Problems

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Total results29,278 problems

Similarity Graph
Hard8
Graph, Topological sort+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Squirrel Game
Hard8
Game theory, Dynamic programming+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Two Paths
Hard8
Tree, Dynamic programming+1
No attempts yet
Time limit
5s
Memory limit
1024 MB
Judgeable
The Beauty of Cycles
Hard8
Number theory, Math
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Traffic on the Way Home
Hard8
Binary search, Tree+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Hard Problem
Hard8
Divide and conquer, Stack+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
String Strange Sum
Hard8
String matching, String+1
No attempts yet
Time limit
4s
Memory limit
1024 MB
Judgeable
Triangular Cactus Paths
Hard8
Graph, Tree+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
K-Item Shopping Spree
Hard8
Math, Dynamic programming+1
No attempts yet
Time limit
10s
Memory limit
1024 MB
Judgeable
달나라에 사는 토끼와 우주에서 떨어지는 떡
Hard8
Tree, Graph+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Battle Simulation
Hard8
Prefix sum, Binary search+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Kermode Bear's Salmon Hunt
Hard8
Game theory, Graph+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Prime Arrangement
Hard8
Combinatorics, Sorting+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Darkest Dungeon
Hard8
Tree, Dynamic programming+1
No attempts yet
Time limit
1.5s
Memory limit
1024 MB
Judgeable
Hug Me
Hard8
Dynamic programming, Divide and conquer+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Longest Shortest Paths
Hard8
Geometry, Graph+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Rectangles
Hard8
Divide and conquer, Segment tree+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
LCS 9
Hard8
Dynamic programming, String
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
K-Queen
Hard8
Sorting, Implementation+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Formula Flatland
Hard8
Graph, BFS+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Foreign Football
Hard8
String matching, String+1
No attempts yet
Time limit
5s
Memory limit
1024 MB
Judgeable
Junk Journey
Hard8
Simulation, Implementation+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Keyboard Queries
Hard8
Union-find, String matching+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
GomGom and Tetris
Hard8
Game theory, Bit manipulation+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
AND vs OR
Hard8
Bit manipulation, Divide and conquer+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Card Game
Hard8
Game theory, Dynamic programming+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Empty Quadrilaterals
Hard8
Geometry, Dynamic programming+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Frog Jump
Hard8
Intervals, Binary search+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Linear Regression
Hard8
Geometry, Binary search+1
No attempts yet
Time limit
5s
Memory limit
1024 MB
Judgeable
Longest Substring
Hard8
String matching, Tree
No attempts yet
Time limit
5s
Memory limit
1024 MB
Judgeable
SubsetMex
Hard8
Greedy, Dynamic programming+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Lego Wall
Hard8
Combinatorics, Dynamic programming+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Take On Meme
Hard8
Tree, Geometry+1
No attempts yet
Time limit
4s
Memory limit
1024 MB
Judgeable
Unbroken Spirit 2
Hard8
Greedy, Heap+1
No attempts yet
Time limit
1.5s
Memory limit
1024 MB
Judgeable
Unbroken Spirit 3
Hard8
Dynamic programming, Greedy+1
No attempts yet
Time limit
6s
Memory limit
1024 MB
Judgeable
Alternating Algorithm
Hard8
Sorting, Simulation+1
No attempts yet
Time limit
7s
Memory limit
1024 MB
Judgeable
Faster Than Light
Hard8
Geometry, Sorting+1
No attempts yet
Time limit
10s
Memory limit
1024 MB
Judgeable
Kebab Pizza
Hard8
Graph, Implementation
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Mortgage
Hard8
Prefix sum, Divide and conquer+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Kalel, the Jumping Frog
Hard8
Dynamic programming, Matrix+1
No attempts yet
Time limit
18s
Memory limit
1024 MB
Judgeable
Silver Tree
Hard8
Tree, Math+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Winter Forest and the Magic Flame
Hard8
Tree, Greedy+1
No attempts yet
Time limit
1.5s
Memory limit
512 MB
Judgeable
Expected length of the minimum cycle
Hard8
Combinatorics, Math
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Flying Doors
Hard8
Sorting, Greedy+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Tickets
Hard8
Tree, Divide and conquer+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Simple Math Problem
Hard8
Combinatorics, Math+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Reimu's Teleportation Practice
Hard8
Tree, Dynamic programming+1
No attempts yet
Time limit
6s
Memory limit
1024 MB
Judgeable
BinCoin
Hard8
Tree, Probability+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Cactus Meets Torus
Hard8
Graph, DFS+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Dominoes
Hard8
Graph, DFS+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Game of Questions
Hard8
Dynamic programming, Bit manipulation+1
No attempts yet
Time limit
5s
Memory limit
1024 MB
Judgeable
AibohphobiA
Hard8
Graph, DFS+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Balanced Seesaw Array
Hard8
Segment tree, Math+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Invitation
Hard8
Combinatorics, Sorting+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Under Construction Forever
Hard8
Graph, Dynamic programming+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Knightmare
Hard8
Segment tree, Sorting+1
No attempts yet
Time limit
5s
Memory limit
1024 MB
Judgeable
Gold Rush
Hard8
Divide and conquer, Dynamic programming+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Knight Moves: Black Edition
Hard8
Math, Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Who is closer
Hard8
Bit manipulation, Divide and conquer+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
DeCSS 3
Hard8
Backtracking, Bit manipulation+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
DeCSS 4
Hard8
Bit manipulation, Brute force+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
DeCSS 5
Hard8
Brute force, Math+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
DeCSS 6
Hard8
Bit manipulation, Brute force+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
DeCSS 7
Hard8
Bit manipulation, Math+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
DeCSS 9
Hard8
Brute force, Math+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Neboderi
Hard8
Sliding window, Number theory+1
No attempts yet
Time limit
2.5s
Memory limit
1024 MB
Judgeable
Lampice
Hard8
Prefix sum, Dynamic programming+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Expected Cycle Size
Hard8
Probability, Combinatorics+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Folding
Hard8
String matching, Math+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
MFP: Most Fluctuated Player
Hard8
Segment tree, Sorting+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Qarentheziz Sequence
Hard8
Segment tree, String+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Sequence and Queries 41
Hard8
Segment tree, Dynamic programming
No attempts yet
Time limit
5s
Memory limit
1024 MB
Judgeable
Palindrome
Hard8
String matching, Two pointers+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Tennis
Hard8
Dynamic programming, Math+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Quadratic Functions and a Line
Hard8
Geometry, Math+1
No attempts yet
Time limit
0.1s
Memory limit
1024 MB
Judgeable
Maximum Absolute Value of the Product of Interval Sums
Hard8
Dynamic programming, Prefix sum+1
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Stone Game and Queries
Hard8
Number theory, Math+1
No attempts yet
Time limit
1.5s
Memory limit
512 MB
Judgeable
Card Game
Hard8
Game theory, Graph+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Hilbert Billiards
Hard8
Simulation, Math+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Permutation
Hard8
Combinatorics, Math+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Carcassonne
Hard8
Matrix, BFS+1
No attempts yet
Time limit
5s
Memory limit
1024 MB
Judgeable
Magic Towers
Hard8
Geometry, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Alps Cable Car 2
Hard8
Dynamic programming, Geometry+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Babel Tower
Hard8
Stack, Greedy+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Sotteok-Sotteok 2
Hard8
Segment tree, Dynamic programming+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Tea
Hard8
Math, Sorting+1
No attempts yet
Time limit
8s
Memory limit
1024 MB
Judgeable
Concurrent Programming
Hard8
Greedy, Simulation+2
No attempts yet
Time limit
9s
Memory limit
1024 MB
Judgeable
Three Roads
Hard8
Graph, DFS+1
No attempts yet
Time limit
8s
Memory limit
1024 MB
Judgeable
Exhibition
Hard8
Dynamic programming, Binary search+1
No attempts yet
Time limit
9s
Memory limit
1024 MB
Judgeable
Online Shop Ranking
Hard8
Array, Prefix sum+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Vials 2
Hard8
Graph, Two pointers+1
No attempts yet
Time limit
10s
Memory limit
1024 MB
Judgeable
Raises
Hard8
Dynamic programming, Greedy+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Bajtessi's Dribbling
Hard8
Dynamic programming, String+1
No attempts yet
Time limit
9s
Memory limit
1024 MB
Judgeable
Spanning Trees
Hard8
Number theory, Graph+1
No attempts yet
Time limit
8s
Memory limit
1024 MB
Judgeable
Tightrope Walking
Hard8
Graph, BFS+1
No attempts yet
Time limit
6s
Memory limit
1024 MB
Judgeable
Bracket Partitions
Hard8
Dynamic programming, Binary search+1
No attempts yet
Time limit
7s
Memory limit
1024 MB
Judgeable
Agents
Hard8
Tree, Binary search+2
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Parentheses
Hard8
Graph, Greedy+1
No attempts yet
Time limit
4s
Memory limit
1024 MB
Judgeable
Gang of Biciaks
Hard8
Tree, Divide and conquer+1
No attempts yet
Time limit
12s
Memory limit
1024 MB
Judgeable
Kindergarten
Hard8
Graph, Combinatorics+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable

Title	Level	Topics	Solved	Time limit	Memory limit	Judge
Similarity GraphGiven a graph on N vertices, find two permutations p and q whose similarity graph equals it, or report NO if none exists.	Hard8	GraphTopological sort+1	No attempts yet	1s	1024 MB	Judgeable
Squirrel GameTwinkle and Nova alternately place acorns on empty stones left of some squirrel, and the player with no legal move loses. Find the winner.	Hard8	Game theoryDynamic programming+1	No attempts yet	3s	1024 MB	Judgeable
Two PathsGiven a weighted tree and queries (u, v, A, B), find vertex-disjoint paths from u and from v that maximize A times the first path weight plus B times the second.	Hard8	TreeDynamic programming+1	No attempts yet	5s	1024 MB	Judgeable
The Beauty of CyclesGiven n, m, and base k, count the distinct purely cyclic base-k reals that can be written as x/y with 1 <= x <= n and 1 <= y <= m.	Hard8	Number theoryMath	No attempts yet	2s	1024 MB	Judgeable
Traffic on the Way HomeGiven a tree with cars on some nodes, find the minimum minutes for every car to reach node 1 and leave, with one car per node at a time.	Hard8	Binary searchTree+1	No attempts yet	1s	512 MB	Judgeable
Hard ProblemSum (last element + 10) times f_m over even-length subsegments whose two halves have maxima differing by at most k, modulo 998244353.	Hard8	Divide and conquerStack+1	No attempts yet	1s	1024 MB	Judgeable
String Strange SumGiven a lowercase string s, sum over all segments [l, r] with 2 <= l <= r <= \|s\| the longest suffix of s[1, l-1] that splits into prefixes of s[l, r].	Hard8	String matchingString+1	No attempts yet	4s	1024 MB	Judgeable
Triangular Cactus PathsCount simple paths of exact length k between s and f in a triangular cactus graph for each query, modulo 998244353.	Hard8	GraphTree+1	No attempts yet	2s	1024 MB	Judgeable
K-Item Shopping SpreeCount length-k sequences of item indices (repeats and order allowed) whose prices sum to each query target, modulo 997.	Hard8	MathDynamic programming+1	No attempts yet	10s	1024 MB	Judgeable
달나라에 사는 토끼와 우주에서 떨어지는 떡Rabbits on a directed functional graph walk shortest paths to each falling rice cake's vertex, and the task is to find each rabbit's total jump count.	Hard8	TreeGraph+2	No attempts yet	1s	1024 MB	Judgeable
Battle SimulationGiven a segment of soldiers with signed combat powers, split it into two contiguous teams of at most two-thirds of the size each and minimize the power difference.	Hard8	Prefix sumBinary search+1	No attempts yet	2s	1024 MB	Judgeable
Kermode Bear's Salmon HuntTwo bears alternately place salmon on empty vertices that have a unique simple path from a salmon vertex. Find which bear is stuck when no move is left.	Hard8	Game theoryGraph+2	No attempts yet	1s	1024 MB	Judgeable
Prime ArrangementGiven RC distinct primes, count the ways to fill an R by C grid so that each row's product has a prescribed rank among all row products.	Hard8	CombinatoricsSorting+1	No attempts yet	1s	1024 MB	Judgeable
Darkest DungeonGiven a tree of N rooms and a limit of K passages, find a start room and a walk crossing at most K passages that visits the most distinct rooms.	Hard8	TreeDynamic programming+1	No attempts yet	1.5s	1024 MB	Judgeable
Hug MeGiven N points with distinct heights, find for each query point the most points a downward path can pass, where each step drops no more than it moves sideways.	Hard8	Dynamic programmingDivide and conquer+1	No attempts yet	2s	1024 MB	Judgeable
Longest Shortest PathsGiven rectangles and two vertical segments in the plane, find the largest shortest-path length between any point on S and any point on T.	Hard8	GeometryGraph+2	No attempts yet	2s	1024 MB	Judgeable
RectanglesCount the axis-parallel rectangles whose four vertices all belong to a given set of up to 70,000 distinct points.	Hard8	Divide and conquerSegment tree+1	No attempts yet	2s	1024 MB	Judgeable
LCS 9Given strings A and B, sum the LCS lengths over every prefix of A paired with every substring of B.	Hard8	Dynamic programmingString	No attempts yet	2s	1024 MB	Judgeable
K-QueenGiven an N by N board with one white king and K black queens, decide whether the position is check, checkmate, stalemate, or none of these.	Hard8	SortingImplementation+1	No attempts yet	1s	1024 MB	Judgeable
Formula FlatlandGiven a planar road network with crossing coordinates, find the fewest crossings that can form a simple closed cycle.	Hard8	GraphBFS+1	No attempts yet	3s	1024 MB	Judgeable
Foreign FootballGiven the concatenation of every ordered pair of n team names, recover the names and report whether the answer is none, unique, or many.	Hard8	String matchingString+1	No attempts yet	5s	1024 MB	Judgeable
Junk JourneyOutput a move sequence that pushes all n scooters into the depot within 10^5 seconds, where moving into a scooter pushes it along the chain.	Hard8	SimulationImplementation+1	No attempts yet	1s	1024 MB	Judgeable
Keyboard QueriesGiven palindrome facts about substrings of S, decide whether two substrings must be equal, cannot be equal, or remain undetermined.	Hard8	Union-findString matching+1	No attempts yet	1s	1024 MB	Judgeable
GomGom and TetrisTwo players alternately place Tetris pieces or 1x1 blocks on an N by M board to maximize their own score, and the task is to decide the winner with a 0.5 first-player penalty.	Hard8	Game theoryBit manipulation+1	No attempts yet	2s	1024 MB	Judgeable
AND vs ORFor each query range, sum the positive values of (first AND last) minus the OR of the inner elements over all subarrays, modulo 1000000007.	Hard8	Bit manipulationDivide and conquer+1	No attempts yet	2s	1024 MB	Judgeable
Card GameAlice and Bob alternately pick a card on an N by M grid and remove its connected diagonal run by color. Determine whether the first player wins.	Hard8	Game theoryDynamic programming+1	No attempts yet	1s	1024 MB	Judgeable
Empty QuadrilateralsCount simple quadrilaterals on a point set with no three collinear whose interiors contain no other points, for up to 300 points.	Hard8	GeometryDynamic programming+2	No attempts yet	2s	1024 MB	Judgeable
Frog JumpGiven n closed intervals and a sequence of k target intervals, find the total jump length the frog pays while visiting the targets in order from interval 1.	Hard8	IntervalsBinary search+1	No attempts yet	1s	1024 MB	Judgeable
Linear RegressionRemove k points, then find a line that minimizes the largest vertical distance to the remaining points, and print that distance.	Hard8	GeometryBinary search+1	No attempts yet	5s	1024 MB	Judgeable
Longest SubstringFor each k from 1 to n, find the longest substring that occurs exactly k times and allows the most non-overlapping occurrences, then print the lengths.	Hard8	String matchingTree	No attempts yet	5s	1024 MB	Judgeable
SubsetMexGiven the counts f_i of each value below n in a multiset, find the fewest subset-and-mex operations needed to insert n.	Hard8	GreedyDynamic programming+1	No attempts yet	1s	1024 MB	Judgeable
Lego WallCount the connected, hole-free walls of width w and height h built from 1x1x1 and 2x1x1 bricks, modulo 1000000007.	Hard8	CombinatoricsDynamic programming+1	No attempts yet	3s	1024 MB	Judgeable
Take On MemeGiven a rooted vote tree where each child's (x, y) vector is added or subtracted at every node, find the largest squared length the root can reach.	Hard8	TreeGeometry+1	No attempts yet	4s	1024 MB	Judgeable
Unbroken Spirit 2For each prefix of N dragons with growth D_i and start height H_i, find the max total height a thief can cut with one arrow per day.	Hard8	GreedyHeap+1	No attempts yet	1.5s	1024 MB	Judgeable
Unbroken Spirit 3For each k from 1 to N, find the maximum total length the thief can cut from the dragons when shooting at most one arrow per day through day k.	Hard8	Dynamic programmingGreedy+1	No attempts yet	6s	1024 MB	Judgeable
Alternating AlgorithmCount the rounds that odd-even transposition sort needs to fully sort an array of n+1 integers.	Hard8	SortingSimulation+1	No attempts yet	7s	1024 MB	Judgeable
Faster Than LightGiven n non-overlapping axis-aligned rectangles, decide whether a single infinite line touches every one of them.	Hard8	GeometrySorting+1	No attempts yet	10s	1024 MB	Judgeable
Kebab PizzaDecide whether each topping can fill one contiguous circular arc of pizza slices so that each person's slice has exactly their two chosen toppings.	Hard8	GraphImplementation	No attempts yet	3s	1024 MB	Judgeable
MortgageGiven monthly incomes and several loan intervals, find for each interval the largest equal payment that can be covered month by month using only money saved inside that interval.	Hard8	Prefix sumDivide and conquer+1	No attempts yet	3s	1024 MB	Judgeable
Kalel, the Jumping FrogCount the jump sequences that take Kalel from stone 1 to stone N with total energy at most K, modulo 1e9, for jumps of length up to 10.	Hard8	Dynamic programmingMatrix+1	No attempts yet	18s	1024 MB	Judgeable
Silver TreeGiven K, H, and query pairs of keys, find the path length between the two blue nodes holding each pair in a silver tree, or -1 if a key is missing.	Hard8	TreeMath+1	No attempts yet	2s	512 MB	Judgeable
Winter Forest and the Magic FlameGiven a weighted tree rooted at village 1, find the smallest possible farthest distance from the root after shortening edges within a magic budget B, for each query.	Hard8	TreeGreedy+1	No attempts yet	1.5s	512 MB	Judgeable
Expected length of the minimum cycleGiven N and a prime P, find the expected length of the shortest cycle in a random permutation of 1 to N, modulo P as a reduced fraction.	Hard8	CombinatoricsMath	No attempts yet	2s	1024 MB	Judgeable
Flying DoorsGiven n doors with ceiling heights a_i and velocities b_i, arrange them in an order that minimizes the probability Kostya can fly through all doors at a random starting height.	Hard8	SortingGreedy+1	No attempts yet	2s	1024 MB	Judgeable
TicketsGiven a tree of cities and ticket types that reach any city within k train rides for a fixed price, find the cheapest way from each query city to city 1.	Hard8	TreeDivide and conquer+1	No attempts yet	3s	1024 MB	Judgeable
Simple Math ProblemGiven N, K, and X, find the X-th lexicographically smallest length-K array over 1 to N that uses every value and balances each i-1 count around every i.	Hard8	CombinatoricsMath+1	No attempts yet	1s	256 MB	Judgeable
Reimu's Teleportation PracticeGiven a tree where K nodes are priests who can teleport to any priest with equal chance, find the minimum expected moves from A to B.	Hard8	TreeDynamic programming+1	No attempts yet	6s	1024 MB	Judgeable
BinCoinGiven k random signing sequences from a full binary tree, restore each employee's direct superior in that tree.	Hard8	TreeProbability+1	No attempts yet	3s	1024 MB	Judgeable
Cactus Meets TorusGiven a cactus as edge-disjoint paths, decide if it can be drawn on a torus so that cutting along any one cycle keeps the sheet in one piece.	Hard8	GraphDFS+1	No attempts yet	3s	1024 MB	Judgeable
DominoesCount the pairs of free cells that, once both are blocked, leave the grid with no full domino tiling, capped at 1000000.	Hard8	GraphDFS+1	No attempts yet	3s	1024 MB	Judgeable
Game of QuestionsGiven n questions answered correctly or not by m participants, find the probability that participant 1 is the last one left after all questions are asked in a random order.	Hard8	Dynamic programmingBit manipulation+1	No attempts yet	5s	1024 MB	Judgeable
AibohphobiAFind the longest walk from (0, 0) to (M-1, N-1) that visits each query cell and has no palindromic substring, or report -1 or -2.	Hard8	GraphDFS+1	No attempts yet	3s	1024 MB	Judgeable
Balanced Seesaw ArrayGiven an array with range add and range assign updates, answer whether a queried subarray is a balanced seesaw array.	Hard8	Segment treeMath+1	No attempts yet	3s	1024 MB	Judgeable
InvitationCount the groups of k leaders whose availability intervals share a common time slot, for every k from 1 to n, modulo 998244353.	Hard8	CombinatoricsSorting+1	No attempts yet	3s	1024 MB	Judgeable
Under Construction ForeverGiven a connected graph of buildings with costs, find the fewest buildings left after leaf-absorbing reconstructions, the minimum cost for that count, and the number of ways modulo 1,000,000,007.	Hard8	GraphDynamic programming+1	No attempts yet	1s	1024 MB	Judgeable
KnightmareCount the squares attacked by at least k knights, where each knight's reach is a symmetric set of offsets determined by its a and b values.	Hard8	Segment treeSorting+1	No attempts yet	5s	1024 MB	Judgeable
Gold RushCount the distinct win-loss records possible in an n-player single-elimination bracket with best-of-k matches, modulo 1,000,003.	Hard8	Divide and conquerDynamic programming+2	No attempts yet	1s	1024 MB	Judgeable
Knight Moves: Black EditionGiven an N by N board with N up to 1e15, find the fewest knight moves between two cells.	Hard8	MathImplementation	No attempts yet	1s	1024 MB	Judgeable
Who is closerFor each X from 0 to 2^N-1, count the cards Y where X is closer to Z = X xor Y than Y is, with ties won when X < Y.	Hard8	Bit manipulationDivide and conquer+1	No attempts yet	1s	1024 MB	Judgeable
DeCSS 3Given a partially known CSS keystream, find one 42-bit key whose two LFSRs and carry rule reproduce every known byte.	Hard8	BacktrackingBit manipulation+1	No attempts yet	1s	1024 MB	Judgeable
DeCSS 4Given a partially known CSS key stream where unknown bytes are -1, find a 42-bit key that reproduces every known byte.	Hard8	Bit manipulationBrute force+1	No attempts yet	1s	1024 MB	Judgeable
DeCSS 5Given a partly known CSS keystream, find one 42-bit key whose two LFSRs reproduce every known byte.	Hard8	Brute forceMath+1	No attempts yet	1s	1024 MB	Judgeable
DeCSS 6Find one 42-bit key whose two LFSR keystream, combined with a carry, matches all the known bytes in the given sequence.	Hard8	Bit manipulationBrute force+1	No attempts yet	1s	1024 MB	Judgeable
DeCSS 7Given a partly known CSS keystream built from two LFSRs with a carry bit, find any 42-bit key that reproduces the known bytes.	Hard8	Bit manipulationMath+2	No attempts yet	1s	1024 MB	Judgeable
DeCSS 9Given some known bytes of a CSS keystream from two LFSRs (17 and 25 bits) with a carry, find any 42-bit key that reproduces them.	Hard8	Brute forceMath+1	No attempts yet	1s	1024 MB	Judgeable
NeboderiFind the largest product of the GCD and the sum over any contiguous block of at least k skyscrapers, with up to 10^6 heights.	Hard8	Sliding windowNumber theory+1	No attempts yet	2.5s	1024 MB	Judgeable
LampiceCount axis-aligned rectangles with integer corners on an n by m terrace where, for each colour, both lamps are inside or both are outside.	Hard8	Prefix sumDynamic programming+1	No attempts yet	3s	1024 MB	Judgeable
Expected Cycle SizeGiven a permutation pattern where 0 is a wildcard, output for each index the expected cycle size over all random permutations matching the pattern, modulo 998244353.	Hard8	ProbabilityCombinatorics+1	No attempts yet	2s	1024 MB	Judgeable
FoldingGiven a string, count the foldings whose fold positions form an arithmetic set and where every pile holds only one letter.	Hard8	String matchingMath+1	No attempts yet	2s	1024 MB	Judgeable
MFP: Most Fluctuated PlayerGiven Q point updates to N players, find each player's total coins, where coins are the absolute change in point rank after each update.	Hard8	Segment treeSorting+1	No attempts yet	2s	1024 MB	Judgeable
Qarentheziz SequenceGiven a parentheses string with range flips, find for each query the fewest end insertions and adjacent swaps needed to make a substring balanced.	Hard8	Segment treeString+1	No attempts yet	2s	1024 MB	Judgeable
Sequence and Queries 41Given an array, process range updates that set each A_i to max(A_i, x) and queries for the maximum subarray sum inside a range, floored at 0.	Hard8	Segment treeDynamic programming	No attempts yet	5s	1024 MB	Judgeable
PalindromeGiven N numbers with fixed digit lengths, find the fewest elements to replace so their concatenation becomes a palindrome.	Hard8	String matchingTwo pointers+1	No attempts yet	1s	1024 MB	Judgeable
TennisFind the sum of costs over all n-ball sequences whose weight sum mod w is at most x, where cost is the count of balls with weight at most y raised to the power k.	Hard8	Dynamic programmingMath+1	No attempts yet	1s	1024 MB	Judgeable
Quadratic Functions and a LineGiven N quadratics with leading coefficient 1 or -1, pick the fewest that make every line meet at least one of them, and print their indices or -1.	Hard8	GeometryMath+1	No attempts yet	0.1s	1024 MB	Judgeable
Maximum Absolute Value of the Product of Interval SumsGiven an integer array and at most K non-overlapping intervals, find the maximum absolute value of the product of the interval sums.	Hard8	Dynamic programmingPrefix sum+1	No attempts yet	1s	256 MB	Judgeable
Stone Game and QueriesGiven X, T, and N, find the fewest turns needed to leave the fewest stones, where turn I takes a multiple of X+I of at most (X+I)×T stones.	Hard8	Number theoryMath+1	No attempts yet	1.5s	512 MB	Judgeable
Card GamePlayers alternately discard the opponent's decks, and given the known win and loss pairs, the task is to decide whether Bajtek wins, draws, or loses.	Hard8	Game theoryGraph+1	No attempts yet	2s	1024 MB	Judgeable
Hilbert BilliardsGiven a ball bouncing inside a Hilbert-curve billiard table of size 2n+1, report its integer coordinates at up to 100000 query times.	Hard8	SimulationMath+1	No attempts yet	2s	1024 MB	Judgeable
PermutationFind the k-th lexicographically smallest permutation of length n whose inversion count is exactly half of all pairs, or report NIE if none exists.	Hard8	CombinatoricsMath+1	No attempts yet	1s	1024 MB	Judgeable
CarcassonneCounts the distinct sets of k new tiles that can be added to an n by n board so each new tile touches the tiles placed before it, modulo 1e9+7.	Hard8	MatrixBFS+1	No attempts yet	5s	1024 MB	Judgeable
Magic TowersGiven n mages with two towers each, find the area of points where every movement direction brings you closer to both towers of some mage.	Hard8	GeometryMath	No attempts yet	1s	1024 MB	Judgeable
Alps Cable Car 2Connect the peaks of N triangles from peak 1 to peak N using at most K wires, minimizing the sum of squared wire lengths.	Hard8	Dynamic programmingGeometry+1	No attempts yet	2s	1024 MB	Judgeable
Babel TowerGiven barbell weights for N exercises in order, find the plate moves with the smallest total moved weight, breaking ties by fewest plates moved.	Hard8	StackGreedy+1	No attempts yet	1s	1024 MB	Judgeable
Sotteok-Sotteok 2Remove some foods, then pick one vertical line so the foods it crosses, sorted by height, alternate sausage and rice cake with the maximum total length.	Hard8	Segment treeDynamic programming+1	No attempts yet	2s	1024 MB	Judgeable
TeaDecide whether splitting and mixing tea can turn each cup's initial temperature into its target temperature while keeping every volume.	Hard8	MathSorting+1	No attempts yet	8s	1024 MB	Judgeable
Concurrent ProgrammingGiven n programs that read, write, and add or subtract on a shared variable, find the smallest final value of x over all interleavings.	Hard8	GreedySimulation+2	No attempts yet	9s	1024 MB	Judgeable
Three RoadsCount the triples of roads whose removal leaves some pair of cities unable to reach each other in a connected graph.	Hard8	GraphDFS+1	No attempts yet	8s	1024 MB	Judgeable
ExhibitionPick Anna's or Bogusław's painting each week so exactly k are Anna's, minimizing the maximum subarray sum of the hung values.	Hard8	Dynamic programmingBinary search+1	No attempts yet	9s	1024 MB	Judgeable
Online Shop RankingFind the maximum of length plus twice the median over all contiguous subarrays of a permutation, and count the subarrays that reach it.	Hard8	ArrayPrefix sum+1	No attempts yet	2s	1024 MB	Judgeable
Vials 2Given a directed acyclic graph of vials and k chemicals in the first k vials, count intervals [l, r] above k by the maximum number of chemicals that can be moved into them.	Hard8	GraphTwo pointers+1	No attempts yet	10s	1024 MB	Judgeable
RaisesSplit a sequence into k contiguous segments so that no strictly increasing sequence picks one element from each segment, or report that no such split exists.	Hard8	Dynamic programmingGreedy+1	No attempts yet	2s	1024 MB	Judgeable
Bajtessi's DribblingFor each pair of dribbles, count the distinct balanced, left-sided subsequences of their concatenation, modulo 1e9+7.	Hard8	Dynamic programmingString+1	No attempts yet	9s	1024 MB	Judgeable
Spanning TreesCount the spanning trees of a graph where each pair of vertices i and j has gcd(a_i, a_j) parallel edges, modulo 10^9+7.	Hard8	Number theoryGraph+1	No attempts yet	8s	1024 MB	Judgeable
Tightrope WalkingGiven a permutation, for each rope find the sum of minimum crossing-switch counts to reach every other rope, where two ropes can switch only if they cross.	Hard8	GraphBFS+1	No attempts yet	6s	1024 MB	Judgeable
Bracket PartitionsSplit a bracket string of length n into k contiguous parts so that the total number of correct bracket substrings across all parts is as small as possible.	Hard8	Dynamic programmingBinary search+1	No attempts yet	7s	1024 MB	Judgeable
AgentsGiven a tree with k agents at fixed start cities, find the fewest days for the agents to visit every city, with each city visited by one agent only.	Hard8	TreeBinary search+2	No attempts yet	3s	1024 MB	Judgeable
ParenthesesGiven a permutation p of n cards, assign each card an opening or closing bracket so both the original and shuffled orders are correct bracket sequences.	Hard8	GraphGreedy+1	No attempts yet	4s	1024 MB	Judgeable
Gang of BiciaksGiven a tree with colored edges, answer how many distinct colors lie on the path from root 1 to a query node, while edge colors change over time.	Hard8	TreeDivide and conquer+1	No attempts yet	12s	1024 MB	Judgeable
KindergartenCount the proper k-colorings of a graph with n vertices and m edges, for up to 1000 values of k, modulo 1000000007.	Hard8	GraphCombinatorics+1	No attempts yet	2s	1024 MB	Judgeable