Problems

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Total results29,447 problems

TV Show
Medium5
Probability, Math+2
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Black-Red Square
Medium5
Implementation, Simulation+2
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Postal Shipment
Medium5
Dynamic programming, Bit manipulation+2
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Tea Break
Medium5
Binary search, Greedy+2
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
k-sorting
Medium5
Sorting, Greedy+2
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Tiny - 4
Medium5
Simulation, Backtracking
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Mines - 3
Medium5
Simulation, Matrix+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Mines - 9
Medium5
Greedy, Implementation+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Gahui and the Suin-Bundang Line 1
Medium5
Simulation, Implementation+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Villain Hoseok
Medium5
Brute force, Implementation+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Competition
Medium5
Greedy, Sorting+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Neighborhood Watch
Medium5
Math, Combinatorics+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
cubic
Medium5
Math, Number theory+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Cipher
Medium5
String, Brute force+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
On-Call
Medium5
Simulation, Sliding window+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Curry Making
Medium5
Math, Binary search+1
No attempts yet
Time limit
8s
Memory limit
512 MB
Judgeable
Airport Codes
Medium5
String, Hash map+2
No attempts yet
Time limit
8s
Memory limit
512 MB
Judgeable
JAG-channel
Medium5
Implementation, Tree+2
No attempts yet
Time limit
8s
Memory limit
512 MB
Judgeable
Invest Master
Medium5
Dynamic programming, Greedy+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Final Defense Line
Medium5
Geometry, Implementation
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
ReverseSort
Medium5
BFS, Brute force+2
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Calender Colors
Medium5
Brute force, Combinatorics+2
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Brave Force Story
Medium5
BFS, Graph+2
No attempts yet
Time limit
8s
Memory limit
512 MB
Judgeable
Inviting Friends
Medium5
Intervals, Sorting+2
No attempts yet
Time limit
8s
Memory limit
512 MB
Judgeable
Kaeru Jump
Medium5
Backtracking, DFS+1
No attempts yet
Time limit
8s
Memory limit
512 MB
Judgeable
Ropeway
Medium5
Greedy, Math+1
No attempts yet
Time limit
8s
Memory limit
512 MB
Judgeable
CatChecker
Medium5
String, Dynamic programming+2
No attempts yet
Time limit
8s
Memory limit
512 MB
Judgeable
Symmetry
Medium5
Geometry, Hash map
No attempts yet
Time limit
8s
Memory limit
512 MB
Judgeable
Cache Control
Medium5
Hash map, Linked list+2
No attempts yet
Time limit
8s
Memory limit
512 MB
Judgeable
Bitwise Kingdom
Medium5
Combinatorics, Binary search+2
No attempts yet
Time limit
8s
Memory limit
512 MB
Judgeable
Osaki
Medium5
Greedy, Sorting+2
No attempts yet
Time limit
8s
Memory limit
512 MB
Judgeable
Goofy Converter
Medium5
Greedy, Sliding window+2
No attempts yet
Time limit
8s
Memory limit
512 MB
Judgeable
Restaurant
Medium5
Simulation, Implementation+2
No attempts yet
Time limit
8s
Memory limit
512 MB
Judgeable
Merging Maps
Medium5
Brute force, Simulation+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Building a Space Station
Medium5
Minimum spanning tree, Graph+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Get a Rectangular Field
Medium5
Brute force, Array+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
File Compression
Medium5
String matching, Implementation+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Lost in Space
Medium5
Geometry, Brute force+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Rational Irrationals
Medium5
Math, Number theory+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Certified Easy Game
Medium5
Game theory, Dynamic programming+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Longest Even Contiguous Subsequence (small)
Medium5
Sliding window, Two pointers+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Restore the Original (small)
Medium5
Array, Simulation+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
HTML Parsing
Medium5
String, Implementation+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Folder Cleanup (small)
Medium5
Tree, DFS+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Longest Even Contiguous Subsequence (Large)
Medium5
Sliding window, Two pointers+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Crossing the Stepping Stones (small)
Medium5
Dynamic programming, Array+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Retiling
Medium5
Greedy, Sorting+2
No attempts yet
Time limit
40s
Memory limit
1024 MB
Judgeable
Binary Search Game
Medium5
Game theory, Dynamic programming+1
No attempts yet
Time limit
30s
Memory limit
1024 MB
Judgeable
Cookie Crew
Medium5
BFS, Graph+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Rotating maze zone search
Medium5
BFS, Graph+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Dodo the Cat's Escape
Medium5
Shortest path, Matrix+1
No attempts yet
Time limit
4s
Memory limit
1024 MB
Judgeable
conv1d
Medium5
Math, Combinatorics+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Number of Increasing Subsequences
Medium5
Dynamic programming, Prefix sum+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Image Shrinking
Medium5
Implementation, Brute force+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Checksum
Medium5
Graph, Union-find+2
No attempts yet
Time limit
Not set
Memory limit
1024 MB
Judgeable
Smaller Strings
Medium5
Math, String+2
No attempts yet
Time limit
Not set
Memory limit
1024 MB
Judgeable
Shuffled Anagrams
Medium5
Greedy, Sorting+2
No attempts yet
Time limit
Not set
Memory limit
1024 MB
Judgeable
The Tasting Corner Is Mine
Medium5
Dynamic programming, Array+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Nutella Tree (Easy)
Medium5
Tree, DFS+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Challenge Number King
Medium5
Dynamic programming, Bit manipulation+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Flip Game
Medium5
Brute force, Bit manipulation+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Coloring Natural Numbers 2
Medium5
Number theory, Math
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Bee Seungyeon
Medium5
Dynamic programming, Matrix+1
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Coin Flipping
Medium5
Greedy, Math+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Candy Tree
Medium5
Tree, DFS+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Polish Notation
Medium5
Stack, Recursion+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Genetic Search
Medium5
String, Hash map+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
My Bad
Medium5
Simulation, Brute force+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Fikapaus
Medium5
Geometry, Math+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Data Structures Are Really the Best
Medium5
Stack, Simulation+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Cloud Bridge 2
Medium5
Graph, Greedy+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Banana Bunches
Medium5
Sliding window, Prefix sum+1
No attempts yet
Time limit
20s
Memory limit
1024 MB
Judgeable
Grazed Grains
Medium5
Geometry, Probability+2
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Joint Jog Jam
Medium5
Geometry, Math+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Entopia's Memory Boost
Medium5
Dynamic programming, Array+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Terminal Sequence
Medium5
Tree, Implementation+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Rolling the Dice 2
Medium5
Simulation, Implementation+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Fish Tank Arrangement
Medium5
Simulation, Implementation+1
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Choosing Study Time 2
Medium5
Prefix sum, Intervals+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
The Fossil Excavation Event Finally Begins
Medium5
DFS, Implementation+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
A Pleasant Homework Life
Medium5
Math, Binary search+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Rolling a Marble
Medium5
Dynamic programming, Combinatorics+2
No attempts yet
Time limit
0.5s
Memory limit
1024 MB
Judgeable
Graduation Photo
Medium5
Hash map, Sorting+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
K Logistics Warehouse
Medium5
Simulation, Stack+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Match Fixing
Medium5
Array, Brute force+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Quack Strikes Back (Hard)
Medium5
Implementation
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Fair Play
Medium5
Hash map, Sorting+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Handling the Blocks
Medium5
Graph, Union-find+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
No Luck
Medium5
Sorting, Prefix sum+2
No attempts yet
Time limit
2s
Memory limit
1024 MB
Judgeable
Multiplication and Division by 2
Medium5
Bit manipulation, Math+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Removing Pairs
Medium5
String, Dynamic programming+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Ants
Medium5
BFS, Graph+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Cubic polynomials
Medium5
Number theory, Hash map+1
No attempts yet
Time limit
1.5s
Memory limit
256 MB
Judgeable
Planet of the singles
Medium5
Greedy, Prefix sum
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Wise man
Medium5
Simulation, Hash map+1
No attempts yet
Time limit
1s
Memory limit
64 MB
Judgeable
Meal
Medium5
Greedy, Sorting+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Wall Climbing
Medium5
Graph, BFS+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Drone With a Camera
Medium5
Geometry, Math
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Hobby
Medium5
Backtracking, Brute force+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Product
Medium5
Math, Array+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable

Title	Level	Topics	Solved	Time limit	Memory limit	Judge
TV ShowFor each n, compute the expected number of bridge crossings a contestant makes walking from island 1 to island n when each pair of bridges has one random collapse.	Medium5	ProbabilityMath+2	No attempts yet	2s	256 MB	Judgeable
Black-Red SquareConstruct a rolling-square walk on a grid that paints exactly r cells red and b cells black, where the color of each visited cell alternates.	Medium5	ImplementationSimulation+2	No attempts yet	2s	256 MB	Judgeable
Postal ShipmentSplit up to 14 items into parcels so that each parcel costs its total weight in rubles, except parcels of exactly 1000 grams which cost P, and minimize the total.	Medium5	Dynamic programmingBit manipulation+2	No attempts yet	2s	256 MB	Judgeable
Tea BreakEach of n employees has a set of favorite tea kinds, and given a_i bags of each kind, find how many days everyone can drink a favorite tea.	Medium5	Binary searchGreedy+2	No attempts yet	2s	256 MB	Judgeable
k-sortingGiven an array and a fixed step k, find the minimum number of swaps of elements exactly k positions apart needed to sort the array in nondecreasing order, or -1 if impossible.	Medium5	SortingGreedy+2	No attempts yet	2s	256 MB	Judgeable
Tiny - 4Given a sequence of Tiny pieces that cannot be rotated or moved sideways, choose a drop column for each so every piece lands fully inside the 9x9 container.	Medium5	SimulationBacktracking	No attempts yet	1s	512 MB	Judgeable
Mines - 3Given the count of mines in each cell's 3x3 neighborhood, restore the original mine grid by determining cells row by row.	Medium5	SimulationMatrix+1	No attempts yet	1s	512 MB	Judgeable
Mines - 9Given the 3x3 neighborhood mine counts for each cell of an H by W grid, restore which cells contain mines.	Medium5	GreedyImplementation+1	No attempts yet	1s	512 MB	Judgeable
Gahui and the Suin-Bundang Line 1Given downbound train schedules with fixed per-segment travel times and 20-second dwells, find the earliest arrival at K272 when starting from K225 at a given time.	Medium5	SimulationImplementation+2	No attempts yet	1s	512 MB	Judgeable
Villain HoseokCount how many K-digit displays (with leading zeros, value 1 to N) can be reached from the current display by flipping 1 to P of the seven-segment LEDs.	Medium5	Brute forceImplementation+2	No attempts yet	1s	512 MB	Judgeable
CompetitionAssign every student to either a Physics team of size a or a Biology team of size b to maximize the total score.	Medium5	GreedySorting+1	No attempts yet	1s	512 MB	Judgeable
Neighborhood WatchGiven which houses on a line are watch houses, count the unordered pairs of houses whose connecting walk passes through at least one watch house.	Medium5	MathCombinatorics+2	No attempts yet	1s	512 MB	Judgeable
cubicGiven integer coefficients of a cubic, return every rational root, using the rational root theorem to test candidate divisors of the constant and leading terms.	Medium5	MathNumber theory+2	No attempts yet	1s	512 MB	Judgeable
CipherFor each Caesar-cipher message, try all 26 shifts, pick the one matching the most known threat and non-threat words, then print the plaintext and match percentages.	Medium5	StringBrute force+2	No attempts yet	1s	512 MB	Judgeable
On-CallCount how many times an alert turns on given a stream of per-minute error counts, a high threshold U, a low threshold L, and a window length D.	Medium5	SimulationSliding window+2	No attempts yet	2s	512 MB	Judgeable
Curry MakingGiven R0 grams of roux in W0 liters of water, find the smallest non-negative integer X of R-gram roux pieces to add (with any water) so the concentration becomes exactly C g/L.	Medium5	MathBinary search+1	No attempts yet	8s	512 MB	Judgeable
Airport CodesFor each set of airport names, find the smallest k so that the derived codes (first letter plus letters after vowels, truncated to k) are all distinct, or report -1.	Medium5	StringHash map+2	No attempts yet	8s	512 MB	Judgeable
JAG-channelEach line is a post indented by dots; redraw the dots as spaces, mark each post's own dot with '+', and draw '\|' between a parent and its descendants.	Medium5	ImplementationTree+2	No attempts yet	8s	512 MB	Judgeable
Invest MasterGiven predicted prices for n stocks over d days, buy and sell units to maximize cash on the last day, with no fees and no intraday price change.	Medium5	Dynamic programmingGreedy+2	No attempts yet	2s	512 MB	Judgeable
Final Defense LineGiven up to 5 polygons with gas concentrations and spawn and facility point pairs, find the minimum total damage a creature takes on its route.	Medium5	GeometryImplementation	No attempts yet	3s	512 MB	Judgeable
ReverseSortGiven a permutation of 1 to N, find the minimum number of subarray reversals needed to sort it into ascending order.	Medium5	BFSBrute force+2	No attempts yet	5s	512 MB	Judgeable
Calender ColorsChoose M of N Lab colors maximizing the sum of squared Euclidean distances over all pairs in the chosen subset.	Medium5	Brute forceCombinatorics+2	No attempts yet	5s	512 MB	Judgeable
Brave Force StoryCount how many hexagonal cells a piece can reach in at most t turns on a grid with obstacles, given axial coordinates and a starting cell.	Medium5	BFSGraph+2	No attempts yet	8s	512 MB	Judgeable
Inviting FriendsEach friend accepts a group size in [ai, bi]; the group includes me, so find the size s maximizing how many intervals contain s, then subtract one.	Medium5	IntervalsSorting+2	No attempts yet	8s	512 MB	Judgeable
Kaeru JumpFind a sequence of jumps for a frog on a grid of lily pads, where each departed leaf sinks, until only one leaf remains.	Medium5	BacktrackingDFS+1	No attempts yet	8s	512 MB	Judgeable
RopewayGiven packages in order, decide whether each one can be placed on a car of length L at distance at least R from the center without the moment sum exceeding M.	Medium5	GreedyMath+1	No attempts yet	8s	512 MB	Judgeable
CatCheckerDecide whether a string of m, e, w matches the grammar CAT := "" \| 'm' CAT 'e' CAT 'w'.	Medium5	StringDynamic programming+2	No attempts yet	8s	512 MB	Judgeable
SymmetryGiven N polygon vertices in arbitrary order, decide whether some line is a mirror axis that maps the vertex set onto itself.	Medium5	GeometryHash map	No attempts yet	8s	512 MB	Judgeable
Cache ControlSimulate an LRU cache of size M over N key accesses, then print the keys still cached from most to least recently used.	Medium5	Hash mapLinked list+2	No attempts yet	8s	512 MB	Judgeable
Bitwise KingdomGiven N and M, find the binary string of length N whose M-th lowest class ranking orders by popcount first, then lexicographic order.	Medium5	CombinatoricsBinary search+2	No attempts yet	8s	512 MB	Judgeable
OsakiGiven each train's departure and arrival times at Osaki on a loop line, find the minimum number of train cars (units) needed to cover all scheduled trips.	Medium5	GreedySorting+2	No attempts yet	8s	512 MB	Judgeable
Goofy ConverterGiven L and M, find a 0/1 sequence K of length N+M-1 with each L[j] equal to the sum of K[j..j+M-1], or report that none exists.	Medium5	GreedySliding window+2	No attempts yet	8s	512 MB	Judgeable
RestaurantSimulate a single-cook kitchen that batches identical dishes up to a per-dish limit and reports each customer's serving time.	Medium5	SimulationImplementation+2	No attempts yet	8s	512 MB	Judgeable
Merging MapsGiven several letter grids, repeatedly merge the pair with the highest overlay score by trying every offset, then print each merged map in a border.	Medium5	Brute forceSimulation+1	No attempts yet	2s	512 MB	Judgeable
Building a Space StationGiven n spheres in 3D, connect them all with minimum total corridor length, where two spheres are already linked if they touch or overlap.	Medium5	Minimum spanning treeGraph+2	No attempts yet	2s	512 MB	Judgeable
Get a Rectangular FieldFor each 5x5 grid of 0s and 1s, report the largest number of 1s contained in an all-ones axis-aligned rectangle.	Medium5	Brute forceArray+2	No attempts yet	2s	512 MB	Judgeable
File CompressionCompress each input segment by replacing repeated substrings of length 7 or more with a base64 reference to the longest, then earliest, earlier occurrence.	Medium5	String matchingImplementation+1	No attempts yet	2s	512 MB	Judgeable
Lost in SpaceGiven three reference side lengths and up to thirty 3D points, find the one triple whose triangle is similar to the reference within a tiny tolerance, and print its points in P, Q, R order.	Medium5	GeometryBrute force+2	No attempts yet	2s	512 MB	Judgeable
Rational IrrationalsFor each prime p and bound n, output the two fractions with numerator and denominator at most n that bracket sqrt(p) most tightly, in lowest terms.	Medium5	MathNumber theory+2	No attempts yet	2s	512 MB	Judgeable
Certified Easy GameStarting from 1, two players alternate adding a divisor of the current number to it; whoever pushes the value past K loses. Determine the winner under optimal play.	Medium5	Game theoryDynamic programming+2	No attempts yet	1s	1024 MB	Judgeable
Longest Even Contiguous Subsequence (small)Delete at most K elements from a sequence, then report the longest contiguous run of even numbers possible.	Medium5	Sliding windowTwo pointers+2	No attempts yet	1s	1024 MB	Judgeable
Restore the Original (small)Given the deck after K shuffles and the shuffle order D, recover the original arrangement by applying the inverse shuffle K times.	Medium5	ArraySimulation+2	No attempts yet	1s	1024 MB	Judgeable
HTML ParsingParse a one-line HTML document, and for each div print its title attribute followed by the cleaned text of every p tag inside it.	Medium5	StringImplementation+2	No attempts yet	1s	1024 MB	Judgeable
Folder Cleanup (small)Given a folder tree with files, answer queries that ask, for each folder, how many distinct file names and how many total files sit under it.	Medium5	TreeDFS+2	No attempts yet	1s	1024 MB	Judgeable
Longest Even Contiguous Subsequence (Large)Given a sequence, delete at most K elements so that some remaining contiguous run consists only of even numbers, and report the longest such run.	Medium5	Sliding windowTwo pointers+2	No attempts yet	1s	1024 MB	Judgeable
Crossing the Stepping Stones (small)Given stones with values A_i, decide if you can reach the last stone when each jump i to j costs (j-i)*(1+\|A_i-A_j\|) and no jump may exceed K.	Medium5	Dynamic programmingArray+2	No attempts yet	1s	1024 MB	Judgeable
RetilingGiven a grid of reversible two-color tiles and costs for flipping one tile or swapping two adjacent tiles, find the minimum cost to reach a target pattern.	Medium5	GreedySorting+2	No attempts yet	40s	1024 MB	Judgeable
Binary Search GameAlice and Bob alternately delete the left or right half of a 2L-cell board, and the task sums the final card score over all M^N card assignments.	Medium5	Game theoryDynamic programming+1	No attempts yet	30s	1024 MB	Judgeable
Cookie CrewOn an N x N grid with three of each topping type, find which topping type gives the shortest path from the house to the goal, visiting all three cells of that type.	Medium5	BFSGraph+2	No attempts yet	1s	512 MB	Judgeable
Rotating maze zone searchFind the fewest hours to reach the exit in a 4k by 4k maze where each hour you move or stay, then the 4x4 zone you stand in rotates 90 degrees clockwise.	Medium5	BFSGraph+1	No attempts yet	1s	1024 MB	Judgeable
Dodo the Cat's EscapeFind the minimum stamina Dodo the cat needs to reach the exit E, using flat moves, ladders, and falls through open-bottom cells while avoiding dogs.	Medium5	Shortest pathMatrix+1	No attempts yet	4s	1024 MB	Judgeable
conv1dSum the conv1d outputs over all X^(N+K) assignments of values in [1,X] to A and B, reporting each of the N-K+1 positions modulo 998244353.	Medium5	MathCombinatorics+1	No attempts yet	2s	1024 MB	Judgeable
Number of Increasing SubsequencesFor each position i, count the increasing subsequences that end at A_i, modulo 998244353, where values range up to 5000.	Medium5	Dynamic programmingPrefix sum+2	No attempts yet	2s	1024 MB	Judgeable
Image ShrinkingGiven an enlarged image formed by scaling each axis by an integer factor, recover an original image of smallest area.	Medium5	ImplementationBrute force+2	No attempts yet	2s	1024 MB	Judgeable
ChecksumGiven a partially corrupted N x N boolean matrix, its row and column XOR checksums, and recovery costs, find the minimum cost to reconstruct the matrix.	Medium5	GraphUnion-find+2	No attempts yet	Not set	1024 MB	Judgeable
Smaller StringsCount length-N palindromes over the first K letters that are lexicographically smaller than S, modulo 1e9+7.	Medium5	MathString+2	No attempts yet	Not set	1024 MB	Judgeable
Shuffled AnagramsGiven a string, output a permutation of its letters with no letter in its original position, or report that none exists.	Medium5	GreedySorting+2	No attempts yet	Not set	1024 MB	Judgeable
The Tasting Corner Is MineGiven the food counts at N stalls, pick a subset with no three consecutive picks (at most two in a row) that maximizes total food, where the second stall of any two consecutive picks contributes only half its food rounded down.	Medium5	Dynamic programmingArray+1	No attempts yet	2s	512 MB	Judgeable
Nutella Tree (Easy)Count paths in a red/black tree that start at a black vertex and continue through only red vertices, with at least two vertices.	Medium5	TreeDFS+2	No attempts yet	2s	1024 MB	Judgeable
Challenge Number KingGiven up to 20 card values, count how many integers from 1 to their total sum cannot be formed as a subset sum.	Medium5	Dynamic programmingBit manipulation+2	No attempts yet	1s	512 MB	Judgeable
Flip GameGiven an N x N grid of 0/1 cells, find the fewest operations (flip a whole row or column, or one cell) to make all cells equal.	Medium5	Brute forceBit manipulation+2	No attempts yet	1s	512 MB	Judgeable
Coloring Natural Numbers 2Color the natural numbers 1 to N so that any two non-coprime numbers get different colors, using the fewest colors possible.	Medium5	Number theoryMath	No attempts yet	1s	1024 MB	Judgeable
Bee SeungyeonCount paths on an N by M hexagonal grid from cell (1,1) to (N,M), moving only down, up-right, or down-right, while avoiding K hole cells, modulo 1e9+7.	Medium5	Dynamic programmingMatrix+1	No attempts yet	1s	1024 MB	Judgeable
Coin FlippingGiven a string of H and T coins, find the minimum number of moves, each flipping exactly K distinct coins, to make every coin show T, or -1 if impossible.	Medium5	GreedyMath+2	No attempts yet	1s	1024 MB	Judgeable
Candy TreeGiven a tree of N nodes and radius K, find the maximum number of nodes within distance K of some center node.	Medium5	TreeDFS+2	No attempts yet	1s	1024 MB	Judgeable
Polish NotationParse a prefix expression with +, -, * over integers and one-letter variables, then replace every variable-free subexpression with its computed value and print the result in prefix notation.	Medium5	StackRecursion+2	No attempts yet	2s	1024 MB	Judgeable
Genetic SearchFor each pair of DNA strings S and L, count exact occurrences in L of S, of every distinct one-deletion variant of S, and of every distinct one-insertion variant of S.	Medium5	StringHash map+2	No attempts yet	2s	1024 MB	Judgeable
My BadGiven a small acyclic logic circuit and observations of its inputs and outputs, decide whether it works or find the unique failing gate and its failure mode.	Medium5	SimulationBrute force+2	No attempts yet	2s	1024 MB	Judgeable
FikapausBoth people move at constant speed between consecutive destinations; find the time when the distance between them is smallest.	Medium5	GeometryMath+2	No attempts yet	2s	1024 MB	Judgeable
Data Structures Are Really the BestGiven M stacks of distinct books numbered 1 to N, decide whether repeatedly taking only top books can yield the order 1, 2, ..., N.	Medium5	StackSimulation+2	No attempts yet	1s	1024 MB	Judgeable
Cloud Bridge 2Color each building so adjacent buildings differ, and among all valid colorings output the one whose color sequence is lexicographically smallest.	Medium5	GraphGreedy+2	No attempts yet	1s	1024 MB	Judgeable
Banana BunchesGiven tree bunch counts, find the fewest trees to buy so the chosen trees form at most two contiguous blocks summing to exactly K, or -1 if impossible.	Medium5	Sliding windowPrefix sum+1	No attempts yet	20s	1024 MB	Judgeable
Grazed GrainsGiven up to 10 circles, output the area of their union within 10% relative error, which Monte Carlo sampling can approximate.	Medium5	GeometryProbability+2	No attempts yet	3s	1024 MB	Judgeable
Joint Jog JamBoth runners move at constant speed along straight lines from their start points to their end points; find the maximum distance between them over the run.	Medium5	GeometryMath+2	No attempts yet	1s	1024 MB	Judgeable
Entopia's Memory BoostOn a fixed 3x4 board with two thumbs that move one at a time, press a given sequence of cells minimizing movement plus press costs A and B.	Medium5	Dynamic programmingArray+2	No attempts yet	1s	1024 MB	Judgeable
Terminal SequenceGiven the Prufer-style removal sequence of a labeled tree, reconstruct all N-1 edges and print them in sorted order.	Medium5	TreeImplementation+2	No attempts yet	2s	1024 MB	Judgeable
Rolling the Dice 2A die rolls across an N by M grid, turning based on its bottom face versus the cell value, and each landing adds the value times the size of its equal-value connected region.	Medium5	SimulationImplementation+2	No attempts yet	2s	1024 MB	Judgeable
Fish Tank ArrangementSimulate the repeated fish addition, folding, and fish transfer steps until the maximum and minimum fish counts differ by at most K.	Medium5	SimulationImplementation+1	No attempts yet	2s	1024 MB	Judgeable
Choosing Study Time 2Given each participant's available time intervals and a fixed study duration T, choose the start time that maximizes the total overlapping attendance time.	Medium5	Prefix sumIntervals+2	No attempts yet	1s	512 MB	Judgeable
The Fossil Excavation Event Finally BeginsFind all non-touching square spiral fossils in an N by N grid, then print each fossil's center, side length, and orientation sorted by row and column.	Medium5	DFSImplementation+1	No attempts yet	1s	512 MB	Judgeable
A Pleasant Homework LifeAssignments are worked in cyclic order, skipping every M-th day as a rest day, and each needs Xi work days; find which assignment finishes first.	Medium5	MathBinary search+2	No attempts yet	2s	512 MB	Judgeable
Rolling a MarbleA marble starts at gap (0,0) and rolls down n rows, moving left or right at each row; count paths that pass through all m required gaps.	Medium5	Dynamic programmingCombinatorics+2	No attempts yet	0.5s	1024 MB	Judgeable
Graduation PhotoDeduplicate submissions by name, then find the (place, time) pair with the most people, breaking ties by lexicographically smallest place and earliest time.	Medium5	Hash mapSorting+2	No attempts yet	1s	512 MB	Judgeable
K Logistics WarehouseSimulate a rail of containers processed by priority, rearranging equal-priority stacks by weight and summing every weight lifted.	Medium5	SimulationStack+2	No attempts yet	1s	512 MB	Judgeable
Match FixingOn an N x N gomoku board, flip exactly one white stone to black so the longest run of black stones in a row, column, or diagonal is as long as possible.	Medium5	ArrayBrute force+2	No attempts yet	1s	512 MB	Judgeable
Quack Strikes Back (Hard)The statement gives only a title and a one million step execution limit, so the actual task is not shown.	Medium5	Implementation	No attempts yet	1s	1024 MB	Judgeable
Fair PlayGiven n people each with billiards and pool skill values, decide whether they can be split into pairs so every pair has identical total skill in both categories.	Medium5	Hash mapSorting+2	No attempts yet	2s	1024 MB	Judgeable
Handling the BlocksGiven N blocks with distinct numbers and a color each, you may swap any two blocks of the same color; decide if the blocks can be sorted by number.	Medium5	GraphUnion-find+2	No attempts yet	1s	1024 MB	Judgeable
No LuckFor each retired contestant, count how many of the f years right after their last appearance had at least p qualifying slots, but only when they missed the cut in that last year.	Medium5	SortingPrefix sum+2	No attempts yet	2s	1024 MB	Judgeable
Multiplication and Division by 2Given two uint32 values x and y, decide whether repeated multiplication by 2 mod 2^32 and floor division by 2 can turn x into y.	Medium5	Bit manipulationMath+2	No attempts yet	2s	512 MB	Judgeable
Removing PairsDecide whether string s can be obtained from string t by repeatedly deleting two adjacent characters, where each deletion removes any neighboring pair.	Medium5	StringDynamic programming+2	No attempts yet	2s	512 MB	Judgeable
AntsGiven a grid with numbered chairs and an anthill, ants leave one per second toward their assigned chairs; report how many ants annihilate on each second.	Medium5	BFSGraph+2	No attempts yet	1s	256 MB	Judgeable
Cubic polynomialsGiven n cubic polynomials with integer coefficients, find the integer that is a root of their product with the largest multiplicity, and report that multiplicity.	Medium5	Number theoryHash map+1	No attempts yet	1.5s	256 MB	Judgeable
Planet of the singlesGiven two hex-encoded binary strings, find the minimum cost to turn the first into the second using bit flips and adjacent swaps.	Medium5	GreedyPrefix sum	No attempts yet	2s	512 MB	Judgeable
Wise manGiven A, M, and N, each day replace A with (A + the largest digit of A) mod M, and print A on day N.	Medium5	SimulationHash map+1	No attempts yet	1s	64 MB	Judgeable
MealPick one of two daily menu items for N days, staying within a total budget X, to maximize the sum of tastiness ratings.	Medium5	GreedySorting+2	No attempts yet	1s	256 MB	Judgeable
Wall ClimbingOn a grid with walls, each step costs 1 second but moving between two cells that both touch a wall is free; find the minimum time from S to E.	Medium5	GraphBFS+2	No attempts yet	1s	256 MB	Judgeable
Drone With a CameraGiven two lines that do not pass through the origin, find the shortest route that starts at the origin, touches both lines, and returns to the origin.	Medium5	GeometryMath	No attempts yet	1s	256 MB	Judgeable
HobbyFill a 3x3 grid with the digits 1 to 9, distinct, so that four given 2x2 subsquare sums and three colour-class sums all match, or report that no grid works.	Medium5	BacktrackingBrute force+2	No attempts yet	1s	256 MB	Judgeable
ProductGiven up to 100,000 integers, decide whether one element equals the product of all the others and print such an element if it exists.	Medium5	MathArray+2	No attempts yet	1s	256 MB	Judgeable