Problems

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Total results29,214 problems

Magic Orbs
Hard8
Array, Simulation+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Romantic Cat
Hard8
Sorting, Hash map+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Seongho and Dusan
Hard8
Tree, Greedy+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Ninja Delivery
Hard8
Tree, Divide and conquer+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Minimum Spanning Arborescence
Hard8
Minimum spanning tree, Graph+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Han Yo-won's Infiltration
Hard8
Greedy, Dynamic programming+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Erased ETT
Hard8
Dynamic programming, Tree+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Tutrili and Queries
Hard8
Tree, DFS+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Where to Go?
Hard8
Graph, Shortest path+1
No attempts yet
Time limit
2.5s
Memory limit
1024 MB
Judgeable
Events Are Approaching (Hard)
Hard8
Dynamic programming, Intervals+1
No attempts yet
Time limit
4s
Memory limit
1024 MB
Judgeable
Union of Segments
Hard8
Dynamic programming, Sorting+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Cocoa and the Wizard's Stone
Hard8
Tree, Divide and conquer+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Rail Restoration at Songdo High School
Hard8
Simulation, Segment tree+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
What Happens When All the Branches Fall From a Tree?
Hard8
Tree, Game theory+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
What if Jaewoo, who cannot eat spicy food, eats bibim naengmyeon?
Hard8
Probability, Math+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
At Last, Coprime
Hard8
Math, Number theory+1
No attempts yet
Time limit
5s
Memory limit
1024 MB
Judgeable
Equal remainders
Hard8
Number theory, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Board Game
Hard8
Game theory, Segment tree+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Water the Tree
Hard8
Tree, DFS+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Weight Copy Bug
Hard8
Shortest path, Graph+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Natural Number Streamer
Hard8
String, String matching+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Zigzag Histogram Partition
Hard8
Dynamic programming, Segment tree+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Treasure
Hard8
Implementation, Math+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Message
Hard8
Bit manipulation, Math+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Nile
Hard8
Dynamic programming, Sorting+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Hieroglyphs
Hard8
Dynamic programming, Greedy+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Mosaic
Hard8
Dynamic programming, Prefix sum+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Sphinx's Riddle
Hard8
Graph, Divide and conquer+1
No attempts yet
Time limit
1.5s
Memory limit
1024 MB
Judgeable
Red and Blue Dots 2
Hard8
Dynamic programming, Geometry+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Square Game
Hard8
Divide and conquer, Greedy+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
정다각형을 만들어요
Hard8
Dynamic programming, Tree+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Make the remainder
Hard8
Math, Number theory+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Copogonia
Hard8
Bit manipulation, Shortest path+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Password Protection
Hard8
String matching, Combinatorics+1
No attempts yet
Time limit
8s
Memory limit
1024 MB
Judgeable
Snake Game
Hard8
Graph, Simulation+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Swipe
Hard8
Array, Greedy+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Life
Hard8
Dynamic programming, Greedy
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Telephone Plans
Hard8
Segment tree, Union-find+1
No attempts yet
Time limit
4s
Memory limit
1024 MB
Judgeable
Bingo for the Win!
Hard8
Probability, Combinatorics+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Tower of noiHa
Hard8
Bit manipulation, Recursion+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Geography of Rivers
Hard8
Tree, Segment tree+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Circle Passing
Hard8
Graph, Shortest path+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Lexicopolis
Hard8
Graph, Dynamic programming+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Mosaic
Hard8
Array, Implementation+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Piece Game
Hard8
Game theory, Segment tree+1
No attempts yet
Time limit
1.5s
Memory limit
1024 MB
Judgeable
LEX_GCD
Hard8
Number theory, Greedy+1
No attempts yet
Time limit
1.5s
Memory limit
1024 MB
Judgeable
Aquarelle
Hard8
Dynamic programming, Intervals+1
No attempts yet
Time limit
0.4s
Memory limit
1024 MB
Judgeable
Balatro
Hard8
Dynamic programming, Sorting+2
No attempts yet
Time limit
12s
Memory limit
1024 MB
Judgeable
Job Scheduling
Hard8
Intervals, Dynamic programming+2
No attempts yet
Time limit
4s
Memory limit
1024 MB
Judgeable
Fractal Area
Hard8
Geometry, Math+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Double Deck
Hard8
Dynamic programming, Bit manipulation+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Eradication Sort
Hard8
Dynamic programming, Segment tree+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Jabber Network
Hard8
Tree, DFS+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Pigpartite Giraffe
Hard8
Bit manipulation, Graph+1
No attempts yet
Time limit
5s
Memory limit
1024 MB
Judgeable
Curious Jury
Hard8
Combinatorics, Prefix sum+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Operation
Hard8
Segment tree, Binary search+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Geunsoo's Maze Game
Hard8
Game theory, Graph+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Panel Optimization (Easy)
Hard8
Graph, Dynamic programming+1
No attempts yet
Time limit
4s
Memory limit
1024 MB
Judgeable
Panel Optimization (Hard)
Hard8
Graph, Matrix
No attempts yet
Time limit
4s
Memory limit
1024 MB
Judgeable
Repeating Number
Hard8
Math, Number theory+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Marks
Hard8
Combinatorics, Number theory+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Knight Polygon
Hard8
Geometry, Math+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Tree With One Edge
Hard8
Tree, Game theory+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Ring Out
Hard8
Probability, Combinatorics+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Colored Rectangles and Queries
Hard8
Geometry, Segment tree+1
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Gahui and Music
Hard8
Dynamic programming, Prefix sum+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Champernowne Subsequence
Hard8
String, Greedy+2
No attempts yet
Time limit
2s
Memory limit
2048 MB
Judgeable
Free Solo
Hard8
Geometry, Graph+1
No attempts yet
Time limit
5s
Memory limit
2048 MB
Judgeable
Fences Make Good Neighbors
Hard8
Dynamic programming, Geometry
No attempts yet
Time limit
4s
Memory limit
2048 MB
Judgeable
Protecting Kingdom
Hard8
Tree, Divide and conquer+2
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
String Rank
Hard8
String, Greedy+1
No attempts yet
Time limit
0.5s
Memory limit
2048 MB
Judgeable
Great Plain
Hard8
Shortest path, Graph+2
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Add One Zero-Weight Edge to Minimize the Sum of Root Distances
Hard8
Tree, DFS+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Blistavost
Hard8
Dynamic programming, Intervals+1
No attempts yet
Time limit
4s
Memory limit
1024 MB
Judgeable
K Subway Stations
Hard8
Tree, Binary search+2
No attempts yet
Time limit
1.5s
Memory limit
1024 MB
Judgeable
Binary Search
Hard8
Graph, Dynamic programming+1
No attempts yet
Time limit
4s
Memory limit
1024 MB
Judgeable
Glued Grid
Hard8
Math, Graph+1
No attempts yet
Time limit
3s
Memory limit
2048 MB
Judgeable
It's a Kind of Magic
Hard8
Number theory, Combinatorics+1
No attempts yet
Time limit
4s
Memory limit
2048 MB
Judgeable
Capybara Cozy Carnival
Hard8
Math, Graph+1
No attempts yet
Time limit
4s
Memory limit
2048 MB
Judgeable
Recurrence and Queries
Hard8
Math, Matrix+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Heavy Rain
Hard8
Segment tree, Array+1
No attempts yet
Time limit
5s
Memory limit
1024 MB
Judgeable
Stablo
Hard8
Tree, DFS+1
No attempts yet
Time limit
2s
Memory limit
2048 MB
Judgeable
Candles and shadows 2
Hard8
Geometry, Greedy+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
I Am Not an Anime Enthusiast
Hard8
Segment tree, Divide and conquer+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Accumulator Apex
Hard8
Greedy, Dynamic programming+1
No attempts yet
Time limit
3s
Memory limit
2048 MB
Judgeable
Legacy Screensaver
Hard8
Math, Number theory+1
No attempts yet
Time limit
3s
Memory limit
2048 MB
Judgeable
East 2 Will Not Come to This Match! 9
Hard8
Combinatorics, Dynamic programming+1
No attempts yet
Time limit
5s
Memory limit
1024 MB
Judgeable
Interstellar Intervals
Hard8
Dynamic programming, String matching
No attempts yet
Time limit
2s
Memory limit
2048 MB
Judgeable
2D conveyor belt
Hard8
Matrix, Graph+1
No attempts yet
Time limit
2s
Memory limit
2048 MB
Judgeable
Lighting
Hard8
Geometry, Two pointers+1
No attempts yet
Time limit
4s
Memory limit
1024 MB
Judgeable
Robot Upgrades
Hard8
Dynamic programming, Combinatorics+1
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Sorting Machine
Hard8
String, Sorting+2
No attempts yet
Time limit
1.5s
Memory limit
2048 MB
Judgeable
Independent Set (Max)
Hard8
Tree, Dynamic programming+1
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Intensive Training
Hard8
Math, Greedy+1
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Primal Collection
Hard8
Combinatorics, Tree+1
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Narrower Passageway
Hard8
Stack, Probability+2
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable
Heraclosures
Hard8
Dynamic programming, Graph+1
No attempts yet
Time limit
5.5s
Memory limit
2048 MB
Judgeable
Flowers
Hard8
Game theory, Tree+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Intimate Chef
Hard8
Sorting, Heap+1
No attempts yet
Time limit
3s
Memory limit
2048 MB
Judgeable
Moderation in all things
Hard8
Linked list, Tree+1
No attempts yet
Time limit
1s
Memory limit
2048 MB
Judgeable

Title	Level	Topics	Solved	Time limit	Memory limit	Judge
Magic OrbsOrbs dropped on zone 1 roll right past strictly lower zones and raise the zone where they stop; report zone 1's value after each batch.	Hard8	ArraySimulation+1	No attempts yet	1s	1024 MB	Judgeable
Romantic CatSum the areas of axis-parallel squares whose four corners are stars and whose whole boundary has only one color, modulo 1e9+7.	Hard8	SortingHash map+1	No attempts yet	3s	1024 MB	Judgeable
Seongho and DusanPlayers alternately remove leaves from their own trees, and the removed marble's color picks the next player. Find the min and max marbles left at the end.	Hard8	TreeGreedy+1	No attempts yet	1s	1024 MB	Judgeable
Ninja DeliveryPick hubs x and y on a tree to minimize the total weighted cost of Q requests, where each request goes from a to x, x to y, then y to b.	Hard8	TreeDivide and conquer+2	No attempts yet	1s	1024 MB	Judgeable
Minimum Spanning ArborescenceFind the minimum total weight of a spanning arborescence rooted at r in a directed weighted graph, or report -1 if none exists.	Hard8	Minimum spanning treeGraph+2	No attempts yet	2s	1024 MB	Judgeable
Han Yo-won's InfiltrationPick quiet, noisy, or teleport for each passage, with at most W noisy passes and T teleports, to find the minimum total time from building 1 to N+1.	Hard8	GreedyDynamic programming+1	No attempts yet	1s	1024 MB	Judgeable
Erased ETTCount the ways to replace each 0 with a vertex from 1 to n so the array becomes a valid DFS entry and exit sequence of a tree rooted at 1.	Hard8	Dynamic programmingTree+1	No attempts yet	1s	1024 MB	Judgeable
Tutrili and QueriesEach edge of tree T is replaced by a copy of T attached through the pair (c_i, d_i). Print the distance between two given vertices of the result.	Hard8	TreeDFS+1	No attempts yet	2s	1024 MB	Judgeable
Where to Go?Given a graph with vertex scores and a bonus every R-th move, find the maximum score from walks of at most K moves starting anywhere.	Hard8	GraphShortest path+1	No attempts yet	2.5s	1024 MB	Judgeable
Events Are Approaching (Hard)Given N timed events that forbid positions strictly between A and B at each time T, find the minimum total distance Minjeong moves to dodge them all, or -1 if impossible.	Hard8	Dynamic programmingIntervals+1	No attempts yet	4s	1024 MB	Judgeable
Union of SegmentsGiven N segments with prices and lengths, answer Q queries: can a subset with total price A have a union length of exactly B?	Hard8	Dynamic programmingSorting+1	No attempts yet	1s	1024 MB	Judgeable
Cocoa and the Wizard's StoneGiven a tree of N vertices, add at most floor(N/5) edges so that the graph's diameter is at most 10.	Hard8	TreeDivide and conquer+2	No attempts yet	1s	1024 MB	Judgeable
Rail Restoration at Songdo High SchoolFor each rail, find the rail where an object placed at its start ends up after repeatedly switching to crossing rails with smaller priority.	Hard8	SimulationSegment tree+1	No attempts yet	1s	1024 MB	Judgeable
What Happens When All the Branches Fall From a Tree?Two players take turns removing a root-to-vertex path from a tree, and a Nim game on the removed stones decides each turn. The task is to find the winner.	Hard8	TreeGame theory+2	No attempts yet	1s	1024 MB	Judgeable
What if Jaewoo, who cannot eat spicy food, eats bibim naengmyeon?Find the probability that after K random picks of member ingredient sets, every ingredient total is a multiple of its S_i.	Hard8	ProbabilityMath+2	No attempts yet	1s	1024 MB	Judgeable
At Last, CoprimeGiven N up to 10^11, sum i+j over all pairs (i, j) with 1 to N that are coprime, and output the result modulo 10^9+7.	Hard8	MathNumber theory+1	No attempts yet	5s	1024 MB	Judgeable
Equal remaindersGiven N distinct integers A and a value K, find the smallest positive M so that s^K lies in S(A^M) for every s in S(A), modulo 1e9+7, or -1.	Hard8	Number theoryMath	No attempts yet	1s	1024 MB	Judgeable
Board GameGiven two N by M grids of A and B cards, find who wins the alternating column-removal game at the start and after each of Q card swaps.	Hard8	Game theorySegment tree+2	No attempts yet	1s	1024 MB	Judgeable
Water the TreeGiven a rooted tree with fruit sizes, process queries that pour water into a vertex and flow it down to children, and report a fruit's current size.	Hard8	TreeDFS+1	No attempts yet	2s	1024 MB	Judgeable
Weight Copy BugFind the shortest path from s to e in a graph with 0/1 edge weights where each traversed edge raises all later edge weights by its current weight, and print the answer in binary.	Hard8	Shortest pathGraph+1	No attempts yet	2s	1024 MB	Judgeable
Natural Number StreamerGiven a binary string, find the longest substring that is the concatenation of consecutive binary numbers starting from some l.	Hard8	StringString matching+1	No attempts yet	3s	1024 MB	Judgeable
Zigzag Histogram PartitionSplit a histogram of N bars into contiguous pieces so that each piece's largest rectangle forms a zigzag sequence, maximizing the number of pieces.	Hard8	Dynamic programmingSegment tree+1	No attempts yet	1s	1024 MB	Judgeable
TreasureEncode N distinct 2D integer points as a shuffled multiset of non-negative integers up to 2e9 using as few numbers as possible, then decode them.	Hard8	ImplementationMath+1	No attempts yet	3s	1024 MB	Judgeable
MessageAisha must send a bit message through 31-bit packets where Cleopatra flips 15 hidden positions, and Basma must recover the message from the tainted packets.	Hard8	Bit manipulationMath+1	No attempts yet	3s	1024 MB	Judgeable
NileFor each query D, find the minimum cost to ship all artifacts when two artifacts share a boat only if their weights differ by at most D.	Hard8	Dynamic programmingSorting+1	No attempts yet	2s	1024 MB	Judgeable
HieroglyphsFind the universal common subsequence of two integer sequences A and B, or report that none exists.	Hard8	Dynamic programmingGreedy+1	No attempts yet	1s	1024 MB	Judgeable
MosaicGiven the top row and left column of an N by N grid filled by a NOR rule, answer Q queries counting black tiles in given subrectangles.	Hard8	Dynamic programmingPrefix sum+1	No attempts yet	1s	1024 MB	Judgeable
Sphinx's RiddleFind the hidden colour of each vertex in a connected graph using at most 2750 experiments, each returning the number of monochromatic components.	Hard8	GraphDivide and conquer+1	No attempts yet	1.5s	1024 MB	Judgeable
Red and Blue Dots 2Given N points on a circle, each red or blue, find the fewest crossing pairs among same-color chords that touch every point at least once.	Hard8	Dynamic programmingGeometry+1	No attempts yet	1s	1024 MB	Judgeable
Square GameFor each query range of a sequence, find the maximum number of square operations that replace k copies of k with one k squared.	Hard8	Divide and conquerGreedy+1	No attempts yet	1s	1024 MB	Judgeable
정다각형을 만들어요Count vertex sets of size 2 or more in a tree where exactly one vertex is equidistant from every chosen vertex, modulo 10^9+7.	Hard8	Dynamic programmingTree+2	No attempts yet	2s	1024 MB	Judgeable
Make the remainderFind hidden N and M by querying X and receiving the distance from N to its nearest multiple of X, taken mod M, using at most 100 queries.	Hard8	MathNumber theory+1	No attempts yet	1s	1024 MB	Judgeable
CopogoniaGiven a convex polygon of n cities and up to k candidate chords with costs, choose a cheapest subset so every pair of cities has shortest route length at most m.	Hard8	Bit manipulationShortest path+2	No attempts yet	2s	1024 MB	Judgeable
Password ProtectionCount length-n lowercase strings that contain the first name or the last name as a contiguous substring, modulo 1,000,000,007.	Hard8	String matchingCombinatorics+1	No attempts yet	8s	1024 MB	Judgeable
Snake GameFind the maximum length a snake can reach on an arrow grid, where apples change its path and the game ends when the head hits its body or the wall.	Hard8	GraphSimulation+1	No attempts yet	1s	1024 MB	Judgeable
SwipeGiven arrays A and B, decide whether repeated left and right range swipes can turn A into B, and output a valid swipe sequence if so.	Hard8	ArrayGreedy+1	No attempts yet	1s	1024 MB	Judgeable
LifeFor each prefix of length n, find the minimum total of chosen values when each pick shifts all later A and B values by +U or -D.	Hard8	Dynamic programmingGreedy	No attempts yet	2s	1024 MB	Judgeable
Telephone PlansGiven a forest where phone lines are added and removed over time, count the pairs of houses connected in at least one network state from the last t queries.	Hard8	Segment treeUnion-find+1	No attempts yet	4s	1024 MB	Judgeable
Bingo for the Win!Given each player's bingo sheet and a uniformly random calling order, find the probability that each player is the last to finish under Speed Bingo rules.	Hard8	ProbabilityCombinatorics+2	No attempts yet	1s	1024 MB	Judgeable
Tower of noiHaGiven n disks and k optimal Hanoi moves already made, find the fewest valid moves to finish after the son moves the whole stack in one move. Both k and the answer are binary.	Hard8	Bit manipulationRecursion+1	No attempts yet	1s	1024 MB	Judgeable
Geography of RiversGiven a merge tree of river sources, report after each rain update which source name the final river carries into the sea.	Hard8	TreeSegment tree+1	No attempts yet	2s	1024 MB	Judgeable
Circle PassingGiven 2N students in a circle with best-friend pairs placed directly opposite each other, find the fewest passes needed to move the ball from student x to student y for each query.	Hard8	GraphShortest path+1	No attempts yet	2s	1024 MB	Judgeable
LexicopolisFind the lexicographically smallest walk of exactly k edges from s to t, comparing edge magic numbers, and output its polynomial value modulo 1e9+7.	Hard8	GraphDynamic programming+1	No attempts yet	2s	1024 MB	Judgeable
MosaicGiven an R-by-C matrix where each cell holds the count of black squares in its 3x3 neighborhood, rebuild a black and white grid that produces it, or report that none exists.	Hard8	ArrayImplementation+1	No attempts yet	2s	1024 MB	Judgeable
Piece GameGiven an integer array with distinct values and a move limit D, answer whether the first player wins a piece game under optimal play, with point updates to the array.	Hard8	Game theorySegment tree+1	No attempts yet	1.5s	1024 MB	Judgeable
LEX_GCDFind the lexicographically smallest permutation that is K-gcd equivalent to a sequence, after optionally multiplying one element by a prime X.	Hard8	Number theoryGreedy+1	No attempts yet	1.5s	1024 MB	Judgeable
AquarelleGiven color sets for N cells and an initial painted range l to r, decide if the rest can be painted so each new cell adds an unseen color.	Hard8	Dynamic programmingIntervals+1	No attempts yet	0.4s	1024 MB	Judgeable
BalatroPick a subsequence of add and multiply cards, using at most k multiply cards, to maximize the final score for each length up to n.	Hard8	Dynamic programmingSorting+2	No attempts yet	12s	1024 MB	Judgeable
Job SchedulingGiven N base jobs and Q queries that each add R jobs, find the maximum number of non-overlapping jobs after each query's additions.	Hard8	IntervalsDynamic programming+2	No attempts yet	4s	1024 MB	Judgeable
Fractal AreaGiven a generator polyline from (0,0) to (1,0), compute the area of the fractal built by recursively replacing each side of an equilateral triangle with scaled copies of it.	Hard8	GeometryMath+1	No attempts yet	1s	1024 MB	Judgeable
Double DeckFind the maximum number of matched pairs between two decks of N*K cards, where each mismatch discards the top card of one deck.	Hard8	Dynamic programmingBit manipulation+1	No attempts yet	2s	1024 MB	Judgeable
Eradication SortRemove climbers so the rest form a non-decreasing sequence, minimizing the sum of squared lengths of the gaps left behind.	Hard8	Dynamic programmingSegment tree+1	No attempts yet	2s	1024 MB	Judgeable
Jabber NetworkFor each cable in input order, remove it and add the new cable that minimizes total weighted distance between communicating pairs, breaking ties by smallest pair.	Hard8	TreeDFS+2	No attempts yet	2s	1024 MB	Judgeable
Pigpartite GiraffeAfter each birth, print the sum of shortest-path distances over all animal pairs, where each newborn links to animals that like exactly one of its parents.	Hard8	Bit manipulationGraph+1	No attempts yet	5s	1024 MB	Judgeable
Curious JurySum the number of fixed points (rank equals penalty) over all 2^n ways to pick each team's last-submit or sum-of-submits penalty, modulo 1e9+7.	Hard8	CombinatoricsPrefix sum+1	No attempts yet	3s	1024 MB	Judgeable
OperationStarting from one cell, you capture adjacent cells whose energy requirement you meet, and each capture raises your energy by k. Find the most cells you can capture from any start.	Hard8	Segment treeBinary search+1	No attempts yet	1s	1024 MB	Judgeable
Geunsoo's Maze GameGeunsoo walks a grid maze while Seunghyeong blocks one direction each turn; find the fewest turns to a goal under optimal play, or -1 if he cannot win.	Hard8	Game theoryGraph+1	No attempts yet	2s	1024 MB	Judgeable
Panel Optimization (Easy)Given an N by N grid of voltages with adjustment costs, assign each cell a positive, zero, or negative sign to maximize the energy from adjacent pairs minus the adjustment costs.	Hard8	GraphDynamic programming+1	No attempts yet	4s	1024 MB	Judgeable
Panel Optimization (Hard)Given an N by N grid of voltages and per-cell adjustment costs, find the maximum energy from adjacent sign pairs after changing the voltages.	Hard8	GraphMatrix	No attempts yet	4s	1024 MB	Judgeable
Repeating NumberCount the K-repeating numbers in [A, B] that are divisible by M, where a K-repeating number is a periodic prefix of a repeated K-digit block.	Hard8	MathNumber theory+1	No attempts yet	1s	1024 MB	Judgeable
MarksFor each round with W and B, count the marks with an odd number of white squares and those with an even number, then print the winner and the difference modulo 1234543.	Hard8	CombinatoricsNumber theory+1	No attempts yet	1s	512 MB	Judgeable
Knight PolygonGiven integers p and q, find a simple lattice polygon whose edges are all knight moves and whose area is p/q, or print -1 if none exists.	Hard8	GeometryMath+1	No attempts yet	1s	1024 MB	Judgeable
Tree With One EdgeGiven a rooted tree, count the directed pairs (u, v) where adding one edge u to v lets Alice win the token game where players move token down to children.	Hard8	TreeGame theory+1	No attempts yet	1s	1024 MB	Judgeable
Ring OutFor each staff member, sum over rounds the probability that two or more of their balls come out consecutively when all balls in the round's range are shuffled and drawn.	Hard8	ProbabilityCombinatorics+2	No attempts yet	1s	1024 MB	Judgeable
Colored Rectangles and QueriesGiven N non-touching axis-aligned rectangles with colored sides, answer each query with the fewest distinct side colors that any path between two points must pass through.	Hard8	GeometrySegment tree+1	No attempts yet	3s	512 MB	Judgeable
Gahui and MusicGiven n measures with satisfaction values and optional Segno or Dal Segno marks, find the maximum total satisfaction when at most two marks are placed and no part repeats three or more times.	Hard8	Dynamic programmingPrefix sum+1	No attempts yet	1s	512 MB	Judgeable
Champernowne SubsequenceGiven a digit string, find the smallest k such that the string is a subsequence of the Champernowne word formed by concatenating 1 through k.	Hard8	StringGreedy+2	No attempts yet	2s	2048 MB	Judgeable
Free SoloFind the shortest path Alex's body point can travel while keeping at least three of four limbs on holds, until a limb touches the target hold.	Hard8	GeometryGraph+1	No attempts yet	5s	2048 MB	Judgeable
Fences Make Good NeighborsTriangulate a convex polygon so that exactly two fences separate the two brothers' parcels, avoiding fences through their houses, and minimize total fence length.	Hard8	Dynamic programmingGeometry	No attempts yet	4s	2048 MB	Judgeable
Protecting KingdomGiven a tree whose edges hold hazardous points, find the most points one shortest path of length at most w can cover between two points on the roads.	Hard8	TreeDivide and conquer+2	No attempts yet	1s	2048 MB	Judgeable
String RankGiven a string w of length up to 3 times 10^6, find the smallest t such that all suffixes of w have pairwise different sets of subsequences of length at most t.	Hard8	StringGreedy+1	No attempts yet	0.5s	2048 MB	Judgeable
Great PlainGiven axis-parallel rectangles with per-km travel costs, find the least time for an ant to move from the start point to the destination.	Hard8	Shortest pathGraph+2	No attempts yet	3s	1024 MB	Judgeable
Add One Zero-Weight Edge to Minimize the Sum of Root DistancesGiven a weighted tree rooted at vertex 1, add one zero-weight edge to minimize the sum of root distances and print that minimum.	Hard8	TreeDFS+1	No attempts yet	2s	1024 MB	Judgeable
BlistavostFind the minimum time for a walker starting at position 0 on a line to touch every crystal in the requested ranges no earlier than each range's bedtime.	Hard8	Dynamic programmingIntervals+1	No attempts yet	4s	1024 MB	Judgeable
K Subway StationsGiven a weighted tree, choose a path of at most K nodes that minimizes the maximum distance from any node to the path.	Hard8	TreeBinary search+2	No attempts yet	1.5s	1024 MB	Judgeable
Binary SearchGiven an undirected graph with 0/1 labels on vertices, find the length of the shortest binary string that no walk can spell, or report infinity.	Hard8	GraphDynamic programming+1	No attempts yet	4s	1024 MB	Judgeable
Glued GridDecide whether a sliding puzzle with glued tiles can be sorted into row-major order with the empty square at the bottom right.	Hard8	MathGraph+1	No attempts yet	3s	2048 MB	Judgeable
It's a Kind of MagicCount the 3x3 grids of positive integers whose row, column, and diagonal products are all equal and at most n, for up to 1e5 values of n.	Hard8	Number theoryCombinatorics+1	No attempts yet	4s	2048 MB	Judgeable
Capybara Cozy CarnivalCount proper k-colorings of an n-corner polygon's vertices, where sides and non-crossing diagonals are edges, modulo 998244353.	Hard8	MathGraph+1	No attempts yet	4s	2048 MB	Judgeable
Recurrence and QueriesGiven x_n = ax_(n-1) + bx_(n-2) + n^k with initial terms x_0 and x_1, answer up to 50,000 queries for x_n mod 100003 where n is up to 10^18.	Hard8	MathMatrix+1	No attempts yet	3s	1024 MB	Judgeable
Heavy RainGiven N wall heights and range-assign queries, report the maximum rain trapped between the walls after each query.	Hard8	Segment treeArray+1	No attempts yet	5s	1024 MB	Judgeable
StabloGiven a rooted tree with node values, answer queries that temporarily move node x between y and its descendant, then report the weighted distance sum f(y) over y's subtree.	Hard8	TreeDFS+1	No attempts yet	2s	2048 MB	Judgeable
Candles and shadows 2Find the fewest points in the ring between a convex red polygon and a blue polygon inside it, so every point of the ring is visible from a candle.	Hard8	GeometryGreedy+1	No attempts yet	2s	1024 MB	Judgeable
I Am Not an Anime EnthusiastFor each day prefix, count the anime that at least C distinct friends have watched, given range-watch records where friends may rewatch.	Hard8	Segment treeDivide and conquer+1	No attempts yet	2s	1024 MB	Judgeable
Accumulator ApexGiven a starting value x and k lists, take elements from the front of each list and add them to x, keeping x non-negative, to maximize the final x.	Hard8	GreedyDynamic programming+1	No attempts yet	3s	2048 MB	Judgeable
Legacy ScreensaverTwo bouncing rectangles move around a W by H screen; find the long-run fraction of seconds in which their interiors overlap.	Hard8	MathNumber theory+1	No attempts yet	3s	2048 MB	Judgeable
East 2 Will Not Come to This Match! 9Count the ways to pick 14 of the N wall tiles, by position, that can form a dragon of one head and four bodies or seven distinct heads, modulo 998244353.	Hard8	CombinatoricsDynamic programming+1	No attempts yet	5s	1024 MB	Judgeable
Interstellar IntervalsCount the colorings of N points that match an R, B, X pattern, where each coloring is built from disjoint blocks of x red points followed by x blue points.	Hard8	Dynamic programmingString matching	No attempts yet	2s	2048 MB	Judgeable
2D conveyor beltEach day a belt is placed on an empty cell of an N by N grid; after each day, report the fewest cells that can still trap items inside the grid forever.	Hard8	MatrixGraph+1	No attempts yet	2s	2048 MB	Judgeable
LightingGiven a zigzag road built from segments of lengths a_i, find the fewest line segments that describe the light trace as Rabbit Math walks along the road.	Hard8	GeometryTwo pointers+1	No attempts yet	4s	1024 MB	Judgeable
Robot UpgradesCount the ways to set each of N parts to an upgrade level from 0 to M so that, for each i, at most A_i parts reach level i or higher, modulo 998244353.	Hard8	Dynamic programmingCombinatorics+1	No attempts yet	1s	2048 MB	Judgeable
Sorting MachineGiven N equal-length texts, each query asks for the sorted position of text X among texts A to B, after keeping only columns L to R and sorting stably.	Hard8	StringSorting+2	No attempts yet	1.5s	2048 MB	Judgeable
Independent Set (Max)Given a tree, find the maximum of (set size) times (minimum edges connecting the set) over all non-empty sets of pairwise non-adjacent nodes.	Hard8	TreeDynamic programming+1	No attempts yet	1s	2048 MB	Judgeable
Intensive TrainingGiven N days, find the maximum sum of k_i times r_i, where k is nonincreasing, r is nondecreasing, sum of k is K, and sum of r is R.	Hard8	MathGreedy+1	No attempts yet	1s	2048 MB	Judgeable
Primal CollectionCount the primal arrays over values 1 to N+1 (missing S) for which inserting S at position N+1 and sifting it up takes exactly K swaps.	Hard8	CombinatoricsTree+1	No attempts yet	1s	2048 MB	Judgeable
Narrower PassagewayEach column is fogged with probability 1/2; find the expected total strength, where each unfogged segment adds min of its two row maxima (0 if equal), modulo 998244353.	Hard8	StackProbability+2	No attempts yet	1s	2048 MB	Judgeable
HeraclosuresFunctions form a call DAG with base times and point updates; answer each query for total time T(i) and output the query-index-weighted sum mod 1e9+7.	Hard8	Dynamic programmingGraph+1	No attempts yet	5.5s	2048 MB	Judgeable
FlowersGiven a rooted tree of N pots with water needs A_i, decide whether the first player wins the watering game when both players play optimally.	Hard8	Game theoryTree+1	No attempts yet	1s	1024 MB	Judgeable
Intimate ChefGiven chefs with two tastiness values and forbidden pairs, find the satisfaction of the X-th best allowed chef pair for each query.	Hard8	SortingHeap+1	No attempts yet	3s	2048 MB	Judgeable
Moderation in all thingsAfter each operation on an array that starts as [0], print its middle element. Inserts take the next natural numbers in order.	Hard8	Linked listTree+1	No attempts yet	1s	2048 MB	Judgeable