems

Pickpockets
Hard8
Greedy, Binary search+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Efficient Partitioning
Hard8
Dynamic programming, Binary search+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Find the MST for Grid
Hard8
Minimum spanning tree, Greedy+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Generate the Sequences
Hard8
Combinatorics, Dynamic programming+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Multiple Parentheses
Hard8
Combinatorics, Dynamic programming+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Deleting
Hard8
Binary search, Dynamic programming+1
No attempts yet
Time limit
4s
Memory limit
512 MB
Judgeable
Fancy Formulas
Hard8
Math, Number theory+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Glory Graph
Hard8
Combinatorics, Graph+1
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Hamiltonian
Hard8
Implementation, Graph+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Little LCS
Hard8
Combinatorics, String+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Counting Pairs
Hard8
Graph, Sorting+2
No attempts yet
Time limit
4s
Memory limit
256 MB
Judgeable
Nimber Sequence
Hard8
Matrix, Math+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
PlayerUnknown's Battlegrounds
Hard8
Divide and conquer, Implementation+2
No attempts yet
Time limit
1.5s
Memory limit
256 MB
Judgeable
Sum
Hard8
Matrix, Math+1
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Historic Breakthrough
Hard8
Number theory, Math+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Yes, Prime Minister
Hard8
Math, Number theory+2
No attempts yet
Time limit
10s
Memory limit
512 MB
Judgeable
Command and Conquer: Red Alert 2
Hard8
Binary search, Greedy+1
No attempts yet
Time limit
10s
Memory limit
512 MB
Judgeable
Matryoshka Dolls
Hard8
Array, Sorting+2
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Nikanor Loves Games
Hard8
Math, Geometry+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Roads of the Empire
Hard8
Graph, Number theory+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Automatic Sprayer 2
Hard8
Math, Implementation+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Dynamic Short Path
Hard8
Shortest path, Graph+1
No attempts yet
Time limit
7.5s
Memory limit
1024 MB
Judgeable
Equivalent Pipelines
Hard8
Union-find, Sorting+2
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Flowerbed Redecoration
Hard8
Simulation, Matrix+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Organizing Beads
Hard8
Prefix sum, Sorting+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Periodic Ruler
Hard8
Math, Number theory+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Three Competitions
Hard8
Graph, Sorting+2
No attempts yet
Time limit
5s
Memory limit
1024 MB
Judgeable
Castles
Hard8
Tree, DFS+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
The Islands
Hard8
Dynamic programming, Geometry+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Sharing Chocolate
Hard8
Dynamic programming, Bit manipulation+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Cardiology
Hard8
Math, Number theory+1
No attempts yet
Time limit
2s
Memory limit
2048 MB
Judgeable
Domes
Hard8
Geometry, Combinatorics+2
No attempts yet
Time limit
2s
Memory limit
2048 MB
Judgeable
Ley Lines
Hard8
Geometry, Sorting+2
No attempts yet
Time limit
15s
Memory limit
2048 MB
Judgeable
Opportunity Cost
Hard8
Geometry, Binary search+2
No attempts yet
Time limit
5s
Memory limit
2048 MB
Judgeable
Quests
Hard8
Dynamic programming, Greedy+2
No attempts yet
Time limit
10s
Memory limit
2048 MB
Judgeable
’S No Problem
Hard8
Tree, DFS+2
No attempts yet
Time limit
2s
Memory limit
2048 MB
Judgeable
Trailing Digits
Hard8
Number theory, Math+2
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Limited Correspondence
Hard8
DFS, Backtracking+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
The Return of Carl
Hard8
Geometry, Shortest path+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Conduit Packing
Hard8
Geometry, Math+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Best Student
Hard8
Divide and conquer, Segment tree+2
No attempts yet
Time limit
1.2s
Memory limit
1024 MB
Judgeable
Colorful Tower of Hanoi
Hard8
Dynamic programming, Recursion+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Histogram
Hard8
Dynamic programming, Prefix sum+2
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Logistical Warehouse
Hard8
Tree, Binary search+2
No attempts yet
Time limit
4s
Memory limit
1024 MB
Judgeable
Similarity
Hard8
Divide and conquer, Sorting+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Twenty-Three
Hard8
Math, Dynamic programming+2
No attempts yet
Time limit
2.3s
Memory limit
1023 MB
Judgeable
Night Letter
Hard8
Shortest path, Graph+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Deceptive Directions
Hard8
BFS, Graph+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Hiring Help
Hard8
Geometry, Divide and conquer
No attempts yet
Time limit
4s
Memory limit
1024 MB
Judgeable
Intact Intervals
Hard8
Array, Hash map+2
No attempts yet
Time limit
6s
Memory limit
1024 MB
Judgeable
Line Fighter 2
Hard8
Geometry, Divide and conquer+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Squares
Hard8
Number theory, Math+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Elevator Operation
Hard8
Graph, Greedy+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
W3W (What 3 Words)
Hard8
String, Trie+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Cell Division
Hard8
Dynamic programming, Intervals+2
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
K-Calculator
Hard8
Linked list, Math+2
No attempts yet
Time limit
1.5s
Memory limit
512 MB
Judgeable
Minimum Spanning Cactus
Hard8
Graph, Tree+2
No attempts yet
Time limit
1.2s
Memory limit
512 MB
Judgeable
Matrix Partition
Hard8
Binary search, Brute force+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Hard All-Pairs Shortest Path
Hard8
Graph, Union-find+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Marble Launchers
Hard8
Graph, Shortest path+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Matrix Partition 2
Hard8
Dynamic programming, Prefix sum+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Digion
Hard8
Recursion, Combinatorics+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Flip
Hard8
Segment tree, Prefix sum+2
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
A Hard Problem
Hard8
Bit manipulation, Graph+2
No attempts yet
Time limit
20s
Memory limit
1024 MB
Judgeable
ICPC Kingdom
Hard8
Graph, Shortest path+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Sequence Operations
Hard8
Simulation, Implementation
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Construction
Hard8
Tree, DFS+2
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Beautiful Words
Hard8
String matching, Trie+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Inverting Everything
Hard8
Math, Tree+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Just Bootfall
Hard8
Dynamic programming, Graph+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Listing Passwords
Hard8
Union-find, String+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Festive Baobab
Hard8
Tree, Greedy+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Tote
Hard8
Dynamic programming, Probability+2
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Wooden pipeline
Hard8
Tree, DFS+2
No attempts yet
Time limit
3s
Memory limit
256 MB
Judgeable
Pulse Nova
Hard8
Geometry, Brute force
No attempts yet
Time limit
20s
Memory limit
256 MB
Judgeable
Russian Dolls on the Christmas Tree
Hard8
DFS, Segment tree+2
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Fire
Hard8
Binary search, Tree+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Flow
Hard8
Graph, Greedy+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Happiness
Hard8
Brute force, Sorting+2
No attempts yet
Time limit
5s
Memory limit
256 MB
Judgeable
Value
Hard8
Number theory, Dynamic programming+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
The Witcher
Hard8
Graph, Union-find+2
No attempts yet
Time limit
6s
Memory limit
512 MB
Judgeable
All in good fun!
Hard8
Geometry, Binary search+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Cheat
Hard8
Graph, DFS+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Yosupo's Algorithm
Hard8
Sorting, Segment tree
No attempts yet
Time limit
4s
Memory limit
1024 MB
Judgeable
Cookies
Hard8
Simulation, Sorting+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Sum Modulo
Hard8
Math, Probability+1
No attempts yet
Time limit
4s
Memory limit
1024 MB
Judgeable
Xor Sum
Hard8
Bit manipulation, Binary search+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Robots
Hard8
Dynamic programming, Greedy+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Matrix Inversion
Hard8
Matrix, Math+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Balanced Binary String
Hard8
String, Combinatorics+2
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Longest Lyndon Prefix
Hard8
String, String matching+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Program Optimization
Hard8
Simulation, Segment tree+1
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Knocking Down
Hard8
Geometry, Sorting+1
No attempts yet
Time limit
1s
Memory limit
64 MB
Judgeable
Rats
Hard8
String, Graph+2
No attempts yet
Time limit
0.75s
Memory limit
256 MB
Judgeable
Coins
Hard8
Math, Greedy+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Cakes
Hard8
Binary search, Greedy+2
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Partial Sums
Hard8
Math, Number theory+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Paternity Testing
Hard8
Tree, DFS+2
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Broken Sequence
Hard8
Backtracking, Brute force+1
No attempts yet
Time limit
4s
Memory limit
64 MB
Judgeable
Format a Table
Hard8
Brute force, Math+1
No attempts yet
Time limit
5s
Memory limit
64 MB
Judgeable

Title	Level	Topics	Solved	Time limit	Memory limit	Judge
PickpocketsEach day k allows stores 1..Ck to operate; assign at most T teams, each once and to a single store, to consecutive-day blocks so every clean store has one team each day, maximizing the minimum team income.	Hard8	GreedyBinary search+2	No attempts yet	2s	1024 MB	Judgeable
Efficient PartitioningPartition the array [0, N) into consecutive blocks and maximize the minimum over blocks of (b at block start) + (c at block end) + (sum of a in the block).	Hard8	Dynamic programmingBinary search+2	No attempts yet	2s	512 MB	Judgeable
Find the MST for GridGiven a grid graph whose edge weights come from four non-decreasing sequences, find the total weight of its minimum spanning tree.	Hard8	Minimum spanning treeGreedy+2	No attempts yet	2s	512 MB	Judgeable
Generate the SequencesCount the ordered tuples of sequences built from (1) by repeatedly appending 1 or m, or inserting any integer strictly between two adjacent elements, modulo 998244353.	Hard8	CombinatoricsDynamic programming+2	No attempts yet	2s	512 MB	Judgeable
Multiple ParenthesesCount ways to place a regular bracket sequence in each of N boxes so the total number of opening brackets is M and no box holds a sequence of length 2K, modulo 998244353.	Hard8	CombinatoricsDynamic programming+2	No attempts yet	2s	512 MB	Judgeable
DeletingGiven the array 1 to n, delete adjacent pairs n/2 times so that the largest deletion cost is as small as possible, and output that minimum.	Hard8	Binary searchDynamic programming+1	No attempts yet	4s	512 MB	Judgeable
Fancy FormulasGiven a prime p and pairs (a,b) with a+b not divisible by p, find the minimum number of operations to transform one pair into another, or report impossibility.	Hard8	MathNumber theory+2	No attempts yet	2s	512 MB	Judgeable
Glory GraphGiven a complete graph on n vertices with yellow and blue edges, compute Y minus A, the difference between two counts of 4-vertex subgraphs.	Hard8	CombinatoricsGraph+1	No attempts yet	3s	512 MB	Judgeable
HamiltonianGiven K up to 60, build a graph with at most 20 vertices that has exactly K unordered vertex pairs joined by a Hamiltonian path. The output is the graph's edge list.	Hard8	ImplementationGraph+1	No attempts yet	2s	512 MB	Judgeable
Little LCSCount the ways to fill the question marks in two good ternary strings of length 2n+1 so that their LCS is exactly n.	Hard8	CombinatoricsString+1	No attempts yet	2s	512 MB	Judgeable
Counting PairsGiven an undirected multigraph with self-loops, count pairs of vertices whose combined incident-edge count exceeds k for each of up to 10^6 queries.	Hard8	GraphSorting+2	No attempts yet	4s	256 MB	Judgeable
Nimber SequenceGiven a recurrence over nimbers using nim sum and nim product, find the m-th term a_m for m up to 10^18.	Hard8	MatrixMath+1	No attempts yet	1s	256 MB	Judgeable
PlayerUnknown's BattlegroundsFor each value x, count the subgrids whose minimum equals x, given an n by m grid holding a permutation of 1 to n*m.	Hard8	Divide and conquerImplementation+2	No attempts yet	1.5s	256 MB	Judgeable
SumGiven an n by m matrix modulo a prime p, find K rank-one style pairs of vectors b and c whose sum of outer products equals the matrix, with nonzero row and column sums.	Hard8	MatrixMath+1	No attempts yet	3s	512 MB	Judgeable
Historic BreakthroughGiven m, find n such that m equals the sum of integers in 1..n coprime to n, which also equals n*phi(n)/2.	Hard8	Number theoryMath+2	No attempts yet	2s	512 MB	Judgeable
Yes, Prime MinisterFor each x, find the shortest interval [l, r] containing x whose sum of consecutive integers is prime, or report -1.	Hard8	MathNumber theory+2	No attempts yet	10s	512 MB	Judgeable
Command and Conquer: Red Alert 2Find the smallest Chebyshev range k so a sniper moving only in +x, +y, or +z steps from far away can cover all enemies in 3D.	Hard8	Binary searchGreedy+1	No attempts yet	10s	512 MB	Judgeable
Matryoshka DollsFor each query segment, repeatedly remove the minimum and sum the index distances to the next smallest element until one element remains.	Hard8	ArraySorting+2	No attempts yet	5s	512 MB	Judgeable
Nikanor Loves GamesChoose positive integers a and b for one coin, paying a*b, to maximize expected winnings across n friends whose two-sided coins are known, where ties go to Nikanor.	Hard8	MathGeometry+2	No attempts yet	1s	512 MB	Judgeable
Roads of the EmpireFor each query (n, u, v), build the graph on 1..n with an edge x-y when y divides x+n (x<y), then output the shortest path length between u and v, or -1 if unreachable.	Hard8	GraphNumber theory+2	No attempts yet	2s	512 MB	Judgeable
Automatic Sprayer 2Given the matrix E where E[i][j] is the total Manhattan-distance-weighted spray from all cells, reconstruct any nonnegative integer matrix A that produces it.	Hard8	MathImplementation+2	No attempts yet	2s	1024 MB	Judgeable
Dynamic Short PathOn a complete directed graph with weights 0 to 2, answer shortest distances capped at 2 for each query and apply up to 2000 edge weight updates.	Hard8	Shortest pathGraph+1	No attempts yet	7.5s	1024 MB	Judgeable
Equivalent PipelinesGiven d weighted spanning trees on n vertices, two trees are equivalent when the minimum edge weight on the path between every pair of vertices is the same; group each tree with the earliest equivalent one.	Hard8	Union-findSorting+2	No attempts yet	3s	1024 MB	Judgeable
Flowerbed RedecorationGiven a grid and a sliding d by d window that rotates 90 degrees clockwise at each stop, output the grid after the full scan order is applied.	Hard8	SimulationMatrix+1	No attempts yet	3s	1024 MB	Judgeable
Organizing BeadsAfter each toggle of a cell, report the minimum pushes to gather all beads into a contiguous block at the left or right end of the barrel.	Hard8	Prefix sumSorting+2	No attempts yet	2s	1024 MB	Judgeable
Periodic RulerGiven colors at up to 50 integer positions, find every positive integer that cannot be the minimal period of the full coloring, and report how many such numbers exist and their sum.	Hard8	MathNumber theory+2	No attempts yet	2s	1024 MB	Judgeable
Three CompetitionsEach person has ranks in three competitions; a directly wins against b if a beats b in at least two, and queries ask whether a reaches b through such direct wins.	Hard8	GraphSorting+2	No attempts yet	5s	1024 MB	Judgeable
CastlesGiven a tree of castles with attack, death, and garrison costs, find the smallest army that can capture and hold every castle while traversing each edge at most twice.	Hard8	TreeDFS+2	No attempts yet	2s	1024 MB	Judgeable
The IslandsTwo monotone passes across islands in increasing x order visit every island, with the two special islands split between the passes; find the shortest total tour and print the visiting order.	Hard8	Dynamic programmingGeometry+2	No attempts yet	2s	1024 MB	Judgeable
Sharing ChocolateDecide whether a rectangular chocolate bar can be broken along grid lines into exactly n rectangular pieces with given sizes, using each piece once.	Hard8	Dynamic programmingBit manipulation+2	No attempts yet	2s	1024 MB	Judgeable
CardiologyGiven r rows and c columns, choose the column to collect second so the stable position is nearest the center, and report that position and the iteration count.	Hard8	MathNumber theory+1	No attempts yet	2s	2048 MB	Judgeable
DomesGiven n domes inside a rectangle and a target left-to-right order, find the area of points in the rectangle from which the domes appear in that order in a 180-degree photo.	Hard8	GeometryCombinatorics+2	No attempts yet	2s	2048 MB	Judgeable
Ley LinesGiven n points with no three collinear and a pencil thickness t, find the largest number of points that can be covered by a single strip of width t.	Hard8	GeometrySorting+2	No attempts yet	15s	2048 MB	Judgeable
Opportunity CostGiven n triples, find the point minimizing the maximum over all points of the sum of positive coordinate gaps, and report its index.	Hard8	GeometryBinary search+2	No attempts yet	5s	2048 MB	Judgeable
QuestsOrder all n quests to maximize total XP, where a quest finished below its target level d pays c times its XP instead of x.	Hard8	Dynamic programmingGreedy+2	No attempts yet	10s	2048 MB	Judgeable
’S No ProblemGiven a weighted tree, place two routes (closed walks, ends free) that together cover every edge, minimizing total length.	Hard8	TreeDFS+2	No attempts yet	2s	2048 MB	Judgeable
Trailing DigitsGiven a per-item price b, a digit d, and a huge maximum price a, find the largest count of trailing d's achievable by a multiple of b not exceeding a.	Hard8	Number theoryMath+2	No attempts yet	1s	2048 MB	Judgeable
Limited CorrespondenceGiven up to 11 pairs of strings, find the shortest non-empty sequence of distinct pair indices whose concatenated left strings equal the concatenated right strings, breaking ties lexicographically.	Hard8	DFSBacktracking+2	No attempts yet	1s	1024 MB	Judgeable
The Return of CarlCompute the shortest path along the surface of a regular octahedron between two points given in spherical coordinates, for multiple test cases.	Hard8	GeometryShortest path+2	No attempts yet	2s	1024 MB	Judgeable
Conduit PackingGiven four wire diameters, find the smallest enclosing circle diameter that holds all four circular cross sections without overlap, and round it to the nearest micrometer.	Hard8	GeometryMath+2	No attempts yet	2s	1024 MB	Judgeable
Best StudentFor each query interval in an array of student ids, print the id that occurs most often, breaking ties by the largest id.	Hard8	Divide and conquerSegment tree+2	No attempts yet	1.2s	1024 MB	Judgeable
Colorful Tower of HanoiFind the fewest moves to shift a Hanoi tower with repeated disk sizes, where each color sets whether that size's order must reverse, stay, or not matter.	Hard8	Dynamic programmingRecursion+1	No attempts yet	1s	1024 MB	Judgeable
HistogramGiven a frequency array over values 1..n, split it into at most B contiguous buckets minimizing the total sum of squared deviations from each bucket's mean.	Hard8	Dynamic programmingPrefix sum+2	No attempts yet	3s	1024 MB	Judgeable
Logistical WarehouseChoose k centers at integer points on a weighted tree to minimize the maximum weighted distance from any node to its nearest center.	Hard8	TreeBinary search+2	No attempts yet	4s	1024 MB	Judgeable
SimilarityGiven two length-n sequences p and q, count triples i<j<k with p_i<p_j<p_k and q_i<q_j<q_k.	Hard8	Divide and conquerSorting+2	No attempts yet	1s	1024 MB	Judgeable
Twenty-ThreeFind the k-th smallest number that can be written as a sum of repunit-like numbers made only of the digits 2 and 3 (23, 2323, ...).	Hard8	MathDynamic programming+2	No attempts yet	2.3s	1023 MB	Judgeable
Night LetterFor each query (C, s, e), find the shortest path from s to e that avoids intermediate houses with index at least C.	Hard8	Shortest pathGraph+2	No attempts yet	1s	1024 MB	Judgeable
Deceptive DirectionsGiven a grid and a sabotaged instruction string where each step was replaced by a different direction, mark every cell that could be the treasure.	Hard8	BFSGraph+2	No attempts yet	2s	1024 MB	Judgeable
Hiring HelpFor each consultant request, decide whether the current coders can match its lines and bugs per hour, with coders removed over time.	Hard8	GeometryDivide and conquer	No attempts yet	4s	1024 MB	Judgeable
Intact IntervalsCount the ways to cut a circular array into at least two contiguous arcs so that each arc's multiset equals the corresponding multiset of the target array b.	Hard8	ArrayHash map+2	No attempts yet	6s	1024 MB	Judgeable
Line Fighter 2Given N lines and Q queries (x, a), output the maximum (a=1) or minimum (a=2) value among all lines at x, within 1e-4 error.	Hard8	GeometryDivide and conquer+2	No attempts yet	1s	1024 MB	Judgeable
SquaresGiven N up to 10^18 whose prime factors are all at most 100000, output four non-negative integers whose squares sum to N.	Hard8	Number theoryMath+2	No attempts yet	2s	1024 MB	Judgeable
Elevator OperationEach floor holds one person with a known destination; drive a one-person elevator from floor 1 so everyone reaches their target floor using the fewest button presses, and output one optimal button order.	Hard8	GraphGreedy+2	No attempts yet	1s	512 MB	Judgeable
W3W (What 3 Words)Count how many distinct ordered triples of words (repetition allowed) can be joined with dots to form a code whose dot-stripped version equals the queried string S.	Hard8	StringTrie+2	No attempts yet	1s	512 MB	Judgeable
Cell DivisionGiven a mutation rule for each of N cell types and an initial cell, decide whether the observed final string could have been produced by the division process.	Hard8	Dynamic programmingIntervals+2	No attempts yet	3s	512 MB	Judgeable
K-CalculatorEvaluate an expression of rational operands by repeatedly applying the operator selected by u_i XOR the modular value of the previous result, removing it and merging its operands.	Hard8	Linked listMath+2	No attempts yet	1.5s	512 MB	Judgeable
Minimum Spanning CactusGiven a weighted cactus graph, print the minimum-cost spanning cactus, then after each edge-weight update print the new minimum spanning cactus cost.	Hard8	GraphTree+2	No attempts yet	1.2s	512 MB	Judgeable
Matrix PartitionCut an n by m grid with exactly a horizontal and b vertical cuts, maximizing no piece, and report the smallest possible largest piece sum.	Hard8	Binary searchBrute force+2	No attempts yet	1s	1024 MB	Judgeable
Hard All-Pairs Shortest PathIn a connected graph where exactly one edge has weight 1 and all others weight 0, compute the sum of shortest-path distances over all vertex pairs.	Hard8	GraphUnion-find+2	No attempts yet	1s	1024 MB	Judgeable
Marble LaunchersRotate marble launchers at per-45-degree cost so a marble fired from launcher s reaches launcher e, minimizing total rotation cost and outputting the path.	Hard8	GraphShortest path+2	No attempts yet	1s	1024 MB	Judgeable
Matrix Partition 2Given an n by m matrix, choose a horizontal and b vertical cut lines so the largest sum among the resulting parts is minimized.	Hard8	Dynamic programmingPrefix sum+2	No attempts yet	2s	1024 MB	Judgeable
DigionGiven a Digion string built from nesting rule (A)B, output the next Digion in the weight-then-inner-then-outer ordering.	Hard8	RecursionCombinatorics+2	No attempts yet	2s	1024 MB	Judgeable
FlipMaintain a binary array under range bit flips and report how many subarrays inside a query range are alternating.	Hard8	Segment treePrefix sum+2	No attempts yet	3s	1024 MB	Judgeable
A Hard ProblemAssign values to unknown nodes of a graph so that xor-popcount edge weights are minimized while q bit-level equality constraints hold.	Hard8	Bit manipulationGraph+2	No attempts yet	20s	1024 MB	Judgeable
ICPC KingdomPick exactly k roads that form no cycle and can each be assigned to a different worker, maximizing the sum of floor(sqrt(a_u + a_v)) for each k.	Hard8	GraphShortest path+2	No attempts yet	2s	1024 MB	Judgeable
Sequence OperationsDecide whether sequence C can be turned into D by inserting or deleting strictly increasing runs of length at least M, and output the operations.	Hard8	SimulationImplementation	No attempts yet	1s	512 MB	Judgeable
ConstructionGiven a tree, answer queries asking whether two vertices stay connected after deleting a single vertex or a single tree edge.	Hard8	TreeDFS+2	No attempts yet	5s	512 MB	Judgeable
Beautiful WordsGiven a string A and a set of strings S, find the minimum over all cyclic rotations of A of the longest substring that appears in some string of S.	Hard8	String matchingTrie+2	No attempts yet	1s	1024 MB	Judgeable
Inverting EverythingCount the city subsets whose flipping turns the active railroads of a complete graph into a spanning tree, modulo 1e9+7.	Hard8	MathTree+1	No attempts yet	1s	1024 MB	Judgeable
Just BootfallAssign N players to M ordered positions, scoring each player's position value minus C times the distance for every best-friend pair, and maximize total team performance.	Hard8	Dynamic programmingGraph+2	No attempts yet	1s	1024 MB	Judgeable
Listing PasswordsCount the 0/1 strings of length N that fit the fixed digits and M required palindrome intervals, modulo 1e9+7, or 0 on conflict.	Hard8	Union-findString+1	No attempts yet	3s	1024 MB	Judgeable
Festive BaobabPlace t unit-weight decorations on nodes of a rooted tree; each node i allows total weight in its subtree up to w_i, and each decoration on node i gives d_i joy. Maximize total joy.	Hard8	TreeGreedy+2	No attempts yet	2s	512 MB	Judgeable
ToteGiven match outcome probabilities and ticket types with fixed counts of single, double and triple bets, choose how many tickets of each type to buy within budget S to maximize expected prize money.	Hard8	Dynamic programmingProbability+2	No attempts yet	2s	256 MB	Judgeable
Wooden pipelineFor each city u in a tree, root the tree at u, then find the maximum flow from all leaves to u when only leaves can supply water.	Hard8	TreeDFS+2	No attempts yet	3s	256 MB	Judgeable
Pulse NovaPlace a circle of radius R so that the total length of the given lines' segments inside the circle is maximized.	Hard8	GeometryBrute force	No attempts yet	20s	256 MB	Judgeable
Russian Dolls on the Christmas TreeFor each node of a tree, consider the set of labels in its subtree and report the largest number of consecutive labels that can be chained into a stable nesting.	Hard8	DFSSegment tree+2	No attempts yet	3s	1024 MB	Judgeable
FireGiven a tree whose vertex temperatures drop by 1 each morning, find the latest day Pang can prepare to leave vertex 1 and still cast magic once on every vertex, or report -1.	Hard8	Binary searchTree+2	No attempts yet	1s	256 MB	Judgeable
FlowGiven a graph that is k vertex-independent paths from 1 to n, move capacity between edges at unit cost to maximize the max flow, and output the minimum number of moves.	Hard8	GraphGreedy+2	No attempts yet	1s	256 MB	Judgeable
HappinessGiven other teams' submission data, choose the order Pang solves his known problems (each takes a fixed time plus 20 penalty per rejection) to maximize his total happiness from ranking, medals, and special first/last-solve bonuses.	Hard8	Brute forceSorting+2	No attempts yet	5s	256 MB	Judgeable
ValueChoose a subset of 1..n maximizing the sum of a_i minus b_j for every selected pair where j is a higher power of i.	Hard8	Number theoryDynamic programming+2	No attempts yet	1s	256 MB	Judgeable
The WitcherGiven an undirected multigraph where some edges are mandatory, choose a subset of optional edges so that every vertex ends up with even degree, or report that this is impossible.	Hard8	GraphUnion-find+2	No attempts yet	6s	512 MB	Judgeable
All in good fun!Given three non-parallel lines, find the minimum possible value of the largest distance from a point to any of the three lines.	Hard8	GeometryBinary search+2	No attempts yet	1s	512 MB	Judgeable
CheatGiven a directed graph with edges i to i+1, list every vertex that lies on all cycles, or all vertices if the graph has no cycle.	Hard8	GraphDFS+2	No attempts yet	2s	512 MB	Judgeable
Yosupo's AlgorithmGiven red and blue weighted points, answer each query by picking a red and a blue point that satisfy the y-order and L, R split conditions, maximizing their total weight.	Hard8	SortingSegment tree	No attempts yet	4s	1024 MB	Judgeable
CookiesFor each k, find the total sweetness left after M children each add a cookie and eat the sweetest or bitterest one, with the input decrypted online.	Hard8	SimulationSorting+1	No attempts yet	3s	1024 MB	Judgeable
Sum ModuloGiven a generator that outputs 1 to N with weights A_i, find the expected number of draws until the running sum modulo M first equals K, printed modulo 998244353.	Hard8	MathProbability+1	No attempts yet	4s	1024 MB	Judgeable
Xor SumFind the minimum possible maximum of N nonnegative integers whose sum is S and whose XOR is X, or report -1 if no such sequence exists.	Hard8	Bit manipulationBinary search+1	No attempts yet	2s	1024 MB	Judgeable
RobotsGiven N robots and N antennas on a line, activate antennas one at a time so each pulls its nearest remaining robot; minimize total distance moved and output an order.	Hard8	Dynamic programmingGreedy+2	No attempts yet	2s	1024 MB	Judgeable
Matrix InversionFill an N by N grid with the integers 1 to N^2 so that the inversion number of the row-major reading is X and the column-major reading is Y, or report that it is impossible.	Hard8	MatrixMath+1	No attempts yet	1s	1024 MB	Judgeable
Balanced Binary StringCount the ways to replace each '?' in a circular binary string with 0 or 1 so that every two circular substrings of the same length contain numbers of 1s differing by at most one, modulo 1e9+7.	Hard8	StringCombinatorics+2	No attempts yet	3s	512 MB	Judgeable
Longest Lyndon PrefixFor each suffix of a lowercase string, find the length of its longest prefix that is a Lyndon word.	Hard8	StringString matching+1	No attempts yet	1s	256 MB	Judgeable
Program OptimizationSimulate the given C++ program exactly, including its mt19937 random sequence, while answering range mex queries over a permuted array fast enough for q up to 10^7.	Hard8	SimulationSegment tree+1	No attempts yet	2s	256 MB	Judgeable
Knocking DownPick one point of a rectangle to pin, rotate it around that point, and find the fewest flags the sweep must knock down.	Hard8	GeometrySorting+1	No attempts yet	1s	64 MB	Judgeable
RatsGiven an infinite periodic string A and a set S of strings, find the minimum number of strings from S whose concatenation forms a string B that tiles the line identically to A.	Hard8	StringGraph+2	No attempts yet	0.75s	256 MB	Judgeable
CoinsPlace N coins on an N by N board so each row and column holds one coin, moving coins one step at a time with no collisions, and minimize total moves.	Hard8	MathGreedy+2	No attempts yet	1s	128 MB	Judgeable
CakesThree eaters with different per-cake speeds share n cakes, each cake splittable into any proportions; find the minimum makespan.	Hard8	Binary searchGreedy+2	No attempts yet	3s	512 MB	Judgeable
Partial SumsRepeatedly apply the 2D prefix-sum map over GF(2) to a binary matrix and find the smallest positive number of applications that returns the original matrix.	Hard8	MathNumber theory+2	No attempts yet	1s	256 MB	Judgeable
Paternity TestingGiven a rooted tree, answer queries that sum cnt(i, l, r) over i in [l, r], where cnt counts subtree nodes with labels in a range; queries are encoded online by the previous answer.	Hard8	TreeDFS+2	No attempts yet	3s	512 MB	Judgeable
Broken SequenceFill in the missing +1 and -1 values of four partly known sequences so that they form a Turyn-type sequence.	Hard8	BacktrackingBrute force+1	No attempts yet	4s	64 MB	Judgeable
Format a TableGiven a 3x3 table of cell text lengths and a total width w, split w into three column widths that minimize the sum of the three row heights.	Hard8	Brute forceMath+1	No attempts yet	5s	64 MB	Judgeable