Problems

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Total results29,416 problems

School Pairing
Medium6
Hash map, Prefix sum+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Asphalt Paving
Medium6
Graph, Dynamic programming+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Leveling the Tiles
Medium6
Graph, BFS+2
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Happy Sequence
Medium6
Math, Implementation+2
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Balanced Tree
Medium6
Tree, DFS+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Jumbled password
Medium6
String, String matching+2
No attempts yet
Time limit
0.5s
Memory limit
1024 MB
Judgeable
Zoning
Medium6
BFS, Graph+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Dice Betting
Medium6
Probability, Dynamic programming+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Hay Bales
Medium6
Greedy, String+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
House of Cards
Medium6
Math, Number theory+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Global Warming
Medium6
Graph, Dynamic programming+2
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Sure Bet
Medium6
Greedy, Sorting+1
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Rock Climbing
Medium6
BFS, Graph+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Volleyball Scores
Medium6
Simulation, Implementation
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Basketball rebound placement
Medium6
Brute force, Combinatorics+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Hidden Hierarchy
Medium6
Tree, Hash map+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Friend Palindrome
Medium6
Dynamic programming, Bit manipulation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Flow Free
Medium6
Backtracking, DFS+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Decisions, Decisions
Medium6
Dynamic programming, Divide and conquer+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Particle Collision
Medium6
Geometry, Simulation+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Designing the Toy
Medium6
Math, Greedy+2
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Pavers
Medium6
Dynamic programming, Combinatorics+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
The Components Game
Medium6
Graph, DFS+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Club Room Repairs
Medium6
Greedy, Sorting+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Birthday Gift Sequence
Medium6
Math, Combinatorics+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
A Strange Tournament
Medium6
Dynamic programming, Divide and conquer+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Lawn Mowing
Medium6
Math, Greedy+2
No attempts yet
Time limit
1s
Memory limit
64 MB
Judgeable
Card block reversal
Medium6
Array, Hash map+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Barareh on Fire
Medium6
BFS, Graph
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Football Association Election
Medium6
Brute force, Bit manipulation+2
No attempts yet
Time limit
3s
Memory limit
64 MB
Judgeable
Roof
Medium6
Array, Prefix sum+2
No attempts yet
Time limit
1.5s
Memory limit
128 MB
Judgeable
Spirals
Medium6
Implementation, Simulation+2
No attempts yet
Time limit
1s
Memory limit
64 MB
Judgeable
False cards
Medium6
Greedy, Sorting+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Tataramon
Medium6
Greedy, Sorting+2
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
A Packing Problem
Medium6
Geometry, Math+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Paasa Numbers
Medium6
Combinatorics, Dynamic programming+2
No attempts yet
Time limit
3s
Memory limit
512 MB
Judgeable
Expression
Medium6
Dynamic programming, Implementation+1
No attempts yet
Time limit
4s
Memory limit
512 MB
Judgeable
Frog Pushers
Medium6
Union-find, Graph+2
No attempts yet
Time limit
5s
Memory limit
512 MB
Judgeable
Harry Potter and the Vector Spell
Medium6
Graph, Union-find+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Greeting Card
Medium6
Hash map, Math+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Suspension Bridges
Medium6
Binary search, Math+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Enumerating Brackets
Medium6
Combinatorics, Dynamic programming+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Biology
Medium6
Combinatorics, Math+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Barn Painting
Medium6
Tree, Dynamic programming+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Haybale Feast
Medium6
Two pointers, Sliding window+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
My Cow Ate My Homework
Medium6
Array, Prefix sum+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Milk Measurement
Medium6
Sorting, Hash map+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
The Bovine Shuffle
Medium6
Graph, DFS+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Minimum edit
Medium6
Dynamic programming, String+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Kindergarten candy bags
Medium6
Binary search, Greedy+2
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
An Unfair Puzzle
Medium6
String, String matching+2
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable
Vitcoin Lottery at Moloco (Easy)
Medium6
Greedy, Sorting+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Tap Titanz at Moloco (Easy)
Medium6
Graph, BFS+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Array Manipulation at Moloco (Hard)
Medium6
Segment tree, Binary search+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Tournament Chart
Medium6
Tree, DFS+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Prime-Factor Prime
Medium6
Number theory, Math+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Farm Village
Medium6
Dynamic programming, Greedy
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Life Line
Medium6
Simulation, Graph+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Shredding Company
Medium6
Backtracking, Brute force+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Anagram Pyramids (Hard)
Medium6
Graph, DFS+1
No attempts yet
Time limit
10s
Memory limit
512 MB
Judgeable
if
Medium6
Math, Bit manipulation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Jump Game
Medium6
BFS, Graph+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Networks
Medium6
Graph, Greedy+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Frog 3
Medium6
Graph, Backtracking+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Lifeguards
Medium6
Intervals, Sorting+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Cow Rental Service
Medium6
Greedy, Sorting+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
MooTube (Silver)
Medium6
Graph, DFS+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
The Prices
Medium6
Dynamic programming, Bit manipulation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Fibonacci Number 7
Medium6
Dynamic programming, Math+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Pepper Wreath
Medium6
Tree, DFS+2
No attempts yet
Time limit
1s
Memory limit
1024 MB
Judgeable
Zagonetka
Medium6
Topological sort, Graph+1
No attempts yet
Time limit
3s
Memory limit
1024 MB
Judgeable
Thinking Station
Medium6
String, Hash map+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Marble Escape 3
Medium6
BFS, Simulation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Farmer Juan is a barista
Medium6
Prefix sum, Matrix+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Inserting Operators (2)
Medium6
Backtracking, Brute force+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Inserting Operators (3)
Medium6
Brute force, Backtracking+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Two teams with the smallest ability gap
Medium6
Bit manipulation, Brute force+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Room Number
Medium6
Brute force, Math+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
Dragon Curve
Medium6
Implementation, Recursion+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Comma Sprinkler
Medium6
Graph, BFS+2
No attempts yet
Time limit
8s
Memory limit
1024 MB
Judgeable
Stacking dice
Medium6
Greedy, Sorting+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Minecraft
Medium6
Greedy, Binary search+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Strawberry Carrot Watermelon Chamoe Melon Game
Medium6
Math, Binary search+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Eri Card
Medium6
Sorting, Greedy+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Escape Room
Medium6
Greedy, Array+2
No attempts yet
Time limit
1s
Memory limit
256 MB
Judgeable
The swimming pool owner
Medium6
Heap, Graph+2
No attempts yet
Time limit
2s
Memory limit
128 MB
Judgeable
Python syntax
Medium6
Dynamic programming, Implementation+2
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Hiding Acorns
Medium6
Binary search, Prefix sum+1
No attempts yet
Time limit
1s
Memory limit
128 MB
Judgeable
Reversing
Medium6
Array, Implementation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Directory Traversal
Medium6
Tree, DFS+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Taming the Herd
Medium6
Dynamic programming, Implementation+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Talent Show
Medium6
Dynamic programming, Binary search+1
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Sejin Virus
Medium6
Graph, DFS+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Parachute
Medium6
Math, Implementation+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Can the CTP Kingdom beat the Hansol Kingdom?
Medium6
Union-find, Graph+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Anagrams
Medium6
Greedy, Sorting+2
No attempts yet
Time limit
2s
Memory limit
512 MB
Judgeable
Tree Country Tour Guide
Medium6
Stack, Tree+1
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Yeongu Dorm Cleaning
Medium6
BFS, Graph+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Weekend Trip Plan
Medium6
Graph, Shortest path+2
No attempts yet
Time limit
1s
Memory limit
512 MB
Judgeable
Invader Jina
Medium6
Brute force, Math+2
No attempts yet
Time limit
2s
Memory limit
256 MB
Judgeable

Title	Level	Topics	Solved	Time limit	Memory limit	Judge
School PairingFor each query range, count pairs of positions whose skill grades sum to K.	Medium6	Hash mapPrefix sum+1	No attempts yet	2s	512 MB	Judgeable
Asphalt PavingGiven segments on a triangular grid, choose the largest subset so that no two share an endpoint at an acute angle.	Medium6	GraphDynamic programming+2	No attempts yet	1s	512 MB	Judgeable
Leveling the TilesGiven a grid of heights, each impact lowers one tile and all tiles connected to it at the same height; find the minimum impacts to make every tile equal.	Medium6	GraphBFS+2	No attempts yet	5s	512 MB	Judgeable
Happy SequenceChange a sequence with unit-cost edits so every interior term equals the sum of its two neighbours, minimizing total edits.	Medium6	MathImplementation+2	No attempts yet	3s	512 MB	Judgeable
Balanced TreeGiven a tree whose vertices each hold A or B, swap characters along edges so no edge joins equal letters, using the fewest swaps, or report -1.	Medium6	TreeDFS+2	No attempts yet	1s	512 MB	Judgeable
Jumbled passwordGiven a string, find the smallest index past the midpoint where the suffix differs from the prefix of equal length in exactly one character.	Medium6	StringString matching+2	No attempts yet	0.5s	1024 MB	Judgeable
ZoningGiven an n by n grid labeled 1, 2, 3, find the maximum over all cells labeled 1 of the Manhattan distance to the nearest cell labeled 3.	Medium6	BFSGraph+2	No attempts yet	2s	512 MB	Judgeable
Dice BettingCompute the probability that at least k distinct values appear when an s-sided die is rolled n times, and print it to nine decimals.	Medium6	ProbabilityDynamic programming+2	No attempts yet	2s	512 MB	Judgeable
Hay BalesGiven a string of C and P, each move sorts any three consecutive characters so all C come before all P; find the minimum number of moves to fully sort the whole row.	Medium6	GreedyString+2	No attempts yet	2s	512 MB	Judgeable
House of CardsGiven a lower bound h0, find the smallest height h >= h0 such that the total card count h(3h+1)/2 is divisible by 4.	Medium6	MathNumber theory+2	No attempts yet	2s	512 MB	Judgeable
Global WarmingThe friendships form a disjoint union of cliques, so each connected component of even size must be split into a perfect matching of minimum total cost.	Medium6	GraphDynamic programming+2	No attempts yet	5s	512 MB	Judgeable
Sure BetChoose a subset of quoted odds on two outcomes so that the minimum of the two payout totals minus the number of bets is maximized.	Medium6	GreedySorting+1	No attempts yet	2s	128 MB	Judgeable
Rock ClimbingGiven n anchor points and a four-limb climbing model with pairwise distance and height limits, find the fewest moves to touch location n.	Medium6	BFSGraph+2	No attempts yet	2s	512 MB	Judgeable
Volleyball ScoresTrack a sequence of volleyball touches and report the score, or flag a wrong serve.	Medium6	SimulationImplementation	No attempts yet	2s	512 MB	Judgeable
Basketball rebound placementGiven opposing and candidate positions plus rebound spot probabilities, choose 5 of n candidate spots to maximize expected points from the resulting fast-break race.	Medium6	Brute forceCombinatorics+2	No attempts yet	2s	512 MB	Judgeable
Hidden HierarchyBuild a directory tree from file paths, and print the smallest set of directories (expanding or collapsing as needed) that covers every directory whose total size is at least t.	Medium6	TreeHash map+2	No attempts yet	1s	512 MB	Judgeable
Friend PalindromeGiven a friendship graph on up to 20 students, find the largest number of students that can form a palindrome-like line where every student except the possible middle one is paired with a friend.	Medium6	Dynamic programmingBit manipulation+2	No attempts yet	2s	512 MB	Judgeable
Flow FreeGiven a 4x4 Flow Free board with 3 or 4 color pairs, decide whether all cells can be covered by non-crossing paths joining matching endpoints.	Medium6	BacktrackingDFS+1	No attempts yet	2s	512 MB	Judgeable
Decisions, DecisionsGiven the truth table of an n-variable boolean function, count the vertices in its unique minimal binary decision diagram.	Medium6	Dynamic programmingDivide and conquer+2	No attempts yet	2s	512 MB	Judgeable
Particle CollisionThree equal circles at rest; particle 1 moves along a given vector and transfers motion on contact. Decide which of five collision chains occurs.	Medium6	GeometrySimulation+2	No attempts yet	1s	512 MB	Judgeable
Designing the ToyGiven three target projection areas a, b, c, find the minimum number of voxels in a 3D figure whose three orthogonal projections have those exact areas, or report -1.	Medium6	MathGreedy+2	No attempts yet	3s	512 MB	Judgeable
PaversCount the tilings of a 2 x n board with 1x1 squares, 2x1 rectangles, and L-trominoes, and sum the total number of each paver over all tilings.	Medium6	Dynamic programmingCombinatorics+2	No attempts yet	2s	512 MB	Judgeable
The Components GameFor each board, pick the single column to turn entirely black that maximizes the total number of same-color connected regions, breaking ties by more white regions.	Medium6	GraphDFS+2	No attempts yet	2s	512 MB	Judgeable
Club Room RepairsAssign each club at most one room and each room at most one club, where Jongbin covers max(0, cost - budget) up to X total; maximize clubs housed.	Medium6	GreedySorting+2	No attempts yet	2s	512 MB	Judgeable
Birthday Gift SequenceFor each query (x, K), form every non-empty subset sum of {1, x, x^2, ...}, sort uniquely, and sum the K-th values over all queries modulo 1e9+7.	Medium6	MathCombinatorics+2	No attempts yet	2s	512 MB	Judgeable
A Strange TournamentGiven a sequence of distinct powers, choose a non-crossing knockout bracket minimizing the total absolute difference over all matches played.	Medium6	Dynamic programmingDivide and conquer+2	No attempts yet	2s	512 MB	Judgeable
Lawn MowingFor each N by M grid, find the minimum number of 90-degree turns a lawn mower needs to cover every cell, starting anywhere in any direction.	Medium6	MathGreedy+2	No attempts yet	1s	64 MB	Judgeable
Card block reversalGiven a permutation of 1..N, choose one contiguous block to reverse so that the final number of positions i with card i is maximized, breaking ties by leftmost start then leftmost end.	Medium6	ArrayHash map+1	No attempts yet	1s	128 MB	Judgeable
Barareh on FireFind the shortest time from s to t on a grid where fire spreads to all eight neighbors every k seconds and blocks the path.	Medium6	BFSGraph	No attempts yet	2s	512 MB	Judgeable
Football Association ElectionGiven N ranked ballots over M candidates, find the current winner and the fewest candidates to remove so that candidate K wins.	Medium6	Brute forceBit manipulation+2	No attempts yet	3s	64 MB	Judgeable
RoofGiven N column heights, pick a peak position and height so the roof shape h_j = peak - \|peakpos - j\| is positive everywhere, minimizing total absolute changes.	Medium6	ArrayPrefix sum+2	No attempts yet	1.5s	128 MB	Judgeable
SpiralsK spirals walk outward with run lengths 1,1,2,2,... on an N by M grid; for each cell print the earliest step any spiral reached it, within a 10^100 step limit.	Medium6	ImplementationSimulation+2	No attempts yet	1s	64 MB	Judgeable
False cardsArrange N cards so exactly K are false, where each card claims at least a_i cards below it are false; output the specified canonical arrangement or -1.	Medium6	GreedySorting+2	No attempts yet	2s	512 MB	Judgeable
TataramonGiven a sequence, pick each value at most twice to maximize the sum, and among all maximum-sum picks output the lexicographically smallest subsequence.	Medium6	GreedySorting+2	No attempts yet	3s	512 MB	Judgeable
A Packing ProblemGiven a rectangle and two circles, decide whether both circles fit inside the rectangle without overlapping, allowing tangency.	Medium6	GeometryMath+2	No attempts yet	2s	512 MB	Judgeable
Paasa NumbersFind the Nth positive integer whose digits never increase from left to right, given N up to 10^18 and 10^4 queries.	Medium6	CombinatoricsDynamic programming+2	No attempts yet	3s	512 MB	Judgeable
ExpressionFor each pair (x, y) print a postfix expression over x, +, -, *, / whose value is y, using the fixed construction the statement describes.	Medium6	Dynamic programmingImplementation+1	No attempts yet	4s	512 MB	Judgeable
Frog PushersAfter channels are cut one by one in a fixed order, report the minimum spanning forest weight of the surviving graph before each cut, or FAIL if it is disconnected.	Medium6	Union-findGraph+2	No attempts yet	5s	512 MB	Judgeable
Harry Potter and the Vector SpellEach of N columns is a binary vector with exactly two 1s; find the rank of this M-by-N matrix over GF(2).	Medium6	GraphUnion-find+2	No attempts yet	1s	256 MB	Judgeable
Greeting CardCount how many pairs of given lattice points lie exactly 2018 units apart.	Medium6	Hash mapMath+2	No attempts yet	2s	512 MB	Judgeable
Suspension BridgesGiven the span and the sag of a hanging cable, solve the catenary equation for its parameter and print the cable length to six decimals.	Medium6	Binary searchMath+2	No attempts yet	2s	512 MB	Judgeable
Enumerating BracketsGiven N and M, print the M-th balanced bracket sequence of length N in lexicographic order, where '(' is smaller than ')'.	Medium6	CombinatoricsDynamic programming+2	No attempts yet	2s	512 MB	Judgeable
BiologyCount the possible five-card hands for each of nine poker categories, given two fixed cards from a deck with A ranks and B suits.	Medium6	CombinatoricsMath+2	No attempts yet	2s	512 MB	Judgeable
Barn PaintingCount the proper 3-colorings of a tree consistent with some pre-colored nodes, modulo 1e9+7.	Medium6	TreeDynamic programming+2	No attempts yet	2s	512 MB	Judgeable
Haybale FeastPick a contiguous block whose flavor sums to at least M while minimizing the block's maximum spiciness.	Medium6	Two pointersSliding window+2	No attempts yet	2s	512 MB	Judgeable
My Cow Ate My HomeworkFor each prefix length K that the cow ate, compute the average after dropping the single lowest remaining score, and list every K that maximizes it.	Medium6	ArrayPrefix sum+2	No attempts yet	2s	512 MB	Judgeable
Milk MeasurementSort the measurements by day, then count the days where the set of cows with the maximum current milk output changes after applying each update.	Medium6	SortingHash map+2	No attempts yet	2s	512 MB	Judgeable
The Bovine ShuffleGiven a functional graph where each position i sends its cow to a_i, count the positions that hold at least one cow no matter how many shuffles are applied.	Medium6	GraphDFS+2	No attempts yet	2s	512 MB	Judgeable
Minimum editCompute the Levenshtein distance between two lowercase strings, using the fewest insert, delete, and replace operations to change A into B.	Medium6	Dynamic programmingString+2	No attempts yet	2s	512 MB	Judgeable
Kindergarten candy bagsAssign N candy bags to N children to minimize the largest absolute difference between each child's candy and the candy of the child they picked; the picking forms a permutation.	Medium6	Binary searchGreedy+2	No attempts yet	2s	256 MB	Judgeable
An Unfair PuzzleGiven two permutations of 1..n, decide whether cyclic rotations and reversals can turn the first into the second, printing good puzzle or bad puzzle.	Medium6	StringString matching+2	No attempts yet	2s	256 MB	Judgeable
Vitcoin Lottery at Moloco (Easy)Order n tickets with prizes w_i and continuation probabilities p_i to maximize the expected sum of collected prizes, breaking ties by the lexicographically smallest permutation.	Medium6	GreedySorting+2	No attempts yet	2s	512 MB	Judgeable
Tap Titanz at Moloco (Easy)On an n by n black/white board, each tap flips a whole same-color connected region; find the minimum taps to make the board one color.	Medium6	GraphBFS+2	No attempts yet	2s	512 MB	Judgeable
Array Manipulation at Moloco (Hard)For each position i in a permutation-like array, count how many earlier elements are smaller than A[i], with n up to one million.	Medium6	Segment treeBinary search+2	No attempts yet	2s	512 MB	Judgeable
Tournament ChartParse a knockout bracket given as a string and decide whether the reported win counts for all players can be consistent with some assignment of match winners.	Medium6	TreeDFS+2	No attempts yet	2s	512 MB	Judgeable
Prime-Factor PrimeCount integers in [l, r] whose number of prime factors counted with multiplicity, written Omega(n), is itself prime.	Medium6	Number theoryMath+2	No attempts yet	2s	512 MB	Judgeable
Farm VillageEach house along a road needs one crop unit and can grow up to two; minimize the total growing cost plus cost of carrying crops between neighbors.	Medium6	Dynamic programmingGreedy	No attempts yet	2s	512 MB	Judgeable
Life LineOn a triangular board of numbered stones, place one stone so the turn's score (opponents' stones removed minus your own removed) is maximized.	Medium6	SimulationGraph+2	No attempts yet	2s	512 MB	Judgeable
Shredding CompanySplit a digit string into contiguous pieces so their sum is as large as possible without exceeding a target, reporting rejection on ties and error when even the smallest sum is too big.	Medium6	BacktrackingBrute force+2	No attempts yet	2s	512 MB	Judgeable
Anagram Pyramids (Hard)Given a dictionary and query word pairs, decide whether an anagram pyramid can be built from the top word down to the bottom word.	Medium6	GraphDFS+1	No attempts yet	10s	512 MB	Judgeable
ifConstruct a value x of type int or long such that x != 0 and x == -x, exploring two's complement overflow wrap-around.	Medium6	MathBit manipulation+2	No attempts yet	2s	512 MB	Judgeable
Jump GameOn two rows of cells that vanish one column per second from the left, decide whether the player can reach past the right end using forward, backward, and cross-row jumps.	Medium6	BFSGraph+1	No attempts yet	2s	512 MB	Judgeable
NetworksGiven M directed edges on N ordered systems, repeatedly merge any pair of edges A->B and B->C into A->C; find how many edges remain at the end.	Medium6	GraphGreedy+2	No attempts yet	1s	256 MB	Judgeable
Frog 3Assign each frog to a preferred pad so that every pair of pads joined by a log holds frogs with equal interest for that log's topic.	Medium6	GraphBacktracking+2	No attempts yet	1s	256 MB	Judgeable
LifeguardsFire exactly one of N given time intervals, then maximize the total length of time covered by at least one of the remaining intervals.	Medium6	IntervalsSorting+1	No attempts yet	2s	512 MB	Judgeable
Cow Rental ServiceChoose for each cow whether to milk it or rent it, matching milk to stores with limited quantity and price, to maximize total cents.	Medium6	GreedySorting+2	No attempts yet	2s	512 MB	Judgeable
MooTube (Silver)Given a weighted tree, for each query (k, v) count the vertices whose bottleneck distance (minimum edge on the path) from v is at least k.	Medium6	GraphDFS+1	No attempts yet	2s	512 MB	Judgeable
The PricesChoose for each product a wholesaler to buy it from, paying each visited wholesaler's round-trip cost once, to minimize the total.	Medium6	Dynamic programmingBit manipulation+2	No attempts yet	2s	512 MB	Judgeable
Fibonacci Number 7Compute the n-th Fibonacci number modulo 1,000,000,007 for n up to one million.	Medium6	Dynamic programmingMath+1	No attempts yet	1s	512 MB	Judgeable
Pepper WreathGiven a tree whose vertices carry non-negative weights and a cap k, find the minimum number of edges to cut so every resulting component has total weight at most k.	Medium6	TreeDFS+2	No attempts yet	1s	1024 MB	Judgeable
ZagonetkaFind the lexicographically smallest and largest permutations that satisfy hidden conditions p_a < p_b, using at most 5000 membership queries.	Medium6	Topological sortGraph+1	No attempts yet	3s	1024 MB	Judgeable
Thinking StationFor each K from 1 to N, split the first N cars into blocks of K (dropping the remainder) and count distinct blocks up to reversal; report the K values with the maximum count.	Medium6	StringHash map+2	No attempts yet	1s	256 MB	Judgeable
Marble Escape 3Tilt a small grid board to roll a red and a blue marble until one falls in the single hole; find the shortest tilt sequence that drops red and not blue, breaking ties lexicographically.	Medium6	BFSSimulation+2	No attempts yet	2s	512 MB	Judgeable
Farmer Juan is a baristaMaintain a grid under range-add rectangle updates and point queries, answering each point query using only earlier updates.	Medium6	Prefix sumMatrix+2	No attempts yet	2s	512 MB	Judgeable
Inserting Operators (2)Insert one of +, -, x, / between each adjacent pair from a limited supply, evaluating left to right with C++14 integer division, and report the largest and smallest results.	Medium6	BacktrackingBrute force+2	No attempts yet	2s	512 MB	Judgeable
Inserting Operators (3)Place the given +, -, *, / operators between N numbers to form an expression, then report the largest and smallest values it can take.	Medium6	Brute forceBacktracking+2	No attempts yet	2s	512 MB	Judgeable
Two teams with the smallest ability gapSplit N people into two nonempty teams so the difference between the two teams' pairwise ability sums is minimized, and print that minimum.	Medium6	Bit manipulationBrute force+2	No attempts yet	2s	512 MB	Judgeable
Room NumberFind natural numbers A and B with A + B = N, no leading zeros, and no digit repeated across both numbers, minimizing A.	Medium6	Brute forceMath+2	No attempts yet	1s	256 MB	Judgeable
Dragon CurveGenerate the segments of N dragon curves on a 101 by 101 grid, mark the grid points they pass through, and count unit squares whose four corners are all marked.	Medium6	ImplementationRecursion+2	No attempts yet	1s	512 MB	Judgeable
Comma SprinklerGiven a text, repeatedly add commas before or after every occurrence of a word that already has a comma on that side, until nothing changes; print the result.	Medium6	GraphBFS+2	No attempts yet	8s	1024 MB	Judgeable
Stacking dicePartition N dice into the fewest towers, where a tower lists dice top to bottom so the i-th die has at most s_i dice above it.	Medium6	GreedySorting+2	No attempts yet	2s	512 MB	Judgeable
MinecraftGiven N rocks in a row with swing costs K_i, moving costs P, and budget T, find the maximum number of stones that can be collected.	Medium6	GreedyBinary search+2	No attempts yet	1s	128 MB	Judgeable
Strawberry Carrot Watermelon Chamoe Melon GameGiven n words repeated in a b-beat cycle, find the turn on which a target word is shouted for the X-th time.	Medium6	MathBinary search+2	No attempts yet	1s	128 MB	Judgeable
Eri CardGiven N shared cards and N team cards, an opponent blocks K team cards to minimize our best product; find the maximum score we can still achieve.	Medium6	SortingGreedy+2	No attempts yet	1s	128 MB	Judgeable
Escape RoomEach press toggles one button and up to two buttons to its right; find the fewest presses to turn an all-off row of N lights into a target 0/1 pattern.	Medium6	GreedyArray+2	No attempts yet	1s	256 MB	Judgeable
The swimming pool ownerGiven an N by M grid of heights, compute how much water the terrain traps, where each cell's water level is the lowest possible maximum height along any path to the border.	Medium6	HeapGraph+2	No attempts yet	2s	128 MB	Judgeable
Python syntaxGiven a string of for and execute statements, count the valid Python indentation schemes modulo 1,000,000,007.	Medium6	Dynamic programmingImplementation+2	No attempts yet	1s	128 MB	Judgeable
Hiding AcornsGiven K arithmetic-progression rules marking boxes, find the box number where the D-th acorn is placed, counting boxes in increasing order.	Medium6	Binary searchPrefix sum+1	No attempts yet	1s	128 MB	Judgeable
ReversingGiven prefix or suffix reversals applied to an array, track where the element originally at position K ends up after all operations.	Medium6	ArrayImplementation+2	No attempts yet	2s	512 MB	Judgeable
Directory TraversalGiven a directory tree, choose a directory that minimizes the total length of all relative paths from it to every file.	Medium6	TreeDFS+2	No attempts yet	2s	512 MB	Judgeable
Taming the HerdGiven a log of N counter readings, find for each possible number of breakouts the minimum number of entries that disagree with some valid breakout sequence that starts with a breakout on day 1.	Medium6	Dynamic programmingImplementation+2	No attempts yet	2s	512 MB	Judgeable
Talent ShowChoose a group of cows with total weight at least W maximizing the ratio of total talent to total weight, and print floor(1000A).	Medium6	Dynamic programmingBinary search+1	No attempts yet	2s	512 MB	Judgeable
Sejin VirusGiven a directed graph of facilities and pipes, find the minimum number of starting nodes from which all nodes are reachable.	Medium6	GraphDFS+1	No attempts yet	1s	512 MB	Judgeable
ParachuteGiven fall speed, parachute glide speed, a walk speed, and cars parked at integer x positions, find the minimum time to reach the safe zone at x = Xe.	Medium6	MathImplementation+2	No attempts yet	1s	512 MB	Judgeable
Can the CTP Kingdom beat the Hansol Kingdom?Alliances partition kingdoms into connected components; starting from the CTP component, pick at most K other components to merge, in decreasing size, avoiding the component of the Hansol Kingdom.	Medium6	Union-findGraph+2	No attempts yet	1s	512 MB	Judgeable
AnagramsGiven two equal-length uppercase strings A and B, find the minimum total number of cyclic letter increments applied to positions of A so the result is an anagram of B.	Medium6	GreedySorting+2	No attempts yet	2s	512 MB	Judgeable
Tree Country Tour GuideGiven the move sequence of a shortest round trip that visits every node of an unknown rooted tree, reconstruct each city's parent.	Medium6	StackTree+1	No attempts yet	1s	512 MB	Judgeable
Yeongu Dorm CleaningA knight moves mold around an N by N board for exactly t days; report whether any of K inspected cells holds mold at day t.	Medium6	BFSGraph+2	No attempts yet	1s	512 MB	Judgeable
Weekend Trip PlanGiven a weighted graph and separate destination and lodging values at each location, find the maximum of w_a + w_b - dist(a, b) over all destination-lodging pairs.	Medium6	GraphShortest path+2	No attempts yet	1s	512 MB	Judgeable
Invader JinaPlace two poison sources on empty cells of an N by M grid so that the maximum Manhattan distance from any village to its nearest source is minimized.	Medium6	Brute forceMath+2	No attempts yet	2s	256 MB	Judgeable